Well, not exactly. But I will be taking some time off to chill out, enjoy the Holidays with family and friends, do some stargazing, take naps and read stuff just for fun.  

I don't plan to post to the WeatherBlog while I'm off, but I will check in from time to time and see what if anything people are talking about. I may even forget myself and pipe up with a post or two. In the meantime, don't hesitate to send questions for the print editions' Weather Page. I'll need material for the week I get back. Don't leave me hangin' out here.

Thanks for reading the WeatherBlog in 2007. Have a terrific, and safe Holiday, and we'll see you on the other side.

Cheers,  Frank

Posted by Frank Roylance at 11:01 PM | Permalink | Comments (2)
Categories: Notes to readers
        

Go figure. Winter starts at 1:10 EST early tomorrow morning, and the weather service is predicting a Sunday high near 60 degrees for Baltimore, with a thunderstorms possible after 1 p.m. Sounds like Christmas in South Carolina. The record for a Dec. 23 in Baltimore is 69 degrees, in 1990.

Here's the deal: There's a big high pressure system over eastern Quebec at the moment. Highs spin clockwise, so that's bringing damp, cool surface air in off the Atlantic and up against the Appalachian slopes. Warmer air is moving in aloft from the west, and together they're contributing to our cool, gray, dreary weather. Showers are possible tonight, and likely tomorrow.

There's also a storm brewing in the Southwest. That's a low-pressure center, and they circulate counter-clockwise. They're expecting this one to intensify and track north and east along a fast-moving jet stream. It's likely to reach the Midwest by Sunday morning. That puts folks in the western Great Lakes in the path of some snow, but we get a strengthening flow of winds and mild, wet air from the south Sunday afternoon.

The air mass may be warm enough, and unstable enough to spark thunderstorms Sunday afternoon east of the I-95 corridor as the next cold front approaches from the west. That will clear the skies for Monday, and drop our highs back into the 40s - about right for this time of year.

Christmas in Baltimore looks at least partly sunny, with a high about 46 degrees.

The next chance for precipitation comes late Wednesday into Thursday as another "potent" storm system moves in. This one will be likely be rainy, too. No snow. Sorry.

If this weather is too depressing, click over to the new Science Matters blog and explore some of the weirdest and most interesting science news our reporters have discovered in recent days.

Posted by Frank Roylance at 10:32 AM | Permalink | Comments (0)
Categories: Forecasts
        

The latest Drought Monitor map is out today, and it indicates no change in the proportion of Maryland still experiencing moderate to severe drought.

The map shows nearly 36 percent of Maryland - the Lower Shore and Southern Maryland - is still considered in drought, despite the recent rainfall. Almost 20 percent of the state, from Dorchester County south, and in extreme southern Calvert and lower St. Mary's counties on the Western Shore, remains in "extreme" drought, based on readings of streamflow, rainfall and soil moisture. That's all unchanged from the previous week's map.

The improvement in the past week has come farther north, where the northern tier of Maryland counties enjