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January 31, 2011

Two-part storm due; up to half-inch of ice possible

The National Weather Service has split its forecast for the coming, two-part ice storm and expanded the area affected. Up to a half-inch of ice is possible by Wednesday morning  for communities along the Pennsylvania border. A quarter-inch is possible in Baltimore.

First, there is now a Winter Weather Advisory posted tonight for all the northern tier of counties along the Pennsylvania line, as well as for Montgomery, Howard, Prince George's and Anne Arundel Counties and the northern counties of the Eastern Shore.

The Advisory is in effect from midnight Tuesday morning to noon. Along the northern border it calls for sleet beginning this evening, changing to freezing rain after midnight tonight, with one- to two-tenths of an inch of ice accumulation by Tuesday morning.

Lesser amounts - a few hundredths of an inch - are likely to the south and east, including Anne Arundel County.

The precipitation may pause during the day Tuesday, much as it did during last Wednesday's storm. But heavier accumulations of ice are forecast for the region as the freezing rain resumes later in the day.

Up to a quarter-inch of new ice is possible before it all ends Wednesday, forecasters said in a Winter Storm Watch posted for that period. The forecast ice accumulation map, however, shows up to a half-inch along the Pa. border, and a quarter-inch of more north and west of U.S. 40, including Baltimore.

Posted by Frank Roylance at 4:03 PM | | Comments (7)
Categories: Forecasts
        

Commuters: This one will be icy

Maryland commuters, especially those who left for home too late last Wednesday and got stuck in the snow, should be paying attention to the weather forecast today. This is not going to be a big snow event. But the forecast for snow, sleet, and long periods of freezing rain are likely to affect the Tuesday morning commute. It's not something you can afford to shrug off.

Here's how Eric the Red is phrasing the outlook this afternoon:  "This is really, really gonna suck, big, big time, especially in the counties along the PA border."

"...[F]or tonight, sleet and freezing rain, perhaps starting as a brief period of snow. Precip will be light, which when it comes to freezing rain is not good because the ice will stick to everything. Models agree northern Maryland is under the gun, but differ on DC. Plan on a hairy morning commute tomorrow, and be thankful if you wake up to bare pavement."

"Even close to DC and the Bay, Tues morn's commute may be greeted with freezing rain as well.  Freezing rain will diminsh during the afternoon on Tues. ... Freezing rain and rain return in earnest Tues night into Weds morning, setting the stage for what could be a big-time ice storm across northern and western MD.  Along the I-95 corridor, expect mostly rain Tues night into Weds, but this area will be right on the ice/rain edge." 

The NWS has expanded the Winter Storm Watch to include Howard and Montgomery counties. It calls for snow and sleet developing tonight, changing to freezing rain overnight, with a quarter-inch NWS Mixed precipof ice - or more - accumulating.

"INTERMITTENT AND LIGHT FREEZING RAIN IS POSSIBLE DURING THE DAY TUESDAY. ON TUESDAY   NIGHT FREEZING RAIN IS EXPECTED TO INCREASE IN COVERAGE AND INTENSITY...AND CONTINUE THROUGH WEDNESDAY MORNING."

Forecasters don't expect the ice overnight tonight will warrant a Winter Storm Warning. But Tuesday night into Wednesday, higher precipitation amounts might eventually demand one.

The student forecasters at Foot's Forecast seem to agree: "High temperatures for areas further south across Central Virginia, Southern Maryland, and the lower Eastern Shore are expected to reach the mid 30s Tuesday, allowing any freezing rain early in the day to become all rain. Depending on the extent of cold air locked at the surface, areas near the Mason Dixon line into northern Delaware may experience an extended period of freezing rain into Tuesday night, with all rain for areas to the south."

The Tuesday night-into-Wednesday picture looks especially nasty. Eric lays it all out for you, on the jump:

"The second part of the storm is the main event, and this will arrive Tues night and last into mid-day Weds.  Temperatures will be critical.  The WRF/NAM [model] has a northeast wind locking in the cold air, and paints an ugly, ugly picture from northern MD into WV Tues night into Weds morning. 

"As a bonus, the WRF also has freezing rain falling almost all the way to the Bay and northern DC until ~ 5 am on Weds, again courtesy of a bonus round of northeast winds Tues night into early Weds.  The WRF liquid total is over an inch, and if it were to verify, would mean downed power lines and trees across much of the state. 

"On the other hand, the GFS [model] does not hold the cold air in place quite like the WRF, so it would be a cold, heavy rain for much of the I-95 corridor Tuesday night, but would likely still have ice across northern and western MD.  In short, the WRF would be awful, the GFS just merely unpleasant.

 

"Tues night - after midnight (we're gonna let it all hang down) - another round of freezing rain will arrive, but this will be heavy. 

"Closer to I-95, the second round of freezing rain will probably change to cold rain relatively quickly, and Weds morning will hopefully not be too bad.  Once you get into the Piedmont (west of I-95), it will be a different story... with heavy freezing rain lasting into the morning hours on Weds, perhaps changing to rain before ending mid day."

Posted by Frank Roylance at 12:28 PM | | Comments (3)
Categories: Forecasts
        

Next up ... an ice storm for northern counties

With an ice storm on deck for Tuesday, the National Weather Service has posted a Winter Storm Watch for the northern tier of Maryland counties, from Garrett in the west to Cecil in the east, and including Baltimore City.

The Watch begins late Monday night and continues through WEDNESDAY morning. As much as a quarter-inch of ice could accumulate Tuesday on branches and utility lines, meaning a risk for another round of power outages for a region that only emerged this weekend from the last round.

For the northern counties, the event is forecast to begin late Monday night with snow, sleet and freezing rain as temperatures rise overnight out of the mid-20s. That is expected to change over to all freezing rain Tuesday morning, continuing straight through until early Wednesday, when it will finally become just rain.

"A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS." - NWS

South of those counties - from Montgomery, Howard and Arundel south - the weather service is calling for a confection they're calling "a light wintry mix," including some freezing rain. We may AccuWeather.comsee them issue a Winter Weather Advisory later today to cover  some "light" ice accumulations. The precipitation would change to rain Tuesday afternoon.

The culprit is another storm system, this one now developing in the Plains. As it approaches, it will throw warmer, wetter air into the region from the southwest, That air will be forced up and over the very cold layer of air now resident east of the mountains - cold air damming.

The precip could begin as snow in the northern counties, but once it starts falling, whatever falls will gradually erode the cold air, changing to sleet and freezing rain. Forecasters give the counties near the Mason-Dixon Line the best chance to see freezing rain persist through the day Tuesday and into Wednesday morning.

The whole mess should pass by Wednesday afternoon. A Wednesday high of 47 degrees will give way behind the passing cold front to a resumption of below-average cold temperatures for the balance of the week, with highs in the low 30s.

Don't you just love winter? 

The good news is that this round of bad weather is actually the good side of this storm. Portions of the Central Plains and the Midwest are facing heavy snow, even blizzard conditions, this week as the Groundhog Day storm blows through. Here's AccuWeather.com's take.  Punxatawney Phil seems unlikely to see his shadow.

Posted by Frank Roylance at 6:43 AM | | Comments (8)
Categories: Forecasts
        

Big BGE bills at your door this month

Dave G. left a comment on this blog Sunday about his high BGE bill, just arrived at his home. He was actually responding to a post we wrote a year ago, when THAT January's bills were coming in BGE billafter a cold December - 2009.

I've picked up Dave's comment and I'm re-posting it here because I suspect a lot of people are choking on their own bills at the moment. So here's an opportunity to commiserate. 

Here's Dave query, and my response:

"What is the difference in degree days for December, 2010 and December 2011?  My usage was 55% higher this year than last. - Dave"

FR: Bill, I'll assume you meant Dec. 2009 and December 2010.  According to the NWS, the total degree-days in December 2009 was 929. That increased to 1,003 in December 2010. That's an increase of almost 8 percent.

I just checked by own bills, and my electric usage (heat pump & lights, etc.) increased 11.7 percent. My gas (furnace and water heater) consumption was up 13.6 percent.  During the same period, according to the bill, the average temperature was the same (32 degrees) both years. NWS/NOAA Temperatures Dec. 2009

Now, you do need to consider that your billing cycle probably doesn't match the calendar month of December, so you would not expect the average temperature during your cycle for those two months to track precisely with these HDD numbers for the calendar month. Mine, for example, runs from mid-December to mid-January. Plus, only about half of our annual utility bills arise from heating and cooling. 

Also, the number of degree days is based on daily average temperatures - the day's high, plus the low, divided by two. That may not reflect the number of hours we actually spent at or below 32 degrees, where heat pump auxilliary heat coils typically switch on. NWS/NOAA Temperatures December 2010

BGE released a statement  Jan. 21 noting that the hours below 32 degrees in November-December 2010 jumped 43 percent compared with the year before. They warned that bills would be high in this cycle as a result. For that full release, click here.

This last billing cycle may also have been a day or two longer than the same one a year ago. Mine was 34 days this time, 33 days last time. That adds one day of usage. And, you may have other usage issues, like relatives who won't leave and teenagers taking 30-minute showers.

All that being said, Dave's 55 percent usage increase would seem to be pretty high. Maybe it's time for an energy audit.

Posted by Frank Roylance at 12:01 AM | | Comments (14)
Categories: By the numbers
        

January 30, 2011

NWS: Groundhog Day storm will be an icy mix

Forecast models are predicting this week's "Groundhog Day" storm will track to our west, leaving Central Maryland on the "warm" side of the action. That means we should see no Snowpocalypse. But expect a nasty mix of precipitation. It begins Monday night with a chance of snow, but evolves with snow, sleet, freezing rain and cold rain before ending late on Wednesday.

Ick.

AccuWeather.comThe storm is forecast to develop east of the Rockies Monday, moving toward Texas and Louisiana before turning Tuesday toward the Ohio Valley.

Meanwhile, high pressure to our north will continue to hold a layer of cold air in place east of the Appalachians. Meteorologists call this "cold air damming." And that layer of cold air will provide the low temperatures - for a while - that will cause the precipitation that's headed our way to freeze when it lands. It's too thin to bring us snow - at least not for long.

The official forecast for BWI-Marshall calls for a chance of snow Monday night, with lows near 25 degrees. Snow and sleet chances are set at 40 percent for Tuesday morning. That will be followed by rain or frezing rain in the afternoon as more warm air slides into the region, flowing counter-clockwise around the low that will be tracking north along the Appalachians to our west. Daytime highs will hover just above the freezing mark.

The AccuWeather.com folks have us solidly in the icy mix corridor for this storm.NOAA/NWS

After midnight Wednesday morning, forecasters say we have an 80 percent chance of seeing all rain, with overnight lows at the surface still near freezing. The rain should begin to slack off by mid-afternoon, but forecasters continue with a 30 percent chance of showers into the evening. This event should wash away a good portion of the snow remaining from last Wednesday's storm.

The sun is due back Thursday and Friday, but temperatures will continue to run nearly 10 degrees colder than the norms for this time of year in Baltimore. (We've seen just eight days in January with temperatures averaging above the daily norms. Only seven days were above-average in December.)

The next chance for snow comes next Saturday. Models are hinting at a coastal low forming off the Carolinas. That will be the anniversary of the first of last February's back-to-back blizzards. You may remember them.

Posted by Frank Roylance at 8:59 AM | | Comments (2)
Categories: Forecasts
        

January ending, at last

FROM TODAY'S PRINT EDITIONS:

Why does January seem to drag so? No matter; we’re done with it tomorrow. In February, average highs climb from 42 degrees to 48 by month’s end. Average lows claw back from 24 degrees to 29. The record high is 83 degrees (!) on Feb. 25, 1930. But winter mostly retains its grip. Six of the 10 biggest snowstorms on record for Baltimore have struck between Feb. 5 and 19. Baltimore’s record low – minus-7 degrees - has been reached on two dates in February.

Posted by Frank Roylance at 12:01 AM | | Comments (2)
Categories: From the Sun's print edition
        

January 29, 2011

Moon and Venus paired in dawn sky

FROM TODAY'S PRINT EDITIONS:

Plan to be up early on Sunday? If skies are clear, look out a window that faces southeast for a nice view of Venus and a crescent moon. The moon will be just a few degrees below and to the left of Venus. They make a pretty pair on a cold winter morning. Venus will be sliding into slowly into the sunrise this spring as the planet rounds the rising sun. It will reappear in the west, from behind the setting sun, late in the fall.

Posted by Frank Roylance at 12:01 AM | | Comments (2)
Categories: From the Sun's print edition, Sky Notes
        

January 28, 2011

Wednesday's snowstorm seen from space

NASA has released some terrific images of Wednesday's Rush Hour Storm. There's a great still, (clickable) below, snapped at about 9:30 a.m. Thursday after the storm had passed, revealing the snowcover left behind. There's also a nifty animation. Click here for that.

Posted by Frank Roylance at 11:13 AM | | Comments (1)
Categories: Cool pictures
        

NWS: Today's "clipper" snow light, but slippery

The National Weather Service has extended a Special Weather Advisory to all of Central Maryland, noting that the "clipper" system moving across the region today could make road surfaces slippery:

"SNOWFALL WILL LIKELY START BY 10 AM IN WASHINGTON DC AND FREDERICK MARYLAND...AND BY 11 AM IN THE BALTIMORE AND ANNAPOLIS.

"SNOWFALL ACCUMULATIONS UP TO AN INCH ARE EXPECTED DURING THIS
TIME. SNOWFALL WILL MAKE UNTREATED ROADS SLIPPERY IN SPOTS CAUSING
DIFFICULT DRIVING CONDITIONS. PLEASE REMEMBER TO LEAVE PLENTY OF
DISTANCE BETWEEN OTHER VEHICLES AND ALLOW EXTRA TIME TO REACH YOUR
DESTINATION.

"TEMPERATURES WILL RISE ABOVE FREEZING LATER THIS AFTERNOON."

Here's the forecast for BWI-Marshall.

 

Posted by Frank Roylance at 9:54 AM | | Comments (2)
Categories: Forecasts
        

First "clipper" snow is falling

At 9 a.m. we're starting to see flakes on the WeatherDeck in Cockeysville, the first of what is still anticipated to be a minor brush with wintry precipitation today. The weather service is reminding Marylanders that even a little snow can become slippery. And Eric the Red sees a chance this will be a shade bigger than advertised.

Intellicast shows the snow really well on its radar image. It seems to be focused mainly across the northern tier of Maryland counties for now.

NOAAThis is not, or should not be a big deal. These clippers come out of the frigid northwest will little moisture compared with the storms, like Wednesday's, that are able to draw in moisture from the Gulf and the Atlantic.

The National Weather Service expects this one - the first of two this weekend - to drop no more than an inch before turning to a mix of rain and snow Friday afternoon. 

They have issued a reminder that even a little snow can be problematic for the unwary: "SNOWFALL WILL MAKE UNTREATED ROADS SLIPPERY IN SPOTS CAUSING DIFFICULT DRIVING CONDITIONS. PLEASE REMEMBER TO LEAVE PLENTY OF DISTANCE BETWEEN OTHER VEHICLES AND ALLOW EXTRA TIME TO REACH YOUR
DESTINATION
."

There's a slight (20 percent) chance of a second round between 10 a.m. and 2 p.m. Saturday.

Here's Eric the Red, a professional forecast from Baltimore, on the first round: "Expect a period of light to maybe even moderate snow for several hours during the late morning and early afternoon.  Up to an inch is possible as this system swings thru.  Should be done by the eve rush... or so I hope."

UPDATE,  9:45 a.m.: Eric the Red is now sensing more of an issue with this clipper. "Hmmm...  radar is getting very interesting.  Snow is increasing in intensity and coverage... so maybe I should up the ante a hair.  An inch of snow now seems likely... and some areas might get 2".  Still looks to be over before the eve rush.  Reports west of DC and Baltimore are coming in with light to moderate snow... visibilty down to 1/2 mile."

AccuWeather.com seems unimpressed by these clippers.

Forecasters continue to watch their models as they conjure up the next worrisome storm. It hasn't actually formed yet, but the models foresee it coming together by early next week. The storm track remains critical and unknown.

AccuWeather.com is no closer to figuring it out: "Whether or not the storm is able to make the entire run up the Atlantic Seaboard or slip out to sea halfway up is uncertain at this time. However, that path is critical for determining the heavy snow area in the mid-Atlantic and New England. At this point, we can say there is at least a chance of another snowstorm for part of the I-95 zone and others in the Northeast during the middle of next week."

Posted by Frank Roylance at 9:03 AM | | Comments (1)
Categories: Forecasts
        

The Sun's new print weather page arrives Sunday

The Sun's print subscribers will get a bonus with their Sunday papers this weekend as the paper  unveils a bigger, more colorful and informative weather feature.

As the newspaper continues to rebound from a long period of downsizing, it's now the weather page's turn for some upgrades and revitalization. Many of the changes have been made in response to reader requests and suggestions in recent months. Many thanks for your interest and your ideas. We have listened.

Here's some of what you'll find when you open your paper, beginning on Sunday:

Weather page* The feature will double in size, from the current quarter-page, to a half-page. We're also moving from page 3 to the back page of the Sports Section. Look for us there.

* We will be leaving the 1950s world of black-and-white behind, moving back to a full four-color display.

* Readers' most-requested feature, the national weather map, is back. It will show temperature patterns and the barometric highs and lows, cold fronts and warm fronts all across the Lower 48 states.

* A larger Maryland map will include high and low temperature forecasts for more cities and towns.

* We'll have an easier-to-navigate list of U.S. and foreign cities, with forecasts for today and tomorrow. We're also adding red indicators showing where travelers can expect travel delays. The section will also include the high and low extreme-temperature readings for the Lower 48 states, and the world.

* The Baltimore Almanac will include all the highs, lows and records for BWI-Marshall Airport. New "trend" graphics will also give readers a quick grasp of recent trends in precipitation and temperature.

* We are also adding easy-to grasp graphical representations (in season) forNational map pollen counts, UV and Air Quality Index readings.

* Plenty of readers also asked us to provide degree-day reports, so they can estimate how much energy they're using for heating and cooling. So we've added that, too, along with the long-term averages for comparison.

* We will continue to provide a Marine Forecast, with tide times for the Chesapeake and the beaches, wave heights and water temperatures.

* Stargazers will appreciate another new feature. In addition to the moon phases, and the rise and set times for the sun and moon, we will now be listing rise and set times for all five naked-eye planets, so they can see what they'll find in the night sky and when to look. 

* And, in addition to the five-day forecast from the WJZ First Warning Weather Team, our forecasts and reports will be backed by the power and reliability of AccuWeather. Finally, the new page will continue to be anchored, at the bottom, by me (with a smaller photo, thank heavens) and the Maryland Weather Blog.

So, if you are a subscriber, we thank you for your loyalty and patience. If you're not, we hope you will take another look at the paper and consider joining us. Tell us what you think of the print weather page improvements. And if you have any suggestions, we're always listening.

(SUN PHOTOS: Weather page mockups, Frank Roylance)

Posted by Frank Roylance at 7:54 AM | | Comments (3)
Categories: Notes to readers
        

Hate snow? Move to Bermuda

FROM TODAY'S PRINT EDITIONS:

BermudaJeffrey Brauner lives in snowy Baltimore, so he’s dreaming of Bermuda: “What’s the coldest it’s ever gotten in Bermuda, and the most snow they’ve had, if any?” Ah, Bermuda, the fabled Somers Isles, setting of Shakespeare’s “The Tempest.” While it lies on the same latitude as South Carolina, the island’s climate is moderated by the Atlantic. The coldest temperature on record there is 43.6 degrees, the warmest is 94. Hurricanes? Yes. Snow? Never.

Posted by Frank Roylance at 12:01 AM | | Comments (6)
Categories: From the Sun's print edition
        

January 27, 2011

Had enough yet? More snow on the way

Snow-weary Marylanders will not be able to put away their shovels and gloves just yet. There’s more wintry weather on the horizon. The National Weather Service is watching a pair of “clipper”-type storms that are expected to pass through Central Maryland in the next two days. And a more worrisome storm is due early next week.

Neither clipper will pack much moisture, so neither should drop more than an inch or so, forecasters said. And many of us may see little or nothing. Here's the forecast map for the first one.

The first is due after 9 a.m. Friday, with less than a half-inch of new accumulation likely. Snow chances were set at 40 percent. Most likely to be affected are communities on the western slopes of the Appalachians, and along the Mason-Dixon Line, forecasters said. AccuWeather.com

Snow showers are possible Friday evening, followed by the next little clipper system, Saturday morning. The same areas – the mountains and the state’s northern border — are most likely to see the flakes.

Of more concern to meteorologists is a more potent system the computers predict will menace the region by mid-week. AccuWeather.com is already calling it the Groundhog Day Storm. For the moment, Sterling is setting the snow chances for that one at 30 percent, starting Monday night and continuing  into Wednesday.

The models agree it will be a “significant” winter storm. But, five days out, they disagree on its path. A track to our south would bring us more snow. A track up the Ohio Valley would place us on the “warm” side of the circulation, leaving us with a decidedly cold menu of snow, sleet, freezing rain and plain rain.

Posted by Frank Roylance at 2:20 PM | | Comments (14)
Categories: Forecasts
        

Deadly Knickerbocker Storm struck 89 years ago

As punishing as Wednesday's Rush Hour Storm was for thousands of Maryland commuters, road and utility crews, nothing Marylanders have suffered in winter can compare with the 1922 Knickerbocker Storm that began 89 years ago today. It will always be remembered as the deadliest in the region's winter history.

Over three days, the storm piled up 24.7 inches in Baltimore, a mark that remained the local record until 2003. It began on a Friday evening, at rush hour. Commuters sought shelter in hotels and clubs, or remained trapped in their stranded streetcars.

Sun front pageThe late Walter Sondheim, Jr., was among the stranded that weekend. He told The Sun in a 1996 interview that he was 14 back then, trying to get home on Bolton Street.

"I was on a streetcar. It got stuck on Linden Avenue, a couple of blocks south of McMechen," he recalled. "I probably walked three to four blocks. I guess I slogged through the snow. I came home to a frantic mother."

Former Maryland Comptroller, the late Louis Goldstein was 9 that weekend, and he took the storm as an invitation to head for Patterson Park. "They had these big box sleighs at Patterson Park and Baltimore Street," he recalled in 1996. "People used to go over there, ride one of those sleighs down [a long hill] and walk all the way back [up], and that was some kind of walk. I could do it now."Baltimore Sun

The streetcar company called for sweepers and shovelers to clear their tracks. As many as 4,000 found work at $3.50 a day.

Kathryn Bradley recalled the storm in a Sun interview in 2003. She was 97, living at the Oak Crest Retirement Community. "We didn't think anything of it at the time," she insisted. "It was before the age of automobiles, and I do remember riding a buggy. Nobody cleaned the streets. The streets were just left the way they were. There wasn't that much traffic. I just envied anybody with a horse and sleigh. At least they could get around, when nobody could get around in a car. Cars weren't made for snow in those days."

As bad as it became in Baltimore, it was worse in Washington, which recorded 30 inches of heavy, wet snow. The burden proved too much for the roof of the capital's Knickerbocker Theater. It gave way during a Saturday evening movie show, and after the body counts were finally reconciled and made official, authorities said 98 people had been crushed to death. Another 135 were injured and more were trapped. The tragedy gave the storm its name.

Bill Bowles was 94 in 2003 when he spoke to The Sun at Oak Crest about the storm, which he experienced in Alexandria, Va. "The snow was so deep my brother and I dug tunnels through it and crawled around through and made a house under the snow," he said.

He remembered hearing of the theater disaster across the Potomac, and being amazed at the toll. "Why people were  watching a movie during a storm like that, I've never been able to figure out," he said.

Thanks to Sun Librarian Paul McCardell

Posted by Frank Roylance at 11:02 AM | | Comments (1)
Categories: History
        

Rush Hour Storm drops up to 11 inches

It would have been hard to design a storm better suited to slam the region during both rush hours on Wednesday. After a surprise couple of inches in the morning delivered an uppercut to commuters making their way to work before daybreak, the back end of the same system swung a hard right to the chin in time for the evening rush.

The result was commuter purgatory. Emails from colleagues stuck on the JFX for hours, or on clogged city streets, encouraged us stragglers in the newsroom to find hotel rooms. I've just made it home after a night with nothing but a warm bed, dirty clothes and a hotel toothbrush.NOAA/NWS

For the record, city streets - at least the main routes downtown - were scraped and salted to mostly wet pavement by 6:30 a.m. The JFX was just wet, although the shoulders were lined with abandoned cars. The Beltway and I-83 north were just wet. York Road by 7 a.m. was still rough, with lots of packed snow and ice.

Our local streets were plowed but snow-covered. I got in just fine, except for the plow-plug where my car was supposed to go. I'd post a photo, but my camera is still back in the newsroom.

But enough about me. Below are some snow totals from the CoCoRaHS Network. Damascus takes the brass ring on that list this morning, with 12.3 inches. The official total at BWI-Marshall Airport was 7.8 inches through midnight. That brings the season's total to 12.1 inches, just a half-foot shy of the seasonal average for Baltimore.

And click here for the snow tally and snow map from the National Weather Service in Sterling, Va. Winfield, in Carroll County, would seem to have the lead there, at 12 inches

Elkridge, Howard Co,:  11 inchesNWS/NOAA

Catonsville, Baltimore Co.:  9.5 inches

Kingsville, Baltimore Co.:  9.4 inches

Silver Spring, Montgomery:  9.3 inches

The WeatherDeck in Cockeysville:  9.0 inches 

Frederick:  9.0 inches

Cumberland, Allegany:  9.0 inches

Mt. Airy, Carroll:  8 inches

Jarrettsville, Harford;  6 inches

Deale, Anne Arundel:  3.5 inches

Posted by Frank Roylance at 8:07 AM | | Comments (8)
Categories: Winter weather
        

A bone-dry morning in Freeland ?

FROM TODAY'S PRINT EDITIONS:

Bitter coldJohn Fausto writes from Freeland: “One day last week I woke up and … saw that the humidity was 4% and the temperature was 11 degrees …Could this be possible, as it would indicate a very dry (desert) condition.”  That’s one bone-dry martini. Those numbers suggest a dew point of 50-below zero. Maybe you were dreaming. Or your bleary eyes missed a digit alongside the 4. Or maybe your instrument was set to read out the “dew point” in degrees, instead of “relative humidity”  in percent.

(AP PHOTO: Jim Rider, South Bend, Ind. Tribune, 2009)

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: From the Sun's print edition
        

January 26, 2011

Heavy snow still due, forecast changed to 6-10"

Forecasters out at Sterling say the coastal low is deepening as predicted and some heavy snow and lightning was occurring closer to the storm's center. But they have trimmed their estimates of total accumulations for the Winter Storm Warning area in Central Maryland tonight back to 4 to 8 inches.

UPDATE 7 p.m. That National Weather Service is now calling for 6-10 inches for Carroll, Frederick, Harford, Howard, Montgomery, Northern Baltimore and Southern Baltimore. Forecasters are adjusting their estimates as radar shows evidence of mesoscale banding - very intense snow bands - crossing the region.

UPDATE, 5 p.m.: The NWS has trimmed its forecasts for Baltimore again, this time to 3 to 6 inches. At the same time, forecasters said, "THE HEAVY SNOW WILL REDUCE VISIBILITIES BELOW A QUARTER MILE WITH SNOWFALL ACCUMULATION RATES AT TIMES OF 2 INCHES PER HOUR. THIS
WILL PRODUCE DANGEROUS TRAVEL CONDITIONS DURING RUSH HOUR
."

"Recent spotter reports indicate  2-inch per hour snow, so accumulations reasonable even though peak period may not be much more than 6 to 8 hours long," forecasters said in their afternoon discussion. "Expecting a rather quick end to snow tonight .... That should be a couple of hours on either side of midnight, earlier southwest and later for NE Maryland."

 

Here's a look at where the snow was (blue) on radar around 4 p.m. (Click to enlarge.)

The storm's center was located near Norfolk this afternoon. A rapidly falling barometer in Baltimore was an indicator of the low's intensification as it reached the coast. Reports of lightning near the central low also indicated a very energetic storm. 

Other signs suggested to forecasters that "if any precipitation begins as rainfall, which may happen east of I-95, it'll change over fairly quickly to snow. The upper level energy transitioning off the coast at the moment, and rapid cyclogenisis should be underway through [7 p.m.] and beyond."

The Maryland Department of Transportation's CHART traffic cameras showed slushy, snowy conditions on the interstates north and west of Baltimore after 5 p.m.  

Baltimore barometer

Posted by Frank Roylance at 3:26 PM | | Comments (24)
Categories: Forecasts
        

Storm Warning expanded, 5 to 10" expected

Just as we began to get comments here from readers who, watching their thermometers climb, have been calculating that the snow storm is over, the National Weather Service has just upped the predicted snow totals to 5-to-10 inches and expanded the Winter Storm Warning to include most of the state.

AccuWeather.comLet us say this one more time. This morning's snow was a prologue. An overture. An appetizer.

The Southern low that is driving this sprawling event is still expected to reach the coast and intensify, dropping temperatures across the region and triggering a new, more intense round of snowfall later this afternoon, and continuing into the night. 

The Winter Storm Warnings now encompass all Maryland counties from Garrett to Prince Georges and Arundel, and the Upper Eastern Shore. They're all calling for 5 to 10 inches of snow before it all ends overnight. Only Southern Maryland and the Lower Shore remain under Winter Weather Advisories (less than 5 inches).

Here's the forecast discussion from Sterling: "THE SECOND WAVE OF THIS STRENGTHENING STORM SYSTEM WILL BE THE MAIN CONCERN FOR THE MID ATLANTIC REGION. UPPER LOW IN WESTERN NORTH CAROLINA/VIRGINIA AT THE MOMENT. THUNDER HAS BEEN NOTED IN THE VICINITY OF THEAccuWeather.com LOW ... INDICATING ENERGY INVOLVED.

"THE UPPER LOW WILL JUMP TO THE COAST BY LATE AFTERNOON AND UNDERGO
SIGNIFICANT INTENSIFICATION THIS EVNG. THE DYNAMIC COOLING WILL SUPPORT
MAINLY SNOW...EVEN IF SURFACE CONDITIONS MILD. THEREFORE PRECIP SHUD START AS
RAIN DC SOUTHEAST ...BUT CHANGE OVER QUICKLY. EXPECT BAND OF HEAVIER SNOWFALL...

"THE HEAVIER BANDS WILL BE PUSHING INTO THE I-95 CORRIDOR AND OVER
THE BAY NEAR MIDNIGHT. SNOW WILL END FAIRLY QUICKLY ALONG THE WESTERN EDGE
INTO THE EARLY MORNING HRS...AND BY 3-5AM THE LAST PORTION OF THE
BAND WILL BE ENDING OVER THE MD BAY...SLIDING EASTWARD OVER DELMARVA
AND TOWARD SOUTHERN NEW ENGLAND."

So far, the storm has dropped the most snow on the northern counties - especially Harford and Baltimore. Kingsville, in Harford County, reported 4 inches. Here are more totals from the CoCoRaHS Network.

Posted by Frank Roylance at 11:48 AM | | Comments (20)
Categories: Forecasts
        

"Cold air wedge" blamed for surprise accumulations

While the forecast did call for snow and/or rain in the early morning hours, I don't think anyone was quite prepared for the accumulations - up to 3 inches in some spots - that we woke up to this morning.

Prof. Jeff Halverson, at the University of Maryland Baltimore County, has offered an explanation. It's called a "cold air damming" - a wedge of cold, dense air that had settled in hung east of the mountains despite advancing warm, wet air from the South, and wouldn't let go. It was enough to make more of the predicted overnight precipitation fall as snow:

"[T]hat became entrenched east of the Blue Ridge overnight, and this kept the morning precip falling as a frozen mixture.  "The Wedge" is notoriously hard to predict.  The warm air push from the south was not strong enough to scour out this dense air mass.

From here, he says, "Expect a quick, hard hit of heavy precip returning around 1 pm through about 9-10 pm tonight, then a quick cutoff.  Most forecasters are predicting 4"-8" but there will be embedded bands that are very narrow, and extremely hard to predict more than 1-2 hours in advance where these will set up.  These are the "thundersnow" corridors

"Timing will be ugly - visibility could drop to near zero in the heart of the evening rush, not so much from wind-blown snow, but big flakes falling at 1"-3"/hour.  Interestingly, the [NWS meso-scale model] is predicting a narrow swath of heavy ice accumulation just north of  the I-95 corridor and mainly rain along and east of I-95. If you buy this model, the heavy snow stays across our far west and north burbs."

Here's the official forecast for BWI-Marshall from Sterling. Here's the Winter Storm Warning, posted for the northern and western counties.

Posted by Frank Roylance at 10:58 AM | | Comments (3)
Categories: Winter weather
        

Why weren't the roads pre-treated?

Can we agree that the main arteries - I-95 and Beltway for example - were a mess early this morning? I think we can. There have been numerous accidents, and lane reductions according to the traffic reports.

So why is it, after the SHA did such a great job pre-treating for previous little snowfalls this winter, that SUN PHOTO Snowthey opted out this time? Here's what The Sun is reporting this morning:

"The State Highway Administration did not pre-treat the roads because "all the forecasts were saying this was going to start as a rain event," said spokeswoman Kim Frum. "That would have been a huge waste of resources."

"However, crews were mobilized between 3 a.m. and 4 a.m., anticipating a need to address conditions on bridges, which freeze first, she said. As a result, they were able to quickly clean up primary roads, according to Frum.

"By 4:30 a.m., most of the main lines were just wet," she said."

Just wet? Really? Any morning commuters out there want to share their experiences from this morning's "rush" hour?

I can't say which forecasters the SHA folks were listening to. But, for the record, the National Weather Service had been predicting overnight "snow and rain" for days before the flakes actually began to fall.

Granted, they always expressed it in terms of "snow or rain," or "snow and rain." On Monday they were talking about the storm being primarily a rain event, at least during the day Wednesday. But the forecast always called for at least some snow overnight. And by Tuesday afternoon this was shaping up as a significant storm. Winter Storm Watches were up for almost the entire state. The start times fell after daybreak, but wouldn't that be reason to get the roads ready? 

So where were the trucks? 

Posted by Frank Roylance at 8:40 AM | | Comments (29)
Categories: Winter weather
        

Morning woes just the appetizer; 4-8" due

A couple of inches of snow before dawn was enough to slick the roads in most of the region, close most schools and snarl the morning commute. But the main event is still not scheduled to get underway until this afternoon.

Forecasters are predicting 4 to 8 inches north and west of the I-95 corridor, with only a bit less to the south and east, including the Upper Shore. Western Maryand  - Garrett, Allegany and Washington counties- could see 6 to 10 inches. Bel Air was already reporting 3.5 inches this morning on the CoCoRaHS Network. There was 2.8 inches on the WeatherDeck in Cockeysville at 8 a.m. What does your yardstick say?

The National Weather Service has posted Winter Storm Warnings for Frederick. Montgomery, Carroll, Baltimore (city and county), Harford, Cecil, the northern Shore and the western counties. AccuWeather.comThe Warnings call for "moderate" snow to begin falling this afternoon after mixing with the morning's "light" snow and rain.

The snowfall is expected to become heavier late in the afternoon, and will be at its most intense between 4 p.m. and midnight. Commuters? Are you paying attention?

South of the Warning zone, Sterling has put Winter Weather Advisories in place. There, the morning snow will mix with more sleet and rain before switching back to all snow in the afternoon, holding projected accumulations to just 3 to 5 inches - below the Warning criteria of 5 inches.

All told, what we're looking at here is the most - the only - significant snowfall of the season so far for Central Maryland. The two-part event has begun with an inflow of relatively warm and wet air from the Gulf and the Atlantic as it is swept north by a Southern low in Georgia. It's encountering cold-enough air in place here to trigger the snow. Temperatures will rise above freezing as the morning wears on, creating a wetter mix, and rain, especially closer to the coast.

By late morning it may seem like the storm has worn itself out. But as the Southern low makes its way up the coast it's forecast to intensify. Heavier precipitation will move into the region from west to east, and by late afternoon, winds will shirt to the north northwest, temperatures will drop. The mixed precipitation will change over to snow and start to pile up quickly. Here's a bit from the NWS morning forecast discussion: 

"...A SOLID CHANGEOVER TO SNOW IS EXPECTED AND ACCUMULATION WOULD LIKELY BEGIN IN EARNEST. SIMILARLY INTO THE EARLY-MID AFTERNOON THE LEE OF THE BLUE RIDGE AND FOOTHILLS...AS WELL AS NORTHERN MD...WILL SEE THE CHANGEOVER TO ALL SNOW AND ACCUMULATIONS THEREAFTER. FOR THE PIEDMONT AND DC/BALT METRO AREAS...MID-LATE AFTERNOON W/ POSSIBLY A FEW MORE DEGREES TO OVERCOME IN TERMS OF GETTING BACKSnow on the WeatherDeck
BELOW FREEZING. FOR LOWER SOUTHERN MD AND AREAS SE OF THE METRO
AREAS...JUST IN THE LATE AFTERNOON/EARLY EVE
."

Eric the Red is a little more aggressive than Sterling with total accumulations: "Considering what greeted me this morning, think it may be wise to up the totals a hair in the Piedmont... and go 6-12" across the colder locales north and west of Baltimore and DC.  The coastal low has produced more snow than I thought, altho the precip is falling as rain just east of I-95. ... 

"Once the heavy precip arrives early in the afternoon, the real fun should start.  Any precip that is not snow will change to snow, and it will be heavy.  Still foresee snowfall rates as high as 2" or more an hour hammering the afternoon rush. ...  I would strongly advise you plan to be home by 1 pm or be willing to drive in very heavy snow, because it will arrive quite suddenly. Totals... Along and east of I-95: 4-8" (I'm wondering if even in these locales this might be low) Colder burbs north and west (Piedmont): 6-12"

AccuWeather.com's Alex Sosnowski warns against taking the mid-day lull in the storm as an all-clear: "The rain and wintry mix in the Washington/Baltimore to Philadelphia/New York City slot [during the day...] will have many people think the storm is a bust. After a relatively small amount of snow and slush in these cities on south and east, it may seem like the storm has slipped by." But the storm will turn colder as it strengthens off the New England Coast, he said, allowing the majority of snow to accumulate in the major Northeast cities.

And, Foot's Forecast: "We do expect a change over to rain for areas around Baltimore, but areas N&W could stay all snow. If it stays all snow totals will be higher. We will see a break in the action after noon before the second round of precip comes in tonight with heavy snow for most of the area. We still are calling for a general 5-8" for the entire Central MD region (Ending Thursday-2am)."

(SUN PHOTO: Frank Roylance, Snow on the WeatherDeck this morning)

Posted by Frank Roylance at 6:49 AM | | Comments (6)
Categories: Forecasts
        

January 25, 2011

Storm Watch now posted for all but southern Shore

The National Weather Service has extended the Winter Storm Watch to all of Maryland except for the Lower Eastern Shore, with the possibility for 5 inches of snow or more. Garrett County, in far Western Maryland, could see 6 or more.

The National Weather Service has nudged its predictions upward again, and Eric the Red is looking for 4 to 10 inches ... and a chance for thundersnow! And now BGE is warning customers to prepare for power outages as heavy, wet snow threatens to bring down limbs and power lines.

UPDATE, 6 p.m.: The weather service has issued a Winter Storm Warning for Allegany and Washington counties, with 4 to 8 inches of snow expected by Wednesday evening. The snow there is expected to start just after sunrise Wednesday.  The Warning replaces the Watch issued earlier.

The predictions on the new snow forecast map out of Sterling have also been bumped upward again by the computers, forecasting 7 inches north and west of Baltimore and Washington. (You can now click on the map for a pop-up version. You CAN teach an old dog new tricks!)

Earlier today, the Watch included only the western counties, plus Frederick, Montgomery, Carroll, northern Baltimore and Harford counties. Now Baltimore City and points south are included. Washington, D.C. and Northern Virginia are under a similar watch.

The Watch is in effect from Wednesday afternoon until late Wednesday night. The storm is still expected to bring a mix of wintry precipitation, with intervals of snow, rain, sleet and freezing rain during the day. But it's expected to end with a snowy flourish around Baltimore beginning in the late afternoon and evening.

Here's how Eric the Red is putting it this afternoon: "...the potential for a period of very heavy snow just in time for the eve commute. This looks like a wet snow... which may keep accumulations down... but I think it's time to go 4 to 10" in the metro area and points west and north... I should note that it would be very, very wise to think about getting home early tomorrow.

"I can not stress how intense the snowfall rates may be during the pm commute. If the models are right, and you go with a conservative solution ... then you're staring at 1 to 3" per hour for 4 to 8 hours. The precip will start to flare up ~ 1 pm or so."

Posted by Frank Roylance at 1:13 PM | | Comments (16)
Categories: Watches and warnings
        

Winter Storm Watch posted north of Baltimore

NOAA/NWSThe National Weather Service has posted a Winter Storm Watch through late Wednesday night for communities north of Baltimore - including Frederick, Carroll, northern Baltimore and Harford counties.

Montgomery County and those west to Allegany County are also in a Winter Storm Watch now.

And the NWS snow forecast map (left) has been beefed up some, too, now. (Is this starting to feel like the accumulation estimate escalation we saw so much last winter?) For a better look at the map, click here.

The Watch calls for 5 inches of snow or more, amid a mix of snow, sleet, freezing rain and rain. The precipitation would begin in the late afternoon Wednesday in Baltimore's suburbs, changing to snow as temperatures drop into the upper 20s Wednesday night.

 A Winter Storm Watch means there is a potential for significant snow, sleet or ice accumulations that may impact travel. Forecasters urge those in the Watch area to monitor the latest forecasts.

Posted by Frank Roylance at 10:41 AM | | Comments (21)
Categories: Watches and warnings
        

OK, so maybe we get a few inches of snow

The pendulum appears to be swinging back toward a snowier outcome for the winter storm forecast for the mid-Atlantic states Wednesday.

The National Weather Service is now predicting minor accumulations for BWI Marshall, as forecast models finally begin to converge on a common solution that would increase the chances for some accumulation as the storm departs.

NOAA/NWSThe official BWI forecast calls for a 50 percent chance of snow and rain, beginning after midnight Wednesday morning. Any snow before 9 a.m. would gradually change to rain and snow, or all rain during the day Wednesday. But the forecast now has the precipitation switching to all snow after 9 p.m. Wednesday. Temperatures will fall into the upper 20s.

The snow forecast map shows as much as 4 inches piling up in northern parts of Carroll, Baltimore and Harford counties, fading to 2 or 3 inches in the closer Baltimore suburbs, and less as you move south and east. The morning forecast discussion from Sterling gives you a sense of how complex this event will be.

AccuWeather.com now has Central Maryland firmly in the snow bands of its snow map, too. The "wintry mix" would be confined to Southern Maryland and the Eastern Shore. The 1-to-3 band lies just south and east of Baltimore; the 3-to-6 band is just north and west.

Three to six inches are possible for western Maryland, too, by their reckoning. Six to 12 are possible in some mountain counties of Maryland and West Virginia. The biggest hit from this storm would land on Massachusetts, with 12 to 16 inches possible there. Once the storm passes by, they're expecting another surge of cold Canadian air next week.

Eric the Red has the snowiest solution this morning:  "A burst of moderate to heavy snow Weds eve.  The timing of the changeover will be critical to the final snow tally; obviously, the sooner it changes over to snow, the more snow you'll get.  Well Duh.  But pinpointing when that will occur is the tricky part.  I like the 4-8" range I mentioned yesterday.. but this could be lower if the precip stays rain/sleet longer, and be higher if it stays mostly snow." 

Unconvinced? Here's another contribution, from Jeff Halverson, associate professor of geography and environmental systems, at UMBC's Joint Center for Earth Systems Technology. On the jump: 

 

"Part 1, the coastal low coming up from the south, will bring bring a period of light-moderate rain during the day tomorrow, with the heavy corridor of moisture staying east of the metro region. 

"Part 2 is an upper level disturbance - a combination of energy (spin) and deep cold air - that will sweep in from the Ohio Valley and merge with the back-side of the exiting coastal low.  Part 2 will impact the region late Wed into Wed night.  

"The cold air will change precip over to snow, and the energy is such that moderate to heavy snowbands could create a 6-hour burst of significant snowfall across the metro areas.  Totals could range from 4"-6", but accumulation will be initially reduced by standing water on roads, and any pre-treatment that is put down. 

"Eventually, though, the rate of snowfall and cold air moving in should cause snow to stick.  Could be a messy Thurs AM rush."

Posted by Frank Roylance at 8:03 AM | | Comments (3)
Categories: Forecasts
        

January 24, 2011

Sunny Tuesday, then a rainy mix Wednesday

Pity the poor weather forecasters. This storm continues to vex them, just as those that have come before this winter have done.

Officially, they're calling for rain and snow at BWI-Marshall, beginning after midnight Wednesday morning, becoming all rain after noon as temperatures rise from the freezing mark to the upper 30s. Snow may mix back in after dark, changing to all snow after midnight Thursday morning. 

But even just 36 hours out, forecasters are still puzzling over exactly where the storm will go, exactly who will get rain, who will get snow, and where the slop between will fall. And the computer models still can't give them consistent answers.Cold January rain Baltimore

The storm itself is gathering on the Gulf Coast tonight, sweeping up plenty of moisture to send north and east, along with milder temperatures.

"Unfortunately, the model guidance starts to diverge through this time frame," forecasters admit in this afternoon's forecast discussion from Sterling. "That places significant uncertainty in system evolution, during a winter season where that seems to be the norm."

A 42-degree high on Tuesday, followed by increasing cloud cover to put a sort of blanket over the region - holding in some of the daytime solar heating, would seem to argue against overnight temperatures cold enough to sustain "a big snowstorm," they reason.

So they lean toward a rain/snow mix beginning around dawn Wednesday. And not a lot of precipitation at that, despite the storm's Gulf origins.

They're talking about rain to the south and east, snow to the north and west, and a mix in between. At the same time, they confess, "[We] have low confidence on who will get what ...Maximum temperatures Wednesday should be above freezing most areas, which would cut [snow-to-water] ratios and make accumulations more problematic anyway."

Bottom line here: Take an umbrella. Wear sensible shoes.

What's everyone else saying?

Foot's Forecast still deals with the uncertainty by laying out a range of possibilities. And they still like Scenario A: "Some snow would be possible for areas west of I-95 in western Maryland and western Virginia. Areas from Southern Maryland to the upper Eastern Shore would have a mix of rain and snow or just rain, with all rain for the Atlantic beaches. Liquid precipitation totals for the I-95 corridor could exceed one inch in some places, however light snowfall amounts would be confined to a possible changeover to snow on the backside of the system."

Eric the Red, a professional forecaster from Baltimore offers: "My best guess: Snow and sleet will arrive in the predawn hours on Weds, and changeover to mixed precip or cold rain along the I-95 corridor, AccuWeather.comwhile moderate to heavy snow falls farther west.  As the day progresses, precip will change back to all snow from west to east, with some accumulations likely. Precip will taper off Weds night.  This does not look like a whopper, but will nevertheless have enough precip with it that snow totals - if the pcp stays all snow - would tally 4 to 8".  But before you start thinking about the impending 4-8" snowfall, know that the odds are stacked against this thing staying all snow."

And here's AccuWeather.com: "There are several factors influencing this storm, mostly that weigh in against heavy snow in the major I-95 cities from New York southward through Washington/Baltimore. However, some areas inland of the coast will get clobbered with snow from the storm."

Their rain/slop/snow map (above) shows a tightly banded stretch right through Central Maryland. Easy to see there why such a small shift in storm tracks could make a big difference in what happens here.

My bet? A very cold, rainy day for Baltimore on Wednesday, with lots of slush to the north and west.

(SUN PHOTO: Amy Davis, January 1994)

Posted by Frank Roylance at 4:29 PM | | Comments (3)
Categories: Forecasts
        

Maryland Weather Blog rated among the best

The Maryland Weather Blog has been rated among the 49 best meteorology blogs on the Internet by yet another blog - Engineering Degrees Online.

Maryland Weather blogWe are listed as seventh in the "Local and National Meteorology Blogs" category.  Not sure if the ordering has any meaning. (Maybe there ARE only 49 weather blogs.) But hey, we're happy to get noticed. If nothing else, it's a handy guide to some of the other weather blogs out there.

The Maryland Weather Blog has been up and running since September 2004, the Baltimore Sun's first online blog. We frequently rank among the most-visited in The Sun's roster of 39 blogs. Last week we recorded more than 106,000 page views, second only to Ravens Insider and Orioles Insider blogs. More than half of those hits were local.

The Sun continues to work to improve the weather information we provide to readers. Next Sunday we plan to debut our new, half-page, four-color print weather feature. We'll have more here later in the week about what new information you'll find there. 

Thanks for reading The Sun, in print and online.

Posted by Frank Roylance at 2:20 PM | | Comments (11)
Categories: Notes to readers
        

Official forecast leans to rain, changing to snow

National Weather Service forecasters out at Sterling seem to be moving toward  a more confident prediction for this week's winter storm. They're talking about a largely rain event for the I-95 corridor, but one that will likely see some changeovers to wet snow, with a snowy finish.

It's not all in the bag yet. There remains some considerable uncertainty about the precise storm track. And, as usual, only a small movement in the rain/slop/snow line could make all the difference for the densely populated I-95 corridor.

The official forecast for BWI-Marshall Airport calls for a 40 percent chance of rain or snowNWS beginning after midnight Wednesday morning. That would become all rain after noon on Wednesday, with daytime highs in the upper 30s. Rain and snow chances remain at 60 percent into Wednesday night, changing to all snow after midnight. Overnight temperatures  would drop into the upper 20s.

The action here is centered on a storm dropping out of the Rockies and developing on the Texas Gulf coast today. It will move east, gathering up lots of Gulf moisture and sending it north and east into the Southeast and mid-Atlantic states. Delays in that movement are expected to allow the arctic high-pressure system that's been making us so cold this weekend to move out of the way, moving our temperatures to moderate before the rain from the South gets here.

After that initial rain on Wednesday, NWS forecasters said: "THE SECOND PORTION OF THE SYSTEM...MOVES UP FROM THE SOUTHERN APPALACHIANS AND UP ACROSS THE CAROLINAS AND OFF THE VA TIDEWATER. AROUND THE BACKSIDE OF THE UPPER LOW WOULD BE DECENT
COVERAGE OF PRECIP AND W/ THE COLD AIR WRAPPED AROUND THE UPPER LOW
- BETTER CHANCES FOR WINTRY PRECIP /MAINLY SNOW/ ACROSS THE AREA
AccuWeather.comBEFORE THE FEATURE DRIFTS OFF THE COAST LATE WED NIGHT
."

AccuWeather.com's Brian Edwards this morning notes the potential for a significant snowstorm here if the storm tracks just right, but then concedes that is now less likely:

"A track just off the coast would bring the heaviest snow to the I-95 cities and the beaches, as we have seen before, thus sparing the Appalachians the worst ... It seems less likely at this point for a major snowstorm along the I-95 corridor from Washington, D.C., to Philadelphia and New York City and along the Eastern Seaboard Tuesday night through Wednesday night.

"The brutal arctic cold that has been in place will be eroded on Tuesday as an area of high pressure retreats and a southeasterly flow off of the Atlantic Ocean pulls in milder air."

Foot's Forecast offers four scenarios this morning, but favors Scenario A: "The storm tracks along the coast Wednesday, bringing a mixture of rain and snow for the immediate I-95 corridor from Washington, D.C. to Philadelphia. Some snow would be possible for areas west of I-95 in western Maryland and western Virginia. Areas from Southern Maryland to the upper Eastern Shore would have a mix of rain and snow or just rain, with all rain for the Atlantic beaches. Liquid Precipitation totals for the I-95 corridor could exceed one inch in some places, however light snowfall amounts would be confined to a possible changeover to snow on the backside of the system."

We'll see. In the meantime, we are emerging from another very cold night on the WeatherDeck in Cockeysville, with a morning low at dawn today of 2 degrees. It's 7 degrees as I write this at 9 a.m.

BWI-Marshall reported a low of 8 degrees around 7 a.m. today. The record low for the date is 1 degree, recorded in 1963. The low at The Baltimore Sun's weather station, Calvert and Centre streets, was 16.7 degrees. Here (on the jump) are some other 7 a.m. readings from around the area. Feel free to report your lows in a comment.

Maryland Science Center:  17 degreesNOAA/NWS 7 a.m. temps.

Reagan National: 18 degrees

Dulles International:  6 degrees

Annapolis:  18 degrees

Martin State Airport:  12 degrees

College Park:  12 degrees

Westminster:  9 degrees

Hagerstown:  8 degrees

Cumberland:  7 degrees

Oakland:  9 degrees

Salisbury:  9 degrees

Ocean City:  13 degrees.

Posted by Frank Roylance at 8:44 AM | | Comments (8)
Categories: Forecasts
        

January 23, 2011

ISS leads sky tour over B'more Monday morning

Are you going to be up early Monday morning? If so, take a few minutes and step outside  for a look at the International Space Station as it makes a pass high over Baltimore.

If skies are clear, this one will lead the observer on a neat little tour of the early morning sky.

First thing you'll notice when you get outside is the planet Venus, the brilliant star-like object in NASA/ISSthe southeastern sky. It has been dazzling early risers for a couple of months now.

The waning moon will be hanging in the southwest. Watch in that general area at 6:14 a.m. as the ISS climbs up from the horizon. If the sun angles are right, its reflected sunlight will make it look like a bright star, moving quickly into the sky. If it's blinking or has colored lights, that's an airplane. Keep looking.

The station will pass almost directly in front of the moon, and then just to the right of Saturn. By 6:17 it will pass very close to a bright star called Arcturus in the constellation Bootes, near the zenith - straight up.

From there the ISS will move off to the northeast, passing close to another bright star called Altair, in the Summer Triangle, and through the nearby constellation Cygnus, the swan. That region of the night sky may be washed out by the gathering dawn.

By then the station and its crew of six, traveling at 17,500 mph, will have passed over Cape Cod and Nova Scotia before disappearing from our view at 6:20.

Posted by Frank Roylance at 12:03 PM | | Comments (3)
Categories: Sky Watching
        

Forecasters add "rain" to snow chances Tues/Weds

There remains a lot of uncertainty about the winter storm that seems to be headed our way for Tuesday and Wednesday. But National Weather Service forecasters out at Sterling have looked at the models and decided to increase the chances that some, or much of whatever we get in Central Maryland will be rain.

AccuWeather.comThe AccuWeather.com snow map today (left) also seems to have edged the "mix" component a bit closer - maybe right over - the Baltimore area. Bottom line appears to be that we are going to have to wait another day or so before the picture begins to focus. 

The official BWI-Marshall forecast from Sterling calls for  "a chance of rain and snow" beginning sometime after 1 p.m. Tuesday. The afternoon high is predicted to reach 39 degrees. That' still a bit cold for this time of year, but would clearly seem to favor rain over snow. The surface temperatures would remain above freezing right through Tuesday night and Wednesday, if the forecast holds up.

The trend - at least in Sterling - seems to suggest they are siding with an analysis that would move the storm track more to the north and west, allowing more warm Gulf and Atlantic air into the region to erode the deep cold we've been dealing with this weekend.

On the other hand, the morning forecast discussion from Sterling suggests plenty of lingering doubt, and not just about the temperature: "... MY CONFIDENCE IS STILL NOT THAT HIGH THAT ANY PRECIPITATION WILL OCCUR DURING THE DAY TUES."

Sterling has acknowledged the uncertainties that remain in the various supercomputer forecast models about just where this storm will go:

"AS OF TONIGHT...NOTHING HAS CHANGED. LOOKING AT THE SURFACE LOW-PRESSURE POSITION OF THE 3 MAJOR MODELS AT 12Z [7 a.m.] WED - NAM [MODEL] SHOWS IT OVER RDU [RALEIGH-DURHAM] ...ECMWF NEAR HAT [HATTERAS]...AND GFS LAGGING SOUTHWARD TO ATL [ATLANTA]. TO ADD TO THE CONFUSION THE SREF HAS THE LOW EAST OF ACY [ATLANTIC CITY].

"FOR TUES NIGHT WE HAVE CHANCE OF SOUTH WESTERN 3/4 OF THE CWA [FORECAST AREA] W/ LIKELY RAIN/SNOW FROM I-95 EAST...THEN CHANCE RAIN/SNOW SOUTHEAST OF THE MOUNTAINS MAJORITY OF THE AREA DURING WED. GIVEN THE WIDE MODEL DISPARITY THAT SEEMS LIKE A REASONABLE PLAN OF ATTACK...

"BUT CONFIDENCE REMAINS *LOW* W/ THIS SYSTEM. MODELS HAVE HAD GREAT DIFFICULTY W/ COASTAL STORMS THIS SEASON...AND UNFORTUNATELY THIS ONE MAY HAVE THE GREATEST MODEL DIVERGENCE OF ALL.. SO WE`LL ALL WAIT AND SEE HOW THIS STORM DEVELOPS AND MAKE ACCORDING CHANGES TO THE FORECAST. STAY TUNED."

Here's AccuWeather.com's take on the storm. Still pretty aggressive on the storm's power, but hedging its bets on what will happen in the I-95 cities.  Foot's Forecast is sticking with two possible scenarios - one bringing us lots of cold rain; the other several inches of snow.NOAA/NWS

UPDATE 5:40 p.m.: Eric the Red has checked in with his assessment. The storm is slowing down, and that may move sigificant snow off the table. Here's Eric:

"The storm is slowing down, which in turn is allowing the high to our north time to slip offshore.  Not good.  As a result, we lose the mechanism to lock in the cold air... and really become totally at the mercy of the final storm track when it comes to getting any snow. 

"To make matters worse, the models are all over the place.  In short, we still have a shot at a signficant East Coast storm.  But the storm has slowed down, which ... which takes [our] snow chances down a notch.  The target period is now Weds into Weds night."

Like the nice man said, stay tuned. In the meantime, we have had another cold night, but not as cold as Friday/Saturday at 6 a.m. We did fall to a low of 5 degrees here at 6 a.m. on The WeatherDeck in Cockeysville. Between 9 and 10 a.m., the mercury jumped from 9 degrees to 21 degrees.

The overnight low of 13 degrees at BWI-Marshall was nowhere near the record of 0 degrees for a Jan. 23, set in 1936. The record for Jan. 22 was minus-7 degrees, set in 1984. The 6 a.m. readings elsewhere around the region (not necessarily the lows for the night) looked like this:

BWI-Marshall:  17 degrees

Maryland Science Center:  21 degrees

Baltimore Sun:  20 degrees

Martin State Airport:  18 degrees

Reagan National:  20 degrees

Dulles International:  15 degrees

Salisbury:  18 degrees

Easton:  19 degrees

Ocean City:  17 degrees

Annapolis:  20 degrees

College Park:  19 degrees

Oakland:  10 degrees

Cumberland:  23 degrees

Gaithersburg:  14 degrees

Posted by Frank Roylance at 11:35 AM | | Comments (6)
Categories: Forecasts
        

January Thaw - fact or myth?

National Severe Storms LaboratoryFROM TODAY'S PRINT EDITIONS:

Rosi McCloskey, in Stewartstown, Pa., asks: “Is the ‘January thaw’ an actual annual occurrence, or just wishful thinking?” 

Maybe both. Stats for the Northeast do show a warm temperature “singularity” around Jan. 20-25. It’s about 6 degrees in Albany, N.Y. But no plausible physical mechanism has been found to explain it.

A Cornell study found the oddity to be “well within the limits of what might be expected to occur by chance alone.” There are other such singularities in the stats, warm and cool. Europeans watch for the “Ice Saints” – a cold spell May 11-14.

(National Severe Storms Laboratory)

Posted by Frank Roylance at 12:01 AM | | Comments (4)
Categories: From the Sun's print edition, Sky Notes
        

January 22, 2011

Forecasters struggle again with Tues/Weds storm

Here we go again. The weather story all winter, it seems, has been one of forecasters and their computer models struggling to get a grip on a repeated pattern of complex storm systems.

AccuWeather.comThis weekend seems to be no exception. Once again, the supercomputers are wrestling with a combination of a clipper-like storm moving out of the Northwest, expected to cross the country's mid-section, converge on a southern low that will cross the South and emerge off the mid-Atlantic coast early next week.

Where will these disturbances go, exactly? When will they get there? Will the systems merge in just the right spot to dump snow? Will one pass to our north or west and bring rain and sleet? Or, will they both veer away and leave us in the bubble again?

AccuWeather.com is already sounding pretty aggressive on this one, although they don't seem to have figured out the storm tracks, either. The NOAA Climate Prediction Center has us in the "Heavy Snow" zone on their forecast map. But the "Heavy Rain" zone is nearby. Foot's Forecast lays out two scenarios. Here's the official forecast from Sterling.

Today's NWS forecast discussion from Sterling contains an unusual admission of the difficulties the folks at Sterling have been having this winter. I present it below, edited only to expand abbreviations:

"MOST OF THE LONG TERM FORECAST WAS SPENT LOOKING AT THE POTENTIAL
COASTAL STORM TUES INTO WED. THIS WINTER HAS FEATURED MANY COMPLEX
STORM SYSTEMS IN THE MEDIUM RANGE THAT HAD A POTENTIAL TO IMPACT
THE AREA. OPERATIONAL MODEL GUIDANCE HAS HANDLED THESE PHASING
SYSTEMS POORLY SO FAR THIS WINTER...RESULTING IN LOWER THAN NORMAL
MODEL SKILL AND FORECAST CONFIDENCE MORE THAN A COUPLE DAYS OUT.

"THE UPCOMING TUE-WED SYSTEM WILL BE NO EXCEPTION. WHILE CONFIDENCE
IS HIGH THAT A COASTAL LOW WILL DEVELOP NEAR THE SOUTHEASTERN
COAST...THE EXACT TRACK OF THE LOW IS HIGHLY UNCERTAIN. THE TRACK
OF THE LOW /WHICH DEPENDS ON THE TIMING AND OCCURRENCE OF PHASING
BETWEEN SOUTHERN AND NORTHERN STREAM DISTURBANCES/ AND THE EASTWARD PROGRESSION OF THE SURFACE HIGH MOVING NORTHEAST OF NEW ENGLAND WILL BE CRITICAL
IN DETERMINING THE PRECIP AMOUNTS AND THE PRECIP TYPE.

"IT IS TOO EARLY AT THE MOMENT TO NAIL DOWN THE SPECIFICS AS THE PRIMARY NORTHERN STREAM ENERGY ASSOCIATED WITH THE UPCOMING STORM IS STILL NEAR THE GULF OF
ALASKA. THE MODELS HOPEFULLY WILL CAPTURE THIS ENERGY BETTER ONCE
IT MOVES INTO WESTERN CANADA TONIGHT INTO SUNDAY.

"AS STATED ABOVE...THE WIDE RANGE OF MODEL SOLUTIONS PROVIDES A WIDE
RANGE OF POSSIBLE IMPACTS FROM THIS SYSTEM. THE WESTERN-TRACK SOLUTIONS
SUCH AS THE 12Z NAM [MODEL] /TOWARD THE END OF ITS RUN/ AND GEM [MODEL] HAVE A
TRACK OF THE LOW CLOSER TO THE APPALACHIAN SPINE THAT WOULD RESULT
IN A MOSTLY RAIN EVENT.

"THE EASTERN-MOST SOLUTION THAT THE 12Z GFS [MODEL RUN] PORTRAYS HAS A TRACK WELL OFF THE COAST...SAVING THE AREA FROM A DIRECT IMPACT. THE MEAN OF THE 12Z GFS ENSEMBLE MEMBERS AND 12Z ECMWF SHOWS A SOLUTION SLIGHTLY WEST OF THE 12Z OPERATIONAL GFS RUN...WHICH WOULD LEAD TO THE BIGGEST IMPACT WITH MORE SNOW THAN
RAIN. COMPARED TO YESTERDAY...

"THERE IS A EASTWARD TREND IN THE TRACK OF THE LOW. GIVEN LATEST TRENDS AND SPREAD IN GUIDANCE...DO NOT FEEL THAT INCREASING [PRECIPITATION PROBABILITIES] IS WARRANTED. HAVE ALSO TRIED TO DETERMINE MOST LIKELY TIME PERIOD FOR PRECIP WITH THIS SYSTEM...WHICH NOW APPEARS TO BE LATE TUES INTO WED.

"WHAT HAPPENS AFTER THIS STORM PULLS AWAY FROM THE AREA WILL DEPEND
ON PRIOR EVENTS WITH THE MIDWEEK SYSTEM. IT DOES APPEAR THAT THE PACIFIC
NORTHWEST JET STREAM REMAINS ACTIVE EVEN INTO THE END OF NEXT WEEK...WITH
RIDGING OVER THE WEST COAST AND TROUGHING OVER THE EASTERN CONTINENTAL US HOLDING
FIRM. THIS PATTERN WILL FAVOR NEAR- TO BELOW-NORMAL TEMPERATURES
CONTINUING INTO THE WEEKEND."

Posted by Frank Roylance at 5:07 PM | | Comments (10)
Categories: Forecasts
        

Mercury reaches 12 degrees at BWI

Pretty cold night. We fell to 9 degrees here on the WeatherDeck in Cockeysville. The low was 12 at BWI, the coldest of the season so far. Here are some readings from around the region at 6 a.m. They are not necessarily to night's lows, but probably pretty close.Icicle

Reagan National: 17 degrees

Dulles International:  14 degrees

College Park:  19 degrees

Gaithersburg:  12 degrees

BWI-Marshall:  14 degrees

Martin State Airport: 16 degrees

Md. Science Center:  17 degrees

Baltimore Sun:  16 degrees

Annapolis:  17 degrees

Ocean City:  19 degrees

Salisbury: 18 degrees

Frederick:  10 degrees

Hagerstown:  11 degrees

Westminster:  10 degrees

Oakland:  0 degrees

Cumberland:  12 degrees

(SUN PHOTO: Frank Roylance, 2010)

Posted by Frank Roylance at 8:20 AM | | Comments (4)
Categories: By the numbers
        

Sunrise, sunset, and the solstices

FROM TODAY'S PRINT EDITIONS:

Last week I told Dennis Ferguson that the sun’s “rise and set points slip south in winter, north in summer, creating our seasons.”  I should have been more precise, and said they move south “with the approach of winter,” and north “as the seasons move toward summer.” Thanks to Dennis Barnes, in Abingdon, for reminding me that after the winter solstice (the traditional start of winter), the sunrise and sunset points begin to return north. And they start south again right after the summer solstice.  

 

 

Posted by Frank Roylance at 12:01 AM | | Comments (0)
Categories: From the Sun's print edition
        

January 21, 2011

Coldest temperatures of the season tonight

If the forecasters out at Sterling have it right, Central Maryland is looking at the coldest temperatures of the season tonight.

NOAA/NWSBWI-Marshall could see an overnight low of just 11 degrees by Saturday morning (map). That would beat the low of 16 degrees reached on Dec. 16. The high for Saturday would struggle for 24 degrees as arctic air continues to rush into the region behind Friday morning's exiting snowstorm.

Marylanders out in the western mountains will see lows near or below zero tonight, with wind chills of minus-5 to minus-15 degrees as winds rise to 20 or 30 mph, gusting to 40, forecasters warned. Wind Chill Advisories are posted for western Allegany County.

In Baltimore, local health officials have declared a Code Blue Health Alert through Sunday, extending hours in the city's shelters and sending outreacher workers to check on vulnerable residents.

The cold will stick around for at least the next week, although temperatures will moderate some along the way. Highs at BWI-Marshall Airport won't reach the freezing mark again until Tuesday, if the forecast holds up. Lows will rise out of the teens by Monday night. This is all far colder than the averages for this time of year. The average high for BWI is now 41 degrees; the low is 23.  

Posted by Frank Roylance at 12:51 PM | | Comments (0)
Categories: Forecasts
        

Maybe next time ...

Puh... Looks like we got just about what forecasters, at the end, said we would. Maybe that's a relief to most. The roads seem to be in fine shape. But it has to be another disappointment for those Marylanders who love to see a good snowstorm now and then.

AccuWeather.comSomehow, school kids (and teachers) in the northern counties will get a more leisurely morning out of it. Two-hour school delays are in place from Carroll across to Cecil.

The reports are still coming in, but at 7 a.m., it looks like Bel Air, with 2.3 inches on the ground at daybreak according to the NWS/ Sterling snow map , gets the brass ring.  CoCoRaHS tallies put Reisterstown in the lead, with 1.9 inches.

So why are we even bothering with this? Perhaps to make the forecast for next Monday night and Tuesday look more interesting. Models are sending another low across the South, and keeping cold air in place just to the north. Sterling is putting the snow chances at 40 percent. But this morning's discussion also has the possibility it will become a drizzle and freezing drizzle event. Nice.

Anyway, AccuWeather.com (map) is watching the models and urging readers to do the same. As our other prognosticators check in with their guesses later today, we'll add them below.

In the meantime, Here's Eric the Red explaining what went wrong with his forecast:

"Well... once again, I've got some explaining to do.  A last-second twist to the forecast left many areas high and dry.  The low nudged just a bit farther north... and with that nudge, 2 things happened: 1) Warmer air on the south side of the storm ended up farther north, causing the precip to the south to fall as rain or rain/snow mix. 2) The southern edge of the precip ended up farther north.

"On a continental scale, we're talking an almost inperceptible blip... but on a local scale, we were right on the line, so the implications were large. In north-central and northeast MD, 2" (locally more) fell.  I noticed at the Halethorpe train station, maybe a half inch, and by the time I got to DC, nothing." 

Here's the overnight storm on radar. And here, on the jump, is Eric the Red's take on next week's storm. In brief: Lots of potential. Lots of uncertainty.

"A major winter storm will likely impact the eastern seaboard early to middle of next week. There are still numerous differences with details, but the overall idea is pretty uniform.  Snow, ice, and rain will spread up the East Coast early next week, and the precip could become quite heavy.  This whole mess will start late Monday or early Tuesday... and last into Wednesday.

"Details:  An upper-air low will drop from the Dakotas into the Ohio and Tennessee Valleys over the weekend, while a surface low develops in the Gulf and moves northeast along the coast.  Energy from the western low will begin to transfer to the coastal low and cause the coastal low to rapdily intensify. 

"This process is where some of the uncertainty lies; if it happens too late, then New England gets whallopped... and we're left once again to ponder what could've been.  If it happens too soon, we could end up with ice or rain as a wound-up coastal low throws warm air into the equation

"Or, it could be - like the third bowl of porridge - juuuust right.  The other issue will be the exact storm track... Obviously, if it tracks too far offshore, that as they say is that.

"I'll say this:  The set up is favorable for a big-time winter storm.  Arctic air is blasting into the region now, we'll have a high to our north, lots of energy feeding into the system aloft, plenty of time to tap into Gulf and Atlantic moisture, and a sfc low along the coast. 

"If there's something I'm a bit worried about that could hose us... it would be if the coastal low tracks too far inland, which would give us snow to sleet to freezing rain to rain.  It's way too early to say if this will indeed be the case.  In simple terms, it will boil down to the track of the coastal low and how quickly it intensifies.... impossible to predict at this point."

And, here's how Foot's Forecast analyzed the outcome of their 2-4-inch forecast for last night's storm. Nothing from the students yet on next week's threat:

"We originally projected a general 2-4” and we believe that busted in most areas. Among the factors which affected the outcome:

"1.) There was a lot of dry air ...in place when the snow arrived, so that kept the snow from falling immediately, and that prevented a lot of snow from reaching the ground (we call it "wasted snow.");

"2.) The low pressure was projected to track just south of Central MD and through northern VA. Instead it tracked directly over Central MD. This was not the ideal track for us to get higher amounts, as it shifted the heaviest snow amounts just a mere 100 miles north."

Posted by Frank Roylance at 7:01 AM | | Comments (15)
Categories: Winter weather
        

CoCoRaHS Network needs volunteers

FROM TODAY'S PRINT EDITIONS:

Measuring snowEverybody complains about the weather, but too few of us do anything about it. Now you can.

Volunteers with CoCoRaHS, the Community Collaborative Rain, Hail and Snow Network, measure and report daily precipitation. CoCoRaHS then generates online rain, snow and hail maps used by the NWS, emergency managers, the media and others.

More volunteers are needed, especially in and around Baltimore. For more info, or to sign up, visit  www.cocorahs.org

(SUN PHOTO: Amy Davis, 2003)

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: From the Sun's print edition, Sky Notes
        

January 20, 2011

Forecast scaled back to 1-3 inches

Looks like this will be yet another annoying little snowstorm of just 1 to 3 inches. The storm approaching from the west just doesn't carry very much moisture, forecasters say. And the southern storm is expected to move out to sea without providing much energy or moisture to the game.

NWS/NOAAThe National Weather Service in Sterling, Va. has posted a Winter Weather Advisory , covering the northern tier of counties from Frederick to Carroll, Howard, Baltimore and Harford counties, including the City of Baltimore, and the northern counties of the Eastern Shore.

South of there, the forecast accumulations diminish and the potential impacts on travelers does the same. Little or no accumulation is expected in Southern Maryland or the Lower Eastern Shore. Here's how this morning's forecast discussion from Sterling put it:

"Northern Maryland, Potomac Highlands stand best chance at receiving a couple inches of snow accumulation. Could see southern counties struggling to get an inch out of this. And that's still subject to change. DC right now on the edge..." 

The snow is expected to reach the Baltimore area between 10 p.m. and midnight, tapering off around daybreak Friday, with the highest accumulations closer to the Mason-Dixon Line. Could this be another Hereford Zone storm?

As minor as it seems, the snow could still produce slippery walking and driving conditions. Temperatures overnight will be in the upper 20s, and will stay fairly cold on Friday. The forecast high for BWI-Marshall is only 31 degrees. Watch for re-freezing of earlier snow melt. I nearly took a header on some black ice this morning.

Friday night and Saturday will see some of the coldest temperatures so far this winter, with an overnight low near 14 degrees at BWI, and a Saturday high of just 25 degrees - 10 to 15 degrees below the averages for this time of year.

The weekend will remain unusually cold, with highs in the 20s and lows in the teens.

Then, there may be m ore disappointment ahead for snow lovers hoping that next week's storm will redeem all that have come before it this winter. Here, on the jump, is Eric the Red's dispiriting assessment of the various model solutions:

"The ECMWF and NOGAPS remain ominous, with a dual-part system impacting the region on Tuesday (a coastal low and a western upper-air low)... with heavy snow, sleet, and or freezing rain.

"On the other hand, the GFS has really backed off, and has a weak coastal low and not much else... with light snow on Tues. 

"The Canadian, which was all down and jiggy with a big storm in yesterday's runs, has totally backed off too... with light snow Monday night into Tuesday. 

"From this mess I can't really extract anything terribly confident... just that we'll keep an eye on early to middle of next week for a potential winter storm.  Persistence would dictate a miss, but we're due, right?! "

Posted by Frank Roylance at 9:59 AM | | Comments (11)
Categories: Forecasts, Sky Notes
        

Perigee makes the Old Moon look bigger

FROM TODAY'S PRINT EDITIONS:

Full Moon over BaltimoreYes, that was a full moon last night. It was the first since the winter solstice, so that makes it the Moon After Yule, or the Old Moon.

It would be nearly as full tonight, if you could see it. Skies should clear by Friday night.

And if the moon looks unusually big to you then, that’s because it will be at perigee – its closest approach to Earth this month.

On Mar. 19, the closest lunar perigee of the year will occur simultaneously with the full moon. Watch for unusually high tides. 

(SUN PHOTO: Karl Merton Ferron, 2004)

Posted by Frank Roylance at 12:01 AM | | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

January 19, 2011

NWS now predicting 2-4 inches for Baltimore

The afternoon update to the NWS forecast for the storm approaching late Thursday calls for 2 to 4 inches of snow in the city, as well as its northern and western suburbs. A 1-to-3-inch snowfall is AccuWeather.comexpected at BWI and points south and east, with little or none on the Lower Shore.

The predictions come with the usual caveat: the storm's final track could change things. But it would seem that a shift in the predicted path of this event would likely bring more warm air into the region and decrease accumulations, rather than increase them. That's been the pattern this winter; our surprises have generally meant less snow, not more (the reverse of last winter's pattern).

The official forecast for BWI-Marshall Airport calls for rain or snow beginning before 9 p.m., changing to all-snow overnight, with 1 to 3 inches on the ground by daybreak.

In the city, in Towson, Bel Air, Westminster and Columbia, the predicted accumulations look more like 2 to 4 inches, forecasters said. Pajamas ..... inside out, kids.

By afternoon Friday, the sun should reappear, leading into a cold but sunny weekend. The next storm is expected Tuesday or Wednesday of next week.

Posted by Frank Roylance at 5:21 PM | | Comments (1)
Categories: Forecasts
        

Next storm may be sloppy repeat

You can say one thing for this winter's weather. It's consistent. Complex storm systems bring southern lows up, or off, the coast, while another low moves out of the west or the Great Lakes. The two fail to merge or "phase," and we get a few inches of snow or a sloppy/icy mess.

And that seems to be what's shaping up again for Thursday night into Friday. Forecasters at the National Weather Service forecast office in Sterling, Va. are tracking a weak southern low that they NWS/NOAAexpect will emerge somewhere off the mid-Atlantic coast by Thursday night. Another storm system sliding in from the west is not expected to hook up with the coastal low in time.

Depending on storm tracks, that could mean one of several outcomes, forecasters say. One computer model sets up the coastal low off Delmarva with rapid intensification Thursday evening. That would mean snow for the entire forecast area until daybreak Friday.

Another model slows the storm down and takes it across Delaware Bay. That would allow more warm air into our region, mixing up the precipitation and limiting accumulations, if any.

While the other models seem to be favoring the latter scenario, forecasters at Sterling, being extra cautious, are siding with the former. AccuWeather.com is expected 1 to 3 inches in Central Maryland, with 3 to 6 to our north and west. NWS/NOAA

The official forecast at this point (late morning Wednesday) calls for a 90 percent chance of snow at BWI-Marshall, beginning after 9 p.m. Thursday night, with an overnight low of 28 degrees.

The snow chances slip to 40 percent Friday morning, ending before noon. Skies would then clear off quickly, leading to a sunny but colder, gusty day, with a high back down in the mid-30s. Friday night lows would drop back into the teens. And while the weekend would be sunny, temperatures would struggle to reach the freezing mark Saturday.

The NWS snow map (right), at least through 1 a.m., shows less than an inch in Central Maryland. But that series of forecast maps does not yet get us to daybreak Friday. Watch this space.

Eric the Red, a professional forecaster from Baltimore, is siding with a reprise of recent storms, with little accumulation, again:

"If you take the just-in guidance at face value... it would be 1-2" of snow in the DC area, 1-3" in central MD, and 2-4" across northern MD.  As I mentioned yesterday, if I had to pick which way this would go... it would be lighter, in line with persistence." 

Our next shot at some accumulating snow may come early next week. And AccuWeather.com forecasters see the pattern continuing: "There are more storms on deck for the following couple of weeks. At least one of these has the potential to be another blockbuster for some areas."

Stupendous snow total for the season so far at BWI-Marshall Airport?  4.7 inches. We haven't even reached the low-bidder (7 inches) in our "Guess the Season's Snow Total Contest."

Pitiful, don't you think? Seems to me we passed 4.7 inches in the first few hours of the Dec. 18-19 storm last winter.

UPDATE, 2 p.m.: Eric the Red has updated his outlook for the Thursday-Friday snow, and added his speculation about next week. And next month. Read on below.  

"Next week... Jiggyness.  Models are all over the place... but on this they agree:  Something will spin up over the southern US and move northeast. 

"The NOGAPS has a snowstorm Monday night, but it's outta here by Tues.  The GFS has what looks like freezing drizzle or light snow Monday night, and then an extended period of light to moderate snow Tues into Weds morning as a low crawls up the coast (yeah, right).  The Canadian [model] takes forever to get the storm out of the south... and it brings it right up I-95... with rain or ice Weds night and Thrs.  Ugggghhhh.  

"The ECMWF has a very ominous-looking low in the northeastern Gulf on Tuesday... and based on the current fcst track, would bring a world of hurt to the eastern U.S. Tuesday into Weds... like heavy snow, sleet, freezing rain, and rain as the low tracks right up the I-95 corridor. 

"So, next week could very well be the make-or-break storm of our winter.  Why?  well I'm flattered you want to know.  Read on.

"Last week of January looks like it may very well spell the end of an era.  After 18 months of north Atlantic blocking highs... the last couple of long-term model runs finally have a wholesale pattern change, as the peristsent blocking high over the northern Atlantic breaks down and is replaced by fast, west-east flow at the jet stream level over eastern Canada and the north Atlantic.  This in turn would ultimately put an end to the never-ending assault of cold air in the eastern U.S. 

"The northern Atlantic pattern is expected to do a full reset on or about Feb 1, so we may very well be dealing with the last 2 weeks of wintry weather, barring a quick return of the blocking high (which based on the latest fcst charts does not look likely).  Basically, once the block breaks down, we'll start to see an onslaught of much milder, Pacific air masses.  Again, the target date is ~ Feb 1.  That leaves us 2 weeks to get some snow."

Posted by Frank Roylance at 10:45 AM | | Comments (9)
Categories: Forecasts
        

January 18, 2011

Several inches of snow possible Thurs. night

Forecasters are weighing the chances we'll see some more snow showers tonight, along with what should be mostly rain showers. But there's a more significant chance that the next few inches of snow we see will arrive late Thursday into Friday.

AccuWeather.com sees a pattern here, and predicts more storms like these - and maybe a bigger one - right into February. 

Tonight's disturbance in The Force will come with a little system due to swing throught the region early Wednesday morning. Forecasters and their computer models aren't sure whether much or ice stormany of it will fall as snow. Temperatures will hang right near the freezing mark. But the snow and ice cover could drop temperatures in some locations low enough to allow some flakes to form.

In any event, there's not much moisture with the system, NWS forecasters say. So they're not terribly concerned about accumulations. "If there were to be any snow accumulation, it would be spotty along the Pa. border," the discussion from Sterling advises.

Eric the Red urges caution when you step out Wednesday morning: "Be alert ... for pockets of freezing rain ... Most urban areas will be rain, but outside the beltways could be dicey."

More intertesting is the next system, which arrives late Thursday after a sunny break Wednesday afternoon and Thursday daytime. The NWS is giving it a 50 percent chance of snow showers AccuWeather.comThursday night, slipping to 40 percent Friday morning.

The weather service describes the storm as carrying more moisture than tonight's, but dropping down from the Great Lakes and intensifying off the coast to our east Friday.

"Low-level thickness [of cold air] supports wintry precipitation further south than the mid-week upper wave," Sterling says. "Chances for snow a bit better across the area, but again only light [precipitation] expected, and of a scattered and intermittent nature."

Eric the Red sees it this way: "...[A] swath of snow north of the storm center and a mixed mess along and south of the storm track. This would put much of northern VA and central/northern MD in line for several inches of snow. The [model] consensus is 2-4"... with some heavier (the WRF/NAM looks more like 4-8", and the Canadian is heavier too), while the GFS is a bit lighter (1-3").

"I kinda like the 2-4" forecast meself ... Friday morning rush hour looks like fun."

Much depends on the storm tracks. Eric lays down three scenarios: "1) Storm is faster and weaker, and produces a quick-hitting trace to an inch... if that. 2) The storm tracks farther north, and gives us sleet and freezing rain instead of snow. 3) The storm deepens more rapidly than expected, which would push totals up."

Foot's Forecast advises: "This potential second round of winter weather would understandably wreak havoc with school schedules in areas just affected by today's event. School administrators faced with the task of rescheduling mid-terms are advised to continue monitoring statements by their local NWS forecast office as well as our regional facebook forecast centers for the latest developments on this possible "round two."

(SUN PHOTO: Jeffrey Bill)

Posted by Frank Roylance at 1:53 PM | | Comments (2)
Categories: Forecasts
        

Icy rain ending between 9 and noon

The snow, sleet and freezing rain that have put a glaze on Central Maryland were forecast to end as early as 9 a.m. But the mess they have left behind will not go away quite that quickly.

The National Weather Service has posted a Winter Storm Warning until noon for Central Maryland, including Baltimore city and county, Frederick, Carroll, Howard, Montgomery and Harford counties. In this case the warning means we can expect up to a quarter-inch of iceNWS/NOAA accumulations before it ends between 9 and noon. Radar shows the precipitation already mostly clear of the region.

UPDATE, 10 a.m.: The Warning has been replaced by a Winter Weather Advisory for Carroll, Baltimore and Harford counties:

"BUT FREEZING DRIZZLE WILL LINGER ACROSS THE BALTIMORE AREA.
THIS WILL GO UNTIL NOON.

"EXISTING ADVISORY FOR THE NORTHWEST DC SUBURBS AND EXTREME EASTERN WV PANHANDLE WILL ALSO CONTINUE TIL
NOON FOR FREEZING DRIZZLE."

UPDATE: 11 a.m.: The NWS has canceled the Winter Weather Advisory. The northwest suburbs will remain near freezing into the early afternoon. Untreated roads and sidewalks will remain slippery.

.Taneytown has reported 3 inches of snow and sleet accumulation. Frostburg has 2 inches. But the real story today is ice. Here's the NWS snow and ice map.

The storm does not seem to have caused very many power outages. BGE's website is reporting only a few hundred customers still out this morning, and another 1,600 or so already restored.

Farther south, in PG and Arundel and points south, the precipitation will end between 7 and 9 a.m. after depositing only a few hundredths of and inch of ice.

The glaze has closed or delayed classes throughout the area, with some serious accidents across the region. The main routes, however seemed well treated in advance of the storm.

Baltmore Sun Weather StationThe good news is that temperatures have been rising all night, and hovered near the freezing mark at daybreak. That trend should continue, with highs later today (Tuesday) in the upper 30s.

But don't expect the sun to come bursting through anytime today. The forecast calls for rain chances to continue through Wednesday morning, with clouds finally breaking up in the afternoon. Colder weather returns Wednesday night, with highs only in the 30s, and a chance for snow showers Thursday night into Friday.

So how are you coping with the ice? How are the roads and sidewalks in your location? Will you be telecommuting this morning? Any tree damage? Power out?  Or is this a non-event for you?

 

Posted by Frank Roylance at 6:47 AM | | Comments (7)
Categories: Winter weather
        

January 17, 2011

A wintry mess on tap

It's hard to find anything good to say about the forecast for Monday night and Tuesday morning, except that we're not likely to be buried in snow by the coastal low that's headed this way, or the western low that is headed for the Ohio Valley.

What is due to fall, looks like a slippery mess. And then there's the storm at the end of the week AccuWeather.comwe've got to look forward to. More on that shortly.

The National Weather Service has placed the entire state - except for the Lower Eastern Shore - under a Winter Weather Advisory. That's going to mean very different things depending on where you are.

For those close to BWI-Marshall, it means the night will begin with snow and sleet before 9 p.m., changing to sleet and freezing rain for a few hours, and then just freezing rain into Tuesday morning.

Freezing rain, of course, means rain falling out of relatively warm air aloft, landing on still-very-cold surfaces and creating a coating of ice there. That coating could accumulate to froma tenth to a third of an inch. The snow and sleet should amount to very little - less than half an inch.

Clearly it will be a very slippery morning for some. I suspect the main roads will be okay. I saw trucks out today spraying brine on the interstates to get them ready for the frozen stuff. But your front steps, sidewalks, your cars and your local streets may well be ice-covered and treacherous. So please keep that in mind as you head out tomorrow morning.NOAA photo

The freezing rain will eventually change to all rain, with a daytime high Tuesday forecast at 38 degrees.

Here's AccuWeather's story.

Elsewhere, what you encounter out there will vary widely with location. Here's Eric the Red's take on that:

"Along and east of I-95, there will be enough warm air to push temps above freezing by sunrise.  But west of I-95 in the Piedmont... and out in the mountains, the cold air will be slower to erode, and a prolonged period of freezing rain is likely into the morning hours. 

"It will all boil down to exactly where the surface low tracks; if it's too close to the coast, the warm air from the ocean will get thrown pretty far west... while if the low is just a hair farther east, it would keep winds out of the northeast and maintain cold air near the surface. 

"I think it's prudent to go with climatology... and bet on widespread freezing rain in the morning west of I-95, and many areas out toward the mountains may never get above freezing."

And here's Eric on the Friday storm:

"We will be keeping an eye on a storm for Friday as well.  The Canadian has quite a snowstorm, while the GFS is much lighter (a couple inches).  So the end of the week could get dicey too."

More later in the week.

(NOAA PHOTO)

Posted by Frank Roylance at 5:54 PM | | Comments (0)
Categories: Forecasts
        

January 16, 2011

Where does the day begin?

FROM TODAY'S PRINT EDITIONS:

TuvaluIke, from Jarrettsville, asks via snail mail: “In what part of the world does the day begin? If it’s 5 a.m. in Rome, then five hours east would put the beginning somewhere in Asia. I’m guessing China.” Nope. The calendar date begins wherever it’s midnight, and midnight circles the globe daily, east to west. A Sunday becomes a Monday in the mid-Pacific if you cross the International Date Line, east to west. That happens at whatever hour you cross. 

(AP PHOTO: Richard Vogel, Tuvalu Island, near the International Date Line)

Posted by Frank Roylance at 12:01 AM | | Comments (5)
Categories: From the Sun's print edition
        

January 15, 2011

Rain, snow today no worry; Monday night nastier

Forecasters don't expect this evening's rain and snow showers to amount to anything. And Sunday looks sunny. But the forecast for the holiday on Monday looks much nastier, with a "wintry mix" promising to mess things up north and west of the urban centers.Wintry mix

"If this were to verify," said Eric the Red, "we'd be looking at a pretty significant winter storm for Monday night into Tues. ... with snow changing to sleet and likely followed by a prolonged period of freezing rain."

NWSThe National Weather Service says surface temperatures here on Monday will remain pretty cold as low pressure now organizing over Texas, approaches from the south. That will send warm air from the south rising up and over the colder, denser surface air. That surface layer will be cold enough and deep enough to produce snow at the beginning of the event.

But with time, the cold air will erode, and the snow will start changing to sleet, then freezing rain, especially west of the Blue Ridge and across Northern Maryland. The freezing rain could persist long enough to put a glaze of ice on everything. Please watch your step and be careful on the roads Monday night.

Finally, as the surface air warms, and the southern low moves up the coast, it will become all rain. Tuesday will be rainy, but as the low moves off, the wind will shift to the northwest, colder air will move in and whatever precipitation remains may change to snow before ending.

And then things will shift back to the below-average cold conditions that have prevailed for most of the time since early December, with highs - which average in the low 40s at this time of year in Baltimore - only in the low- to mid-30s.

Posted by Frank Roylance at 12:17 PM | | Comments (1)
Categories: Forecasts
        

The sun also rises, but not always due east

FROM TODAY'S PRINT EDITIONS:

Sunrise AssateagueDennis Ferguson, writes from Easton: In childhood, we learned that the sun rises in the east and sets in the west. Over the years, I’ve noticed that that sun doesn’t always rise (or set) in the same place … What would account for this?”  It’s the 23.4-degree tilt in Earth’s axis. For thousands of years, humans have noted that the sun only rises due east at the spring and autumn equinoxes. Rise and set points slip south in winter, north in summer, creating our seasons.

(SUN PHOTO: Andre Chung, 2005) 

Posted by Frank Roylance at 12:01 AM | | Comments (0)
Categories: From the Sun's print edition
        

January 14, 2011

Wintry Game Day forecast for Pittsburgh

Pittsburgh in WinterAre you headed for Pittsburgh for Saturday's bout between the Ravens and the Steelers? If so, you're probably already planning to dress for winter in Western Pennsylvania.

The National Weather Service forecast for the city at the confluence of the Allegheny and Monongahela rivers looks about like it almost always does at this time of year: cold and gray and snowy.

Meteorologists expect cloudy skies Saturday, and a high near 35 degrees, falling toward an overnight low of 19 degrees.

Also, they say: "Snow showers likely, mainly after 9am. Southwest wind between 9 and 14 mph. Chance of precipitation is 60%. New snow accumulation of 1 to 2 inches possible."

(AP Photo:  Keith Srakocic, Pittsburgh, Jan. 12, 2011)

 

Posted by Frank Roylance at 3:30 PM | | Comments (0)
Categories: Forecasts
        

Cold? This isn't cold. Forty-below is cold

The mercury here at The Sun is struggling to top the freezing mark today. Ten of the last 11 days have been below the seasonal norms at BWI-Marshall Airport. And 23 days in December were below the long-term averages, too. The average high for this date in Baltimore is 41. Our persistent cold weather comes to us courtesy of something called the Arctic Oscillation. You can read more on that, and La Nina, here. 

Sun thermometer

But we're a long way from the record-cold days our parents and grandparents experienced. Thursday was the 99th anniversary of the day in 1912 when thermometers in Oakland, out in Garrett County, registered 40 degrees below zero. That was, and still is, the record-cold reading for the state.

The high reading in Baltimore that day (Jan. 13, 1912) was 11 degrees, still a record low maximum for the date. The next morning, the low in Baltimore was minus-2 degrees, also still a record for a Jan. 14.

Cold in 1955Thirteen years later, on Jan. 28, 1925, the low reading in Oakland was minus-31 degrees. Twice in the following 30 years the temperatures in that far Western Maryland burgh reached a negative 25 degrees. And on Jan. 28, 1955 they reached minus-26 degrees, according to our clips from the time.

Trust me, that's cold. Not long after we were married, my wife and I were living in Hanover, N.H. During our first or second winter there, the overnight temperatures fell to minus-27 degrees three days in a row. We quickly learned to bring our car battery indoors for the night, or face the certainty that the old crate would not turn over in the morning.

We later purchased a crankcase heater, and used that to keep the engine warm overnight. It consisted of little more than a heated dipstick with an electrical cord.

But with no place to plug it in at work, I was reduced to visiting the parking lot every two hours, during coffee breaks and lunch, to start and run the engine for 15 minutes. If I hadn't, by quitting time it would have been as inert as New Hampshire granite. The highs on those days failed to reach zero.

But I digress. On Jan. 28, 1955, The Sun reported that the low in Baltimore was 14 degrees above zero at daybreak. Cumberland reported a reading of zero. The Sun observed:

"The air, particularly cold because it had moved here rapidly from the Arctic, put heavy coatings of ice on lakes and ponds and gave skating enthusiasts continued sport.

"In the harbor, plumes of thick frost decorated masts and rigging and ships and coated piers. Service stations did a land-office business throught the night..."

(Thanks to Sun Librarian Paul McCardell)

Posted by Frank Roylance at 1:29 PM | | Comments (0)
Categories: By the numbers
        

No, your astrological sign hasn't changed

When I saw Thursday evening that this goofy story on the "changes" in the dates and names of our astrological signs was the most popular item on our Web site, I told our editors that it was badly garbled, and mostly wrong.

There was nothing they could do. It was inserted by editors in Chicago, and Baltimore had no Ophiuchuscontrol over it.

It apparently began with a legitimate astronomer, interviewed on a TV station, who noted that the sun is not really passing through the constellation, or astrological "sign" that one would think, based on the dates published in the newspaper every day for as long as anyone can remember.

That means many of us were not really born under the signs we thought we were (if we thought about it at all). And some of us (myself among them) were born under a sign we'd never heard of -Ophiuchus (left). 

That much is astronomical fact. But the story on the TV station's website was pretty confused, and once everyone else began picking it up, it became hopelessly garbled. 

The bottom line is this: This "drift" in the sun's apparent position relative to the background stars and constellations has been known and understood by ASTRONOMERS and ASTROLOGERS since the Greek astronomer Hipparchus figured it out in 134 BC. 

It's called the "precession of the equinoxes." And since 600 BC, it has moved the actual position of the sun against the background constellations about a month out of synch with the astrologers' traditional frame of reference. 

Astrologers who use the dates and positions dictated by Near Eastern astronomers hundreds of years before the Christian Era are well aware of it, and they don't care. They're not going to change the dates they use, and they're not going to add a "13th sign" - Ophiuchus - to the Zodiac.

I first became aware of this particular disconnect between astronomy and astrology in 2004, and I wrote a story about it for The Sun. I've pasted it in below. Read and learn, as I did.

By Frank D. Roylance, Baltimore Sun, First published Dec. 31, 2004

    Let's get one thing straight. I don't believe in astrology. But the daily horoscopes seem harmless enough back there with the funny pages, offering sensible, all-purpose advice.

    For example, The Sun's syndicated astrologer recently urged those born under Pisces to "back up computer files, and make sure your cell phone battery is charged." No argument there.That said, I confess that I can't wait until the next time somebody asks my astrological "sign." That's because I've been spending a lot of time with a computer program for backyard stargazers called Starry Night, published by Imaginova. It's a powerful tool for anyone curious about the night sky - like having Carl Sagan's ghost beside you on a magic-carpet tour of the night sky, and of all time and space. 

    I've discovered something deep inside this fascinating software that should kick the astrological legs out from under millions of believers. Although it probably won't.

    First, those dates you see in the newspaper, bracketing each of the 12 astrological signs? They're all wrong. And, because of something called the "precession of the equinoxes," they've been getting more and more out-of-whack since about 600 BC, when the astrological system was concocted.

    Second, because the dates are all wrong, almost nobody living today was actually born under the sign they think they were. Which means they've been reading - and taking - the wrong advice all their lives. No wonder the world is a mess!

    Third, and this is the most delicious part, those of us born between Nov. 30 and Dec. 17 aren't Sagittarians, as we have always believed. We were born with the sun in the constellation - get this - Ophiuchus.

    That's right: Ophiuchus, the serpent-bearer. It's pronounced Offy-YUK-us, and I had never heard of him either. No syndicated astrologer has ever offered a lick of advice to any of us Ophiuchans. But Starry Night displays his constellation big and bold, with his foot stuck right there between Scorpio and Sagittarius.

    What does it mean to say the sun is "in" a constellation? Well, remember that the sun is always perched in the sky against a backdrop of stars and constellations. We can't see the stars in the daytime (except briefly during a solar eclipse) because the sun's too bright.

    But we know the constellations are there. We can even see them in our night sky six months later, when the Earth has moved to the opposite side of the solar system.

    Think of the setup as a circular room with 12 portraits hanging on the wall. Each painting represents a constellation of stars. The sun is at the center of the room. As we (Earth) orbit around it, the sun appears to move in the opposite direction relative to the portraits in the background. Over one year, the sun seems to move through the full circle of paintings - all 12 constellations of the zodiac.

    Now I always believed I was born with the sun in Sagittarius (the guy with the bow and arrow). But it turns out, according to Starry Night, that nobody born on Dec. 10 has been a Sagittarian since 1582.

    HoroscopeWhen I set Starry Night's controls for my birth date, Dec. 10, and run the years backward, the computer puts all the heavens in motion. I can watch the sun move slowly eastward each Dec. 10 until 1582, when it finally pops back into Sagittarius - where it had been since at least 600 BC.

    Likewise, when I run the years forward from Dec. 10, 2004, the sun "precesses" - creeps slowly westward on the screen each Dec. 10 until the year 2770 or so, when it finally crosses from Ophiuchus into Scorpio (the scorpion).

    Who knew? Have astrologers been keeping this secret for 2,000 years?

    Not exactly. They're well aware of precession. And they're rolling with it.

    "When empirical data begins to disagree with a belief system, we reach a moment ... where you're either going to go with the data or with what you believe," said Holiday Mathis, who writes The Sun's astrology feature.

    Whether the western astrological zodiac matches up with the stars or not "is a moot point," she said. "The archetypes are only as meaningful as we attribute meaning to them. If they do not resonate inside of a person, then astrology is not for that person."

    The western astrologers' zodiac starts in whatever constellation the sun happens to be in on the vernal equinox - the first day of spring. They simply call it Aries (the ram), and apply all of Aries' relevant influences to their recommendations - regardless of what constellation the sun is really in. But more on that in a minute.

    According to Starry Night's "SkyGuide," the eminently readable text that serves as the user's guide and companion, the ancient astronomers who first formalized western astrology hadn't yet discovered "precession."

    They only saw that as a year went by, the sun moved along a celestial trail called the "ecliptic," slipping through a series of 12 constellations. Back then, the sun began its year at the vernal equinox when the sun really was in the constellation Aries. It spent about a month in each subsequent "house" before returning to Aries the following spring.

    Starry Night puts the sun in motion for you, and you can watch it glide through the year, from Sagittarius to Capricorn to Aquarius and so on, all the way around the sky. The ancients believed that our lives are influenced by whichever constellation the sun was traversing at the time we were born.

    Which scientists dismiss as poppycock, of course.

    "It's disturbing that people may be basing life decisions on something that ridiculous," said Dan Caton, a professor of astronomy at Appalachian State University in Boone, N.C., who has written columns in the Charlotte Observer debunking newspaper astrologists.

    There's no basis in science for a connection between the position of the stars and planets and the course of human lives, he said. And repeated statistical studies have found no evidence for such a connection.

    If the stars did influence our lives, he agreed, precession should become a concern - yet astrologers ignore it. But he insisted that "precession doesn't even matter. It's a third-order effect on a mechanism that's not there."

    It was the Greek astronomer Hipparchus who figured out in 134 BC that the astrologers' celestial frame of reference was moving. The spinning Earth wobbles slowly around its axis, like a slowing toy top, because of the gravitational tug of the moon. That wobble rotates in a 25,800-year cycle that gradually pushes the vernal equinox westward around the sky, throwing off all the zodiac's original dates.

    Since 600 BC, it has moved about 36 degrees, or one-tenth of the way around the zodiac. That's almost a whole month. It's like taking all the Beltway exit signs and moving each one to the next ramp.

    So, while newspaper astrologers still insist that anyone born on June 30 is a Cancer (the crab), those people were actually born with the sun in the constellation Gemini (the twins). The "real" Gemini now goes from June 20 to July 20. Then the real Cancer starts and lasts until Aug. 9.

    Precession also allowed the late-autumn sun to slip into all-new constellation territory, which is how Ophiuchus barged into the lineup between Scorpio and Sagittarius.

    It gets even squirrelier. The astrologers divided the sun's path along the ecliptic into 12 even segments - one per constellation. But constellations aren't all the same size, and it takes the sun longer to cross some than others.

    For example, it takes the sun from Sept. 16 until Oct. 30 to make its way across Virgo - that's 45 days. But it dashes through Scorpio in just a week, from Nov. 23 until Nov. 29.

    Now, if you believe that the positions of stars and planets influence your life, wouldn't it be important to know which constellation the sun was really in on your birthday, or any other day?

    Turns out it's not.

    Astrologers such as Mathis say they use the "tropical zodiac," which means they start their celestial year from the vernal equinox and call it Aries, no matter where the sun really is among the constellations.

    From there, they simply measure out each subsequent "sign" in 12 segments of 30 degrees each. The actual positions of the stars and constellations don't matter anymore. Their names are used as a matter of convenience and, as Mathis says, "mythology and storytelling."

    If nothing else, this little lesson demonstrates that there's a vast universe of both stars and ideas out there, with all kinds of surprises.

    For information on Starry Night, visit www.starrynight.com.

Posted by Frank Roylance at 10:37 AM | | Comments (19)
Categories: Notes to readers
        

Friends, Romans ... Happy New Year!

FROM TODAY'S PRINT EDITIONS:

Roman ruinHappy New Year to all of Rome. This is the first day of the year 2764 under the old Julian Calendar instituted in 45 B.C. by the Roman dictator Julius Caesar. He dated it from the supposed time of the city’s founding 709 years earlier.

Pope Gregory XIII replaced it in 1584 with the modern Gregorian Calendar because it had fallen 10 days behind the seasons.

The Julian reckoning is now 13 days behind. It will lose another day by January 2101.

(PHOTO: Allison Long, Kansas City Star)

Posted by Frank Roylance at 12:01 AM | | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

January 13, 2011

"Star of David" snowflakes in Baltimore

Moshe Miller has sent us a fun video this afternoon. Snowflakes in the shape of the Star of David, shot in Baltimore in Tuesday. Here's his note:

"The right atmospheric conditions and temperature over NW Baltimore, MD this past Tuesday, allowed this light dusting of solid snowflakes.  Many of these hard crystals were shaped perfectly as Stars of David. Amazing!  It really makes me give praise to the Creator of the Universe for sharing this laser-precision natural gem with us."

"If you're looking for a deeper meaning, I had this thought.  In the Biblical description of the first Six Days of Creation, the third day (Tuesday) was the only day the words "and it was good" was written twice (a positive sign).

"Also, it dawned on me that the one and only Creator chose the Gregorian/Christian calendar date of 1/11/11 to share this with us . . . As the Baltimore motto goes, "Believe . . . Behave".  Y’know, could that be “Believe in One Creator? Behave to all people?”  Maybe Baltimore is on to something . . . Ma Rabu Ma'asecha Hashem!"

Posted by Frank Roylance at 4:19 PM | | Comments (2)
Categories: Cool pictures
        

Need more snow? Go west

By this date last year, BWI-Marshall Airport had already recorded 21.9 inches of snow, beating the annual average for Baltimore. This year we've seen just 3.5 inches. What a difference a year, and maybe a La Nina can make.

If that's a disappointment to you, you can fix things simply by hopping in your car and driving outNWS to Garrett County. After 10 or 12 feet of snow last winter, those hardy folks are looking at an unbroken line of snowflake icons on their 7-day forecast. Moisture off Lakes Michigan and Erie, coupled with persistent winds from the northwest, are producing a more or less steady fall of snow this week.

WISP web camThe WISP Resort in McHenry has measured 102 inches of snow so far this season, including the 30 inches they've received this week. All the trails are open and there's plenty of winter to go around out there. Garrett County was under a Winter Storm Warning until 11 a.m. today, with another 1 to 3 inches of snow due, and sub-zero wind chills. Snow showers and flurries are likely to continue.

Pretty much the same forecast - snow chances and sub-freezing cold - will hold for Pittsburgh, too, as the Ravens head out there Saturday for the divisional playoff game.

If you're happy we haven't seen a big snowfall yet in Baltimore, and no desire to seek more, you'll be okay with the forecast for Central Maryland.

Aside from a chance for flurries Friday morning as a small disturbance rolls off the Great Lakes and across the area, the trends point to some warming - into the low 40s by Tuesday - and maybe some rain by early next week.

For now, it will remain about 10 degrees below the seasonal norms, with overnight lows in the teens. Baltimore City Public Works officials say it's a good time to think about protecting your pipes from freezing damage, and your home from a wet mess. Here are some tipes from the DPW. 

Meanwhile, residents of the Southland and New England continue to dig out. Here's a pretty cool satellite shot of the snow in the Deep South.

Posted by Frank Roylance at 10:34 AM | | Comments (1)
Categories: Forecasts
        

Int'l Space Station over Baltimore this evening

FROM TODAY'S PRINT EDITIONS:

ISS/NASASpace Cadets! Step out tonight as the International Space Station makes a pass almost directly over Baltimore. Watch as it soars from high over Lake Michigan, to Ocean City and out to sea. If skies are dark enough and clear, the ISS will rise above the northwest horizon at 5:17 p.m. and be 218 miles over your head by 5:20 p.m. The station, with its crew of six, will seem to skim past the moon before fading out in the southeast at 5:23.  

(NASA PHOTO)

Posted by Frank Roylance at 12:01 AM | | Comments (4)
Categories: Sky Notes, Sky Watching
        

January 12, 2011

NOAA: 2010 was wettest globally, tied for warmest

The climate stats for 2010 are coming in. Here are the highlights, from the National Oceanic and Atmospheric Administration. You can read the full release here.

GLOBALLY:

Smoke, heat in MoscowSurface Temperature: Combined land and water temperatures averaged 1.12 degrees F above the 20th Century average. Tied with 2005 as the warmest since records began in 1880.

Land temperatures averaged 1.8 degrees F above the 20th C. average, the warmest on record. Ocean surface temperatures averaged 0.88 degrees F. above the average, the third-warmest on record.

The year was also the 34th straight year with global temperatures above the 20th Century average.

Precipitation: Global average precipitation was the most on record, but patterns varied widely across the globe. The Pacific hurricane season was the least active since satellite observations began in the 1960s. The Atlantic season was the third-most-active for tropical storms; the second-most-active for hurricanes.

Storms: A negative Arctic Oscillation last winter sent arctic air south, producing record cold and heavy snows in parts of Eastern North America, Europe and Asia. In February, the AO Index was the largest negative reading since records began in 1950. An unusually strong jet stream twisted north into Russia, and then south into Pakistan, contributing to record summer heat in Russia, and severe flooding in Pakistan. The Russian heat wave was accompanied by forest fires that sent thick smoke in Moscow. (Photo)

CONTIGUOUS UNITED STATES:

Surface Temperatures: Surface temperatures in 2010 in the U.S. ranked as the 23rd-warmest onBlizzard Baltimore record, and the 14th straight year averaging above the 20th Century average. Since 1895, surface temperatures have increased at an average rate of 0.12 degrees F per decade.  Twelve states had a record-warm summer (June through August). New York, Philadelphia, Trenton and Wilmington broke summertime records.

Precipitation: The average precipitation in 2010 was 1.02 inches above the long-term average. Since 1895, precipitation rates have increased by an average of 0.18 inches per decade. Seasonal snowfall records were broken in Baltimore, Washington, Philadelphia, Wilmington and Atlantic City. Wisconsin had its wettest summer on record.

Storms: The year ranked among the 10 busiest for tornadoes since 1950, with 1,302 recorded. Minnesota had the most for the first time, with 104 confirmed. Increased precipitation helped shrink drought areas to less than 8 percent of the Lower 48 states. Hawaii experienced near-record dryness for most of the year.

(PHOTOS: Top: Natalia Kolensnikova, AFP Getty. Bottom: Sn Photo by Jed Kirschbaum, Feb. 9, 2010)

Posted by Frank Roylance at 12:45 PM | | Comments (4)
Categories: By the numbers
        

Bel Air tops area snowfall charts

The tallies are starting to come in this morning from Tuesday's snowstorm, and it looks like Bel Air, in Harford County, leads the early returns with one report to the National Weather Service of 4.5 inches of snow.

UPDATE, 1:45 p.m.: Some higher totals have now come in. CoCoRaHS is reporting a 5.5-inch measurement in Whiteford. The NWS map now includes a 5.3-inch measurement from Highland View, and 5.0 inches in Scarboro. All are in northern Harford County. 

So, it looks like the 3-to-5-inch predictions from early yesterday have held up, at least for locations north and east of, say, Loch Raven Reservoir. One to 3 inches is more like it from Washington north and east to Baltimore, with less than an inch south of DC.

The official measurement for Baltimore, at BWI-Marshall Airport, was 2 inches, bringing the season's total to a whopping 3.5 inches.

While it wasn't much, the storm did bring area school officials to cancel classes, or delay openings for an hour or more. Here's the full listing. Just be thankful you're not living in Boston this morning, where the storm is intensifying and preparing to drop up to a foot of snow.

Our snow finally tapered off around 9 or 10 p.m. in most locations. Here is a preliminary rundown on some of the snowfall measurements around the region:

Bel Air: 4.5 inchesBuzzards

Lineboro, Baltimore County: 3.4 inches

Glyndon, Baltimore County:  3.0 inches

New Market:  3.3 inches

Hunt Valley: 3.0 inches

WeatherDeck, Cockeysville:  2.5 inches

Essex:  2.0 inches

Bowie:  2 inches

Columbia:  1.0 inch

Eastport: 0.9 inch

There are more measurements coming in to the CoCoRaHS Network, here. And here is the NWS snowmap.

Forecasters out at Sterling say the cold weather will continue through the weekend before temperatures move back toward seasonal norms. The next precipitation event, on Tuesday, is expected to be rain.

You'll find Eric the Red's port-mortem analysis of the storm on the jump, below.

(SUN PHOTO: Snow buzzards over the WeatherDeck, Frank Roylance)

"[T[here were a few surpises that I figured I should explain.

"First, what gives with the sleet and freezing rain we got?  Well, that was the western low remaining dominant longer than I expected, which allowed warm air surging up the eastern side of the low (where we were) to change the pcp from snow to sleet and freezing rain.This nose of warmer air was several thousand feet above the ground.

"Second, the coastal low gave us next to nothing... it was responsible for a few northward-moving snow showers in the afternoon, but that's about it. The snow that fell in the evening was courtesy of a strong upper-air disturbance associated with the western low that swung thru. Had it not been for that little bonus feature, we would've gotten literally nothing.

"Third... snow did in fact end up being heaviest in northeastern MD, with reports over 4" in Harford County. We rec'd 3" in Jacksonville, and that was a pretty uniform number across most of central and nrn Baltimore County. To the south, it was closer to 1-2".  A far cry from what the Northeast is getting, and certainly qualifies largely as another miss."

Posted by Frank Roylance at 6:55 AM | | Comments (2)
Categories: Winter weather
        

January 11, 2011

In lower 48, only Florida lacks snow today

Thanks to the big snowstorm (for them, not us) that swept across the Deep South yesterday, Florida today is the only state in the Lower 48 that is without snow on the ground.

And since I'm told there is currently 7 inches of snow atop the Mauna Kea volcano, in Hawaii, (and plenty in Alaska, of course), that makes Florida the only state in the union without snow. Here's the map:

National Ice Center

Posted by Frank Roylance at 5:38 PM | | Comments (2)
Categories: Cool pictures
        

Snow predictions for Baltimore are fading

Snow lovers are likely going to be disappointed by this one. Steve Zubrick, science and operations officer at the National Weather Service office in Sterling says warm air is nosing into the region NOAA mapwest of the bay, shrinking the predicted snow totals for the storm.

Accumulation totals for the Baltimore area have dropped from 3-to-5 early this morning, to just 2-to-3 inches by mid-afternoon. Locations south of Baltimore are likely to see a mix of precipitation rather than the all-snow event forecast earlier.

Here's how the new Winter Weather Advisory puts it for locations from Carroll to Arundel:

"ACCUMULATIONS...2 TO 3 INCHES...MAINLY SNOW. A GLAZE OF ICE
  POSSIBLE.

* TIMING...SNOW WILL BECOME MORE STEADY BY EARLY EVENING...AND
  CONTINUE MUCH OF THE NIGHT...ENDING BETWEEN 4 AM AND 6 AM. THE HEAVIEST SNOW WILL BE BETWEEN 9 PM AND 3 AM. AT TIMES SLEET AND FREEZING RAIN OR DRIZZLE COULD BE MIXED IN WITH THE SNOW"

UPDATE, 6 P.M.: for northern Maryland, from the afternoon forecast discussion:

"AMOUNTS OF 1-2 INCHES FORECAST FOR THESE AREAS...WITH HIGHEST TOTALS NEAR MASON DIXON LINE AND AREAS CLOSEST TO COASTAL LOW PRESSURE N/E OF BALTIMORE. FOR METRO DC AND POINTS SOUTH...INCLUDING SOUTHERN MD... NOTHING MORE THAN A TRACE
FREEZING ACCRETION SHOULD OCCUR
."

Light snow was falling downtown at 7 p.m. But, said Zubrick, "For the snow lovers here, this one looks like it will be more north and east of us."

The problem seems to be the late arrival of the low-pressure system coming out of the Ohio Valley. The other low that's been moving up the Atlantic coast today is starting to intensify, Zubrick said. But it will need the Ohio Valley storm to trigger rapid intensification and more snowfall here.

"The surface low coming up the coast is starting to deepen, but it will take the upper-level system from the west to pop that low," he said. Until then, warmer temperatures will seep into Central Maryland from the south and east, and our snow totals will dwindle amid some snow, sleet and freezing rain.

"We really haven't had much snow at all," Zubrick said.

Maybe next time, snow lovers.

Eric the Red has thrown in the towel. Here's his offering at 4:50 p.m. Tuesday:

"Yet again, a forecast goes belly up.  I don't think this storm is happening folks.  The worst-case scenario is unfolding... as the western low remains dominant.  In fact, we're getting snow-sleet mix here at home, indicative that the western low is still very much in control.  The coastal low is a shell... offering little if any moisture to the equation, and it certainly isn't dominant.  We are pretty much relying on some energy with the western low to produce our snow.

"If there's any comfort I take from this infuriating situation, it's that at least I'm not alone in sending out awful forecasts.  Every media outlet and NWS forecast has been on the same page, that we would get our first [significant] snow of the year.  But in the end, I still feel like total crap having these forecasts go awry."

Posted by Frank Roylance at 3:21 PM | | Comments (14)
Categories: Forecasts
        

Flurries, light snow cross the Potomac

You'd think we'd have had enough after last year's relentless winter, which broke Baltimore snowfall records at 77 inches before it ended. But at least some Marylanders are watching the skies for this next Rush hour snow Baltimorelittle storm as if they hadn't seen snow in years.

"Light flurries started in Annapolis," Andrea emailed me a few minutes ago.

"Flakes have started falling in DC 8)" reported Colleen.

Yes. The SNOW is coming. Washington Reagan National, Quantico and Andrews Air Force Base are all reporting light snow. There are flurries at Dulles and Fort Belvoir. Pax River NAS reports sleet. Here's the radar loop.

UPDATE, 2:45 p.m.: Steady snow now in downtown Baltimore. Let the rush hour begin.

UPDATED UPDATE, 3 p.m.: Never mind.

The forecast here remains about the same. There is a Winter Weather Advisory up for almost the entire state, effective from 4 p.m. this afternoon until 6 a.m. Wednesday.

UPDATE, 1:50 p.m.: The accumulation forecasts have slipped some this afternoon. The 4-5-inch bands on the map have disappeared. Two to 4 inches seems to be the rule for the Baltimore area. One to 3 inches are more likely to our south and west.

No flakes out my window at Calvert and Centre, but the barometer at The Sun's weather station has fallen off a cliff, signaling the approach of low-pressure systems along the coast and from the Ohio Valley. They will merge off the coast and intensify, setting up the rest of the Northeast, and especially southern New England, for a big snowstorm.

(SUN PHOTO: Doug Kapustin 2007)

Posted by Frank Roylance at 1:11 PM | | Comments (5)
Categories: Winter weather
        

Central Maryland due 3-5 inches tonight

Central and Southern Maryland should expect 3 to 5 inches of snow tonight, with the heaviest amounts close to the Chesapeake Bay, falling off to the west and south. Much of the Eastern Shore is being told to expect 1 to 3 inches, except along the Atlantic coast, where mixed precipitation will likely hold accumulations to little or none.

UPDATE, 10:45 a.m.: Baltimore, Howard and Harford county Schools will close an hour early Tuesday in anticipation of the snow. Anne Arundel and Kent schools will close two hours early. Here's the link. The National Weather Service has also updated its forecast snow map. The new one is now displayed below. It shows a much-diminished area of 4-5-inch accumulations (purple). Snow estimates in their Winter Weather Advisories have not changed.

The National Weather Service has issued Winter Weather Advisories for almost the entire state, calling for the snow to move in from the south and west. Forecasters believe it will begin snowing between 3 and 5 p.m. in Northern Virginia, Washington, D.C., Frederick, Montgomery and PG counties. Flakes should turn up between 4 and 6 p.m. east of there, including Westminster, Baltimore, Columbia and Annapolis.

Eric the Red, a professional forecaster from Baltimore, tells us the latest model runs suggest an earlier start for the snow:

"Latest radar, satellite, and model data has snow developing around midday, with an inch or so possible in the DC area during the eve rush, with lighter amounts in Baltimore due to a later start.  The period of heaviest snow will occur between 7 and 10 pm, and perhaps linger til midnight in nrn and northeast MD."

NWS new snow mapNWS forecasters expect temperatures to hold in the lower 30s, so the event is likely to remain all-snow. 

The fact that Sterling issued a Winter Weather Advisory rather than a Winter Storm Warning, means that they don't believe accumulations will top 5 inches in the Baltimore area. But their morning forecast discussion indicates their confidence in that conclusion is not ironclad:

"IT WOULDNT TAKE MUCH MORE TO RAISE THE BALTIMORE AREA INTO WINTER STORM WARNING CRITERIA. IF FRONTOGENETIC FORCING IS STRONGER AND DECENT BANDING OCCURS AND...OR IF PHASING [MERGER OF THE TWO STORM SYSTEMS] OCCURS SOONER...THEN HIGHER SNOWFALL TOTALS MAY RESULT. DO NOT HAVE ENOUGH CONFIDENCE IN THAT RIGHT
NOW...WHICH IS WHY ADVISORIES WERE MAINTAINED."

(I know the NWS map above is hard to see. Here's a link to the source page. Best I can do.)

Once the storm passes by, we won't be entirely out of the wintry weather. Colder-than-average temperatures and stiff winds will keep us in the icebox:AccuWeather.com

"WESTERLY/NORTHWESTERLY FLOW WILL QUICKLY INCREASE ACROSS THE AREA WEDNESDAY WITH GUSTS EASILY INTO THE 30 TO 35 MPH RANGE THROUGH THE DAY. WITH MAX TEMPS IN THE MID 30S...WIND CHILLS ARE EXPECTED TO BE IN THE TEENS IN THE MORNING AND NOT GET ABOVE THE MID 20S IN THE AFTERNOON." 

Elsewhere, the Northeast is bracing for the same storm, in spades. AccuWeather.com is saying Eastern Massachusetts could see 12 to 18 inches, with much of New Jersey and New York City due 6 to 12.

Here's how close we are to the Winter Storm Warning area, in purple, with 5 to 8 inches forecast in Philly, 4 to 6 in Dover.  

UPDATE  9 a.m.: Eric the Red has popped in, after a new look at the models. Something there has caught his eye:

"The off-cycle 06z run (1 am) of the WRF/NAM has changed its story dramatically.  It has the coastal low intensifiying faster and farther south, and is now upping the total to a half inch of liquid or more.  This would be at least 5" of snow, with higher totals across north-central and northeastern MD. 

"I am not ready to jump on this just yet, cos the same cycle run of the GFS has actually backed off.  But early morning visible satellite imagery is a wee bit disturbing, and radar shows the pcp [precipitation] breaking out sooner than expected.  I will keep you posted."

UPDATE: 10:45 a.m.: "Seeing another set of model data has set the record straight.  Last night's "uh oh" fcst from the WRF was just a blip, and it has gone back to the idea of 2-4" for most of the region.  There may be higher totals in northeastern MD, but most areas are looking at a quick shot of 2 to 4 inches.  I suspect DC may come in a tad lower, with 1-3". 

Posted by Frank Roylance at 6:48 AM | | Comments (14)
Categories: Forecasts
        

January 10, 2011

Want more snow? Get on any interstate and drive

It doesn't really matter much which way you go. If you want more snow out of this storm, you'll need to get on I-95 and head northeast. Or south. Or I-70 and west. Central Maryland appears to be in a bubble again.

If the AccuWeather.com forecast map below proves correct, we're in for 1 to 3 inches of snow west of the AccuWeather.comChesapeake tomorrow and tomorrow night. The real heft with this storm is headed for cities up the line. Philadelphia would get 4 to 8, and snow-weary New York City, most of Southern New England, including Boston, are in for 6-12 inches.

That's because the twin systems churning across the country today are expected to merge, or "phase" to our north and east, intensifying the low over the Atlantic and sweeping more snow onshore just to our north and east.

If you decide to head south, AccuWeather forecasters would advise setting your GPS for western North Carolina, where they're expecting 3 to 6 inches.

Or, you could head west. Garrett County is under a Winter Storm Watch calling for 6 inches or more as the Plains component of this wintry episode moves in. Or just about any direction - even east.

Take your pick of winter wonderlands outside our protective bubble that AccuWeather.com says are due for 3 to 6": Cleveland, Pittsburgh, Erie, Buffalo, Scranton, Allentown, Reading, Wilmington, Dover, Charleston, Albany, Binghamton, Syracuse, Elmira, Rutland, Concord and Augusta.

Prof. Jeff Halverson, at UMBC, says this just isn't our snowstorm:

"We have two pieces of energy - one approaching from the Ohio Valley, the other working its way northeastward off Hatteras. Eventually, the energy will transfer to the coastal low, but  that won;t happen anywhere near Baltimore.

"The system will be somewhat disorganized and in a transitional state as it transits our region. We'll be caught between two areas of low pressure, both competing for moisture and energy. For us, this is not the classic snowmaker scenario by any means."

 

One other thing: The student meteorologists at Foot's Forecast have issued their winter weather predictions, which are more or less in line with everyone else:

"A general 2-4” snowfall in the Baltimore-Washington area, with higher amounts farther east and south. Some isolated locations along the I-95 corridor may reach 5” while lesser amounts of 2-3" are expected from Northern Virginia to Frederick and Carroll Counties.

"East and north of I-95 from Cecil County, MD to the Bayshore; counties of Eastern MD and Delaware as well as eastern Pennsylvania are likely to reach NWS Winter Storm Warning criteria with amounts reaching or exceeding 5".

"We anticipate the maximum snow intensity may be reached around midnight across the region and could be falling at the rate of one inch per hour, and diminishing by daybreak. It is possible that a few flurries will remain until mid-morning."

 

Posted by Frank Roylance at 2:07 PM | | Comments (1)
Categories: Forecasts
        

Storm shifts to Tues. P.M.; 5 inches or less due

Snow chances for Tuesday in Central Maryland have now reached 100 percent, and forecasters at the National Weather Service have issued a Winter Storm Watch for Central and Southern NWSMaryland, as well as much of the Eastern Shore.

UPDATE: 3 p.m.: The latest Winter Storm Watch out of Sterling has the snow starting in the late afternoon or early evening Tuesday. No problem for the morning rush. And light snow in the evening may spare us a really bad commute home. Earlier post resumes below.

The Watch means snow accumulations of 5 inches or more are possible within 12 hours as the snow falls, but most areas would likely see less. The snow totals will fall off sharply from east to west. Carroll and Howard counties are at the western edge of the Watch area.

A lesser Hazardous Weather Outlook statement has been issued for the western counties to Allegany, calling for "accumulating snow." Garrett County is under a Winter Storm Watch calling for 6 inches or more.

Forecasters at the Baltimore-Washington forecast office in Sterling, Va., say they expect the snow to begin falling at BWI-Marshall airport a bit later than previously stated - around mid-day Tuesday or during the early afternoon. It is likely to continue through Tuesday night.

Daytime highs during the storm will be in the low 30s. The precipitation is expected to be all snow in the Baltimore region, but could become mixed with sleet in Charles, Calvert and St. Mary's counties in Southern Maryland. The Lower Shore should expect a mix of rain, sleet and snow, with little or no accumulation, forecasters said.

The snow comes as two storm systems approach the region. The largest system is hitting much of the South today with snow, ice and rain. It is expected to move east and emerge off the Carolina coast tonight. That one will be sending increasing moisture into the region from the Gulf and from the Atlantic.

The second low is approaching from the Great Plains, with the center passing to our north on Tuesday, putting Central Maryland in between the two systems.

AccuWeather.com says the twin storms will merge to our northeast and hit New England especially hard after whitening the mid-Atlantic corridor:SNow map for Sunday 1/9/11

"Plenty of cold air will remain in place to support snowfall along much of the heavily populated I-95 corridor in the Northeast, while some mixing, including treacherous ice will occur farther south through the mid-Atlantic Coast. This means that heavy snowfall with amounts of up to a foot could slam a corridor from perhaps as far south as New York City and northern New Jersey to Boston and eastern Maine."

"Philadelphia also looks like it is line for plowable snow that will disrupt travel, while the Baltimore-Washington, D.C. corridor may only get a couple of inches of snow from the storm. It should be noted that the storm track is still not set in stone. A wobble in the storm's track by only 50 miles can make a major difference in snow totals for the big Northeast cities."

The map at right shows the snow cover for the continent on Sunday. You can see the new snow in Oklahoma, Arkansas and Mississippi from the developing southern storm.

Eric the Red, a professional meteorologist in Baltimore, has chimed in with this:

"Early morning data has the phasing occurring just in the nick of time to give the region 2-4" ... with the heavier snow across northeast MD. The WRF/NAM [models]  has the snow arriving in DC about 4-7 p.m. on Tues., and shortly after 7 [p.m.] in Baltimore. This would be ideal, giving everyone a chance to get home.

"The WRF also has a quick burst of moderate to perhaps even heavy snow during the late evening hours, and then cuts the [precipitation] off abruptly between 1 and 4 am Weds morning.

"Still have other model data to come in, but the early guidance supports 1-3" south and west of Baltimore (even in DC) ... while 2-4" from Baltimore and points north and east."

Posted by Frank Roylance at 7:01 AM | | Comments (19)
Categories: Forecasts
        

January 9, 2011

Tues. snow chances 90 pct; amounts light

It looks quite likely now that Central Maryland will see accumulating snow on Tuesday. Forecasters out at Sterling give it a 90-percent chance. They still aren't able to settle on accumulations, but they are leaning toward a scenario that would drop less than 6 inches on the region. Maybe just an inch or two.

And while that doesn't sound like much after living through the winter of 2009-2010, it would be NWSthe first significant storm of this season, and it would begin in time to complicate the morning rush hour. And, given what happened last week when we had less than an inch, it would likely affect school openings across the region.

The NWS is watching as low pressure in the Gulf of Mexico makes its way toward the South Carolina coast. Complicating the forecast is the progress of another low developing to our west. Sterling does not believe the two will merge, or "phase," until they have gone by to our north and east. That would limit the snowfall here:

"IF THIS SCENARIO HOLDS TRUE...THE MID-ATLANTIC...AND IN
PARTICULAR OUR CWA [FORECAST AREA]...WILL REMAIN SANDWICHED BETWEEN THE TWO SYSTEMS AND EXPERIENCE LIGHT THOUGH ACCUMULATING SNOW FOR MAJORITY OF EVENT.

"USING ALL AVAILABLE MODEL GUIDANCE...QUITE CHALLENGING TO FIND A SINGLE
MEMBER RUN THAT PROJECTS MORE THAN 6 INCHES IN THE CWA
. SEVERAL MODELS SUGGEST MIX/CHANGE TO [SLEET OR FREEZING RAIN] ACROSS SOUTHEASTERN ZONES...SO HAVE
INCLUDED [WINTRY] MIX FOR LOWER SOUTHERN MD TUE AFTERNOON.

"BY LATE TUES...LOW PRESSURE EXPECTED TO PASS DELMARVA AND QUICKLY BECOME DOMINANT
SURFACE CYCLONE TUES NIGHT...RAPIDLY STRENGTHENING. DRY SLOT SHOULD ERODE
PRECIP FROM SW-NE DURING THE NIGHT...THO WILL HAVE TO WATCH FOR SOME
WRAP-AROUND MOISTURE/PIVOTING OF BANDING BACK TOWARD NE MD. ALSO...UPSLOPE SNOW SHOULD INCREASE TUES NOGHT ACROSS WEST-FACING SLOPES OF ALLEGHENY HIGHLANDS...WHICH AccuWeather.comMAY CONTINUE ... SEVERAL DAYS."

AccuWeather.com is saying the storm could be disruptive, especially if the track of the coastal low stays a few miles closer to the coast (map, left):

"Plenty of cold air will remain in place across the Northeast following the latest rounds of snow, laying the groundworks for a few to several inches of snowfall for the major Northeast cities if the next storm hugs the coastline Tuesday into Wednesday.

"Travel disruptions both on the ground and in the air are possible, as well as school and activity delays and cancellations." 

The Weather Channel is focusing on the snow and ice across the Deep South this weekend. By Tuesday, their forecasters say, the coastal low will move offshore, and the western storm will move into the picture. But they don't seem much concerned with the impacts here:

"Tuesday, a separate storm producing snow in the Midwest and the storm heading up the East Coast will begin to merge. Snow will develop across the Mid-Atlantic. The storm will rapidly strengthen as it heads from off the Mid-Atlantic Coast to off the New England coast Tuesday night and Wednesday. Heavy wind-driven snow is possible across eastern New York and New England with some foot or greater accumulations possible."

Posted by Frank Roylance at 4:35 PM | | Comments (3)
Categories: Forecasts
        

Monday's date is a palindrome

FROM TODAY'S PRINT EDITIONS:

CalendarMonday is Jan. 10, 2011. In numerical notation, it’s 1-10-2011, the first of two “palindrome dates” in the new year – dates that can be read the same, backwards or forwards. The next one will fall on Nov. 2, 2011, or 11-02-2011. After that, the next year with two palindrome dates is 2021, on Jan. 20 and Dec. 2. That’s the last year in this century with two palindrome dates in the month-day-year format, according to Prof. Aziz S. Inan, at the University of Portland.

(SUN PHOTO: Frank Roylance)

Posted by Frank Roylance at 12:01 AM | | Comments (2)
Categories: From the Sun's print edition
        

January 8, 2011

Tuesday snow more likely, amounts still uncertain

The chances for accumulating snow in Central Maryland late Monday and Tuesday have inched upward a bit, now set at 70 percent for Tuesday, according to forecasters at the National Weather Service.

But just how much snow is likely remains unclear. The problem is the difficulty of predicting whether, where and how two separate storm systems might come together in the region. If the timing is right, and the two systems "phase," we get more. If they straggle through separately, we get less. The tracks matter, too, as the more southerly storm could drift off the Southeast coast and out to sea before giving us much trouble.

AccuWeather.comThe NWS forecasters out at Sterling say a 30 percent "chance" of snow late Monday will evolve to a 70 percent "likely" snowfall Tuesday and 60 percent Tuesday night.

For now, they don't think the more northern storm - riding the northern "polar" jet stream out of the Great Plains and crossing our region Tuesday - will phase with the storm spinning up over the Gulf until they've passed off the Atlantic coast:

UPDATE, 8 a.m. Sunday:

"IF THIS PHASING OCCURS PAST THE MID ATLANTIC...THIS WILL LIKELY PREVENT
A SIGNIFICANT SNOW EVENT ACROSS THE CWA [FORECAST AREA] AND THIS WOULD LIKELY BE
MAINLY AN ADVISORY SITUATION TUESDAY AND TUESDAY NIGHT.
HOWEVER...IF THE PHASING OCCURS SOONER...THEN PORTIONS OF THE CWA
COULD SEE A MORE SUBSTANTIAL SNOWFALL /ASSUMING NO MIXING...WHICH
COULD OCCUR ACROSS SOUTHERN MD/.

"RIGHT NOW WE ARE LEANING TOWARD
THE FORMER IDEA OF PHASING OCCURRING NORTHEAST OF THE MID ATLANTIC
COAST...BUT THIS IS CERTAINLY NOT WRITTEN IN STONE GIVEN THE
COMPLEXITY OF THE SYNOPTIC SITUATION SO PLEASE STAY TUNED
."

Meanwhile, AccuWeather.com hasn't pushed its predictions past Monday for the mid-Atlantic (updated map). But their assessment through Monday shows some nasty weather ahead for the South. And we would seem to be next in line.

Saturday morning's snowfall didn't amount to much in Central Maryland, although McHenry, out in far western Garrett County saw 5 inches. Greensboro, in Caroline County reported 2.7 inches. A few spots saw 1 to 2 inches, but most of the rest of us had less than an inch.

Posted by Frank Roylance at 9:44 PM | | Comments (1)
Categories: Forecasts
        

Death Valley gets a drink

FROM TODAY'S PRINT EDITIONS:

Death Valley wildflowersLeonard Frankford writes from Pikesville: “With all the recent rain in southern California, I was wondering if any of it has reached Death Valley, which is normally so dry. If so, how much rain did it get?”  Precious little. The total for December at Death Valley was 0.86 inch. Most of that (0.72 inch) fell in a four-day stretch from Dec. 20-23. On the other hand, their average December rainfall is only 0.19 inch. So, at four times the norm, it really was a soaking.

(GETTY IMAGES: David McNew, 2005)

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: From the Sun's print edition
        

January 7, 2011

Another dusting tonight, more worries for Tuesday

Well, that wasn't such a big deal, was it? The dusting didn't even cover the grass below the WeatherDeck in Cockeysville. (Some local accumulations amounts on the jump, below.)

Mother Nature will get another chance tonight as another moisture-starved disturbance and cold front slip by. But the next (first?) significant snow of the season may have to wait until Tuesday.

Dusting of snowForecasters out at Sterling are describing tonight's setup as very similar to last night's. A little clipper-type disturbance is expected to spin around a low centered over the Great Lakes, bringing us another dusting of snow. It would begin after midnight tonight in the Baltimore area, and end sometime before lunch on Saturday. 

They (the NWS) are predicting less than a half inch overnight, and about the same after daybreak. Eric the Red, a professional forecaster in Baltimore, thinks it may be a bit heavier and more widespread than last night's snow, and the one after Christmas (photo).

"I think it's prudent to plan on seeing 1-2" of snow tomorrow. However, little if any snow is once again expected south of D.C."

AccuWeather.com has us in the 1-3 inch-range (snow map, below).

With all the salt on the roads this morning - my car was really crunching through it - I doubt there AccuWeather.comwill be much to worry about. But it's always a good idea to slow down when snow is falling and the temperatures are below freezing.

Once those snow showers and the next cold front blow by, skies will clear later on Saturday. And we can expect a sunny - but cold - day on Sunday. Highs will stall in the mid-30s - well below the norms for this time of year at BWI-Marshall. The overnight lows Saturday and Sunday nights will be in the low 20s.

Baltimore health officials have extended their Code Blue Health Alert through Sunday.

The next wintry weather would come Tuesday. The models are toying with a storm forecast to develop over the Gulf states. It would move to the northeast, while another disturbance over the Plains states moves east. The computers haven't quite settled yet on how the two will interact.

AccuWeather.comWhile the algorithms battle it out, the NWS is still calling for "a chance of snow," put at 30 percent for Tuesday and Tuesday night. Eric the Red is more confident:

"I think you can go ahead and put that storm on the 'likely' list. Looking more and more like our first, significant winter storm of the season."

UPDATE, 2 p.m.: New from Eric: "The first low will move out of the Gulf and along the coast, while the second will trail to the west ... The two are expected to phase into one, big, happy snowmaker along the Mi-Atlantic or Northeast coast.

"If, when, and where this phasing occurs will determine whether we get 2-4" of snow or 6-12."  ... The Tues. storm will likely start during the day on Tuesday, setting the table for a disastrous afternoon commute. The [precipitation] will linger into Tues. night and end on Weds. Given that this is still 4 days away, this is very prelim." 

And AccuWeather.com is already looking for a "major winter storm," and "heavy" snow in most of Maryland. (Map, above.)

(SUN PHOTO: Algerina Perna, Dec. 26, 2010)

Here are some snow totals from our Friday morning dusting.

Frostburg:  3 inches

Bel Air:  1.3 inches

Kingsville:  0.6 inch

Baldwin:  0.5 inch

Emmittsburg:  0.5 inch

Jacksonville: 0.4 inch

Odenton:  0.3 inch

Gaithersburg: 0.2 inch

Here's more.

 

Posted by Frank Roylance at 11:54 AM | | Comments (3)
Categories: Forecasts
        

A "smile in the sky" over Baltimore

This morning's email included a wonderful photo, and this note from Kirstie Schraffenberger:

"I was with some friends down at the Inner Harbor last Wednesday afternoon when my toddler daughter in her stroller spotted what I don't think anyone else in the city noticed since we never bother to look straight up: these back-to-back double rainbows directly overhead.

"I've never heard of this phenomenon, and it was a sunny day with no recent rain. I thought you'd like to see this, and if you have any explanation that you have the time to share, I'd love to hear it!  - Sincerely, Kirstie Schraffenberger"

You're right. Too many of us rarely if ever look up. And that means we miss many striking and memorable phenomena such as this one.

Circumzenithal arc BaltimoreThere appear to be two things going on in this photo. The first arc - the one that looks like (and is often called) a smile in the sky, is what meteorologists call a "circumzenithal arc."  The "circum" part means "around," and the "zenithal" part refers to the "zenith." That's the point in the sky directly overhead.

Circumzenithal arcs are caused by the refraction of sunlight by ice crystals in the sky. It's a bit like the refraction by raindrops that create rainbows. But these are caused by horizontally aligned ice crystals. They are rarely more than a quarter of a full circle, and the arc curves away from the sun. And, if it were a complete circle, the zenith would be at the center. They're not all that rare, apparently, but they are rarely noticed, for the reason you cite - few of us ever look straight up.

For circumzenithal arcs to appear, the sun needs to be lower than 32 degrees above the horizon. The afternoon sun in late December would probably be well within that range.

The other arc is probably what's called a "supralateral arc." The cause is the same - refraction and reflection of sunlight within the ice crystals. But the geometry is different. If you could extend the supralateral arc, it would form a circular halo or bow around the sun. It could also be part of what's called a 46-degree halo. Hard to tell them apart sometimes, apparently. 

Supralateral arcs come into contact with circumzenithal arcs when the sun is between 27 and 32 degrees above the horizon. 

That's my take on it, anyway. I'd welcome any other thoughts readers might have. Your picture is one of the best I've seen of this phenomenon. Thanks so much for sharing it. Here's more on the topic.

Posted by Frank Roylance at 10:53 AM | | Comments (2)
Categories: Phenomena
        

Merry Christmas to "Old Calendarists"

FROM TODAY'S PRINT EDITIONS:

Merry Christmas to anyone of the Eastern Orthodox faith still among the “Old Calendarists”Orthodox Christmas using the Julian calendar. By that reckoning, today is Dec. 25. The “modern” Gregorian calendar was promulgated in 1582 by Pope Gregory XIII. The update was needed to keep the Western church calendar in step with the seasons by imposing a new leap year system. Most Western countries had adopted it by the 18th century. The Julian calendar has now fallen 13 days behind the Gregorian. 

(AP PHOTO: Mikhail Metzel, 2010)  

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: From the Sun's print edition, Sky Notes
        

January 6, 2011

Light snow could affect Friday morning rush

The predictions are pretty skimpy - an inch or less in most places across Central Maryland Friday morning. What's got the forecasters' attention this morning is the timing. The dusting is due to start after 4 a.m., making it something to consider during the Friday morning rush hour in Baltimore.

Forecast snow totalsAnd because the criteria for issuing a Winter Weather Advisory in the metro areas for wintery weather at the rush hours are lower, we could see the advisories before the day is out today.

It's a pretty complicated forecast scenario. But it boils down to this: A coldSnow chances 70 pct front approaching from the west will bring a chance - put at 70 percent now - for snow, beginning before dawn on Friday. Less than an inch is expected at BWI and much of the state, (light blue on the map), a bit more than an inch north and east of the city (dark blue).

Here's a better look at the forecast map.

That event is expected to last no more than 3 to 6 hours. Snow showers during the day Friday could add another few fractions of an inch before ending around lunchtime, forecasters said.

More light snow is possible Saturday morning as another cold front slips by, but the chances drop to 30 percent.

The prospect of snow and cold overnight temperatures has prompted Baltimore City health officials to declare a Code Blue Health Alert for Friday, opening the city's shelters for extended hours. Outreach workers will also be checking on vulnerable residents.

The forecast calls for even colder weather after the cold front passes on Friday. Lows are expected to drop to near 20 degrees each night through the weekend.

City Health Commissioner  Dr. Oxiris Barbot issued the following statement:

"Baltimore City recorded two deaths last month in which hypothermia was a noted factor. Both individuals were seniors found indoors but without heat. These preventable deaths remind us of the importance of looking out for neighbors, especially the elderly and medically frail who live alone, and those without heat."

Forecasters are still watching for the development of another storm predicted by the models. That one could reach us by Tuesday of next week. The chances are set at 30 percent for now. The forecast track sends it close, or just south of our area. It's way too early to put much stock in the trajectory, but it's a heads up for anyone planning to travel during that period. Keep an eye on forecasts. 

The student forecasters at Foot's Forecast see some chance for a bit more snow from the Friday event:

"The snow squall line associated with the cold front will deliver a quick coating to 2” of snow in the Mid-Atlantic. Snow is likely to impact the morning commute on Friday 1/7 resulting from brief periods where some roads, bridges and overpasses become snow-covered.

"This cold front will eventually become an inverted instability trough in the Northeast. A more southern position of this instability trough may bring higher accumulations to the Northern Mid-Atlantic."

Here's AccuWeather.com's take on it.

UPDATE, 6 p.m.: Prof. Jeff Halverson, from UMBC, has checked the latest model runs on the Tuesday storm. Here's his take:

"While today's ECMWF takes the coastal system well to the south and out to sea, the GFS medium range bombs out a low off Hatteras Tuesday, with a swath of 1/2&3/4 liquid over central MD - that would translate into 10+ snow. Jet stream dynamics look impressive. The AVN forms a low off Hatteras, but it looks to be further east and south than the GFS.

"Once again, it's too early to beat the snow drum, and time will tell to see if and how the models line up on this one. Two strikes against a heavy snow scenario include the fact that the NAO is predicted to become positive over the next week or so, and La Nina is generally a heavy-snow killer for the Mid Atlantic.

"But, the metro regions (DC and Balt) did skirt very close to a major snowstorm the day after Christmas. If coastal low tracks show this type of consistency, will this winter season evolve into a series of chilly near misses?"

Posted by Frank Roylance at 11:08 AM | | Comments (3)
Categories: Forecasts
        

Md. astrophotog captures Quadrantid meteor

Mike Hankey, an amateur astrophotographer in Freeland, in north-central Maryland, set up his camera Tuesday morning to capture images of some of the Quadrantid meteors.

He only managed to snag one, but it was good one. He stitched a series of stills into an animation that includes the meteor and the glowing trail that he said persisted for more than 10 minutes.

Quadrantid meteor animation

Mike also captured the fireball at the top edge of the field of view on his security camera.

 

Posted by Frank Roylance at 10:05 AM | | Comments (1)
Categories: Cool pictures, Sky Notes
        

Rise and shine! Sunrises now getting earlier

FROM TODAY'S PRINT EDITIONS:  

Sunrise BaltimoreCheer up! Sunrise today was a few seconds earlier than yesterday. Our daylight hours are now increasing at both ends of the day. That’s because Wednesday morning’s sunrise was the latest of the year – 7:27 a.m. for Baltimoreans. It was a bit earlier at the beach, later at Deep Creek. Sunsets have been advancing since Dec. 8. By month’s end, we will have added 12 minutes of sunlight in the morning, and 29 minutes in the afternoon. Can spring be far behind?

(SUN PHOTO: Jed Kirschbaum, 2007)

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: From the Sun's print edition, Sky Notes
        

January 5, 2011

Bird deaths: Did NWS radar capture startled flock?

Weather radar in Little Rock, Ark. may have captured an image of a flock of birds as they rose from nighttime roosts near Beebe, Ark. on New Year's Eve. Thousands of redwing blackbirds were later found dead on the ground nearby.

Such radar images of bird flocks are not unusual. Weather radar sites near the Chesapeake Bay in Maryland and Delaware sometimes capture the radar reflections of flocks of birds as they rise into the sky at sunrise on summer mornings.

Little Rock radarLast night, Steve Zubrick, the science officer out at the National Weather Service forecast office in Sterling, Va., sent me a link to a radar image recorded beginning at 10:21 p.m. Central Time in Little Rock. That's about a half hour before reports began coming in about dead birds falling from the sky in Beebe.

The loop shows rainstorms moving away to the north and east of the radar. But at a spot about 25 nautical miles northeast of the radar, an unusual reflection appears, expands and moves off to the southeast with the prevailing winds. It's the green blob on the still radar image above.

"Could these returns be birds disturbed from the nightly roosting sites?" Steve asks.

"Given what was on radar...just a few light showers moving NE and examination of surface obs within 30nm of this area showed nothing unusual (no high wind gusts, eg). There were a few positive lightning strikes about 50-55 nautical miles to the SE over Arkansas County around 0430 UTC. Positive lightning strikes carry much more current then negative strikes...and have a much bigger "boom" then negative strikes. Still, they were located 55 miles away...although it would not be entirely impossible other lightning (non-cloud-to-ground) could have occurred.

"But I don't have any data that could show that (i.e., there is no lightning detection network that I know of in that area that would pick up the "total" lightning (e.g., within cloud or cloud-to-air)

"I'd say there is not a meteorological explanation. Exploding fireworks sounds like the most plausible...given the time of year...New Year's Eve...and that many folks like to shoot off fireworks to celebrate the New Year."

Posted by Frank Roylance at 12:17 PM | | Comments (19)
Categories: Cool pictures
        

Snow chances at week's end, early next week

The snow watch continues this week as colder weather settles in. None of it is alarming. But forecasters out at Sterling have upped the chances for snow showers Friday to 50 percent. And there is a new chance for more snow posted now for Monday into Tuesday.

High temperatures for the rest of the 7-day forecast period remain in the 30s, with lows deep in the 20s. So this is going to feel pretty wintry for Baltimore. The first chance for snow - showers, they're calling it - comes Thursday night, with the odds set at 40 percent.

AccuWeather.comFriday's odds kick up to 50 percent, but they're still calling it snow "showers." The definition of snow showers is intermittent snow falling from convective clouds (rather than widespread stratiform clouds). That makes them of short duration. They may or may not leave some slight accumulation on the ground.

These showers, if they arrive, come with the arrival of a cold front that's forecast to move through the mid-Atlantic late Thursday into Friday. The low driving the front - and the real snowstorm - will stay to our north and east, with AccuWeather predicting "disruptive" snow for southeastern New York State and parts of New England.

Here's what Eric the Red is anticipating for Thursday into Friday: "DC/nrn Va.: Nothing. Between DC and Baltimore:  A dusting, perhaps an inch. North and East of Baltimore: 1-3", with low end closer to the city.

"Given the amount of energy that will accompany the system, I think it's safe to put out a prelim heads up for a dusting to perhaps an inch or two of snow for Thurs night into Friday morning. I don't know about you, but I'm headed to Safeway."

After a brief period of higher pressure and clear skies Saturday and Sunday, there's another system due that could bring more snow Monday night into Tuesday. Not much chatter about that yet. But Eric the Red thinks it might be our first decent snowstorm of the season:

"If I were a gambling man, I'd place my bet on our first significant winter storm for the interior Mid-Atlantic. I mean, really, they ALL can't miss us, right?!

"I have a hard time buying the to-our-west track, cos the northern Atlantic would argue against that; the block tends to cause storms to form/track along the coast, or if anything, too far offshore (i.e. Christmas week).

"As it stands now, the timing of this whole thing looks to be Tues into Weds."

Posted by Frank Roylance at 10:12 AM | | Comments (2)
Categories: Forecasts
        

January 4, 2011

Colder weather ahead, but snow a longshot

Looks like Central Maryland will be sliding back into a colder weather pattern for the rest of the week and on through the weekend. The good news would seem to be that the snow icons on the NWS forecast apperar to be mostly precautionary. Nobody is hyping this little system as a real Cold January in Marylandsnow threat, unless you're headed for New England this weekend.

Today's forecast high for BWI is 44 degrees, but at noon it's only 36 downtown. The forecast from Sterling calls for these sunny skies and clear, starry nights to continue for a bit longer. (It was a great night for watching the Quadrantid meteor shower, but I confess a warm bed had a stronger appeal.)

If we do make the 40s today, it will likely be the last we see of that territory for a while. There's a dry cold front due through the mid-Atlantic late today, and temperatures tomorrow will hold in the 30s. Overnight lows will fall to the mid-20s at best.

AccuWeather.com's Joe Bastardi says the first few weeks of January could be the coldest for much of the northern states since 1985. So much for our January warm-up.

High pressure will dominate through Wednesday. After that, forecasters have a series of clipper systems in store. They're expected to drop out of Canada on Thursday and boost our snow AccuWeather.comchances to 20 percent late Thursday and 30 percent on Friday and Friday night.

That said, the morning discussion from Sterling says little to be alarmed about: "Models keep most of the forecast area dry, except along the western-facing slopes and across the Mason-Dixon line."

AccuWeather.com has a coastal low developing from the clippers' energy off the mid-Atlantic coast (map). But their forecasters keep the storm's impact well to our north, with the greatest risk in northern New England as the storm heads that way on Saturday.

Eric the Red has few concerns about our weekend: "We may see some flurries or light snow on both days [Friday and Saturday]. I don't think we need to race out to Wegman's for this one, though."

But he has begun to note models that project something more next week. Maybe snow, certainly cold:

(SUN PHOTO: John Makely, Annapolis, January 2003)

"In the long term, the blocking high which briefly went away around New Year's eve is back and here to stay. That means money-in-the-bank cold. As new members of this list are rapidly figuring out, money-in-the-bank snow is a little harder to come by.

"As long as we have the blocking high (a negative NAO), then our chances for snow are better than average. It's just getting the pieces to line up. Just hasn't happened yet."

"Models are offering a storm for next week... and lo and behold, they also have a high to our north.  So this bears watching for sure."

Posted by Frank Roylance at 11:56 AM | | Comments (0)
Categories: Forecasts
        

January 3, 2011

Mild Sunday, but no record

The weekend's mild temperatures sure provided a welcome break from the otherwise pretty cold days of December - the coldest since 2000. They almost had me out there raking the last of the autumn leaves. But ... nah.

The mercury at BWI-Marshall Airport climbed to 59 degrees on Saturday, and 60 on Sunday. We Mild January day in Baltimorereached 59.5 degrees here at The Sun's weather station, at Calvert and Centre streets. It was a reminder of the first day of December, which hit 62 at BWI before cold winter weather finally struck.

But January highs in the 60s aren't all that rare in Baltimore. We reached the 60s in January as recently as last Jan. 25, when it was 66 degrees - in the middle of the snowiest winter on record here.

The records for the 1st and 2nd are 67 degrees (2005) and 71 degrees (1876), respectively. We've reached the 70s on 22 of the 31 dates in January. The record high for Baltimore in January, at least since they started keeping records in 1871, was 79 degrees, on Jan. 26, 1950.

But let's not forget where we are on the calendar. January's daily cold records range from minus-7 degrees (on three January dates), to 8 above zero, on Jan. 7, 1988. The average snowfall for this month in Baltimore is 7 inches. The snowiest January day was Jan. 28, 1922 (23.3 inches). And the snowiest January was in 1996, with 32.6 inches.

(SUN PHOTO: Amy Davis, Jan. 6, 1997)

Posted by Frank Roylance at 11:36 AM | | Comments (0)
Categories: By the numbers
        

Promising skies for Quadrantid meteors tonight

High pressure and clearing skies provide some hope that Marylanders will get a look at the annual Quadrantid meteor shower tonight.

The Quadrantids are one of the best showers of the year. They'd be more popular than the Perseids in August if it weren't so darn cold out there. And the fact that they occur this year simultaneously with the New Moon means moonlight will not dim the view.

According to Guy Ottewell's Astronomical Calendar for 2011 (has yours arrived yet?), the Quadrantid radiantQuadrantids are active from Jan. 1 until the 5th, peaking tonight at 60 to 200 meteors an hour under ideal seeing conditions - dark, rural and cloudless skies. They enter the atmosphere at about 25 miles per second. European observers will have the best view of this brief peak.

The Quradantids were so-named because they appear to radiate from the obscure constellation Quadrans Muralis, in the northeast after 11 p.m. Look just below the end of the handle of the Big Dipper. (NASA sky map at left)

All the Quadrantids will appear to fly away from that point in the sky. The radiant will be highest in the sky in the hours before dawn, making that the best time to look.

Until recently, the origin of the Quadrantid meteors was unknown. They are now believed to be the remnants a disintegrated comet called 2003 EH1.

Forecasters are calling for "partly cloudy" skies tonight, with partly sunny skies Tuesday. Overnight lows will be in the mid-20s at BWI. 

Colder temperatures are back for a while, with highs this week near 40 degrees- a shade below the long-term averages. Nighttime lows will sink to the mid-20s.

We'll see a couple of cold fronts slide by - a dry one late on Tuesday, followed by another on Friday. That one could spin up a coastal storm, and forecasters at Sterling have posted a 30 percent chance for snow on Thursday night, with more cold and windy weather behind it.  

As always, if you venture out to watch, stop back here and share the experience.  

Posted by Frank Roylance at 10:26 AM | | Comments (3)
Categories: Sky Watching
        

January 2, 2011

Closest to the sun at the coldest time of year

FROM TODAY'S PRINT EDITIONS:

Winter sunOur planet is at perihelion tomorrow, the point in its elliptical orbit closest to the sun – about 3 million miles closer than at “aphelion” on July 4. Being closest to the sun at the coldest time of year seems odd. But the difference in distance has little effect on solar heating. Seasonal temperatures are driven more by the 23.4-degree tilt of Earth’s axis. Our northern hemisphere is tilted away from the sun in winter, and the lower sun angles and shorter days sharply cut solar heating. So we shiver.

(PHOTO: Getty Images, Andrew Burton) 

Posted by Frank Roylance at 12:00 AM | | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

January 1, 2011

Bright Sirius shines all night in January

FROM TODAY'S PRINT EDITIONS:

Sirius and the PupThe second decade of the third millennium begins today. Sirius, the brightest true star in the sky, crosses the meridian – its highest point in the sky - at midnight tonight. You can find Sirius (the “Dog Star”)  in the east after 9 p.m. Trace a line through the three stars of Orion’s belt, southeastward to Sirius. It’s bright because it’s close – “only” 8.8 light years from Earth. It’s orbited once in 50 years by a faint companion star, nicknamed “the Pup.” 

(X-RAY IMAGE: B. Smith, East Tennessee University, Chandra Space Telescope) 

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: From the Sun's print edition, Sky Notes
        
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This site is the Maryland Weather archive. The current Maryland Weather blog can be found here.
Frank Roylance is a reporter for The Baltimore Sun. He came to Baltimore from New Bedford, Mass. in 1980 to join the old Evening Sun. He moved to the morning Sun when the papers merged in 1992, and has spent most of his time since covering science, including astronomy and the weather. One of The Baltimore Sun's first online Web logs, the Weather Blog debuted in October 2004. In June 2006 Frank also began writing comments on local weather and stargazing for The Baltimore Sun's print Weather Page. Frank also answers readers’ weather queries for the newspaper and the blog. Frank Roylance retired in October 2011. Maryland Weather is now being updated by members of The Baltimore Sun staff
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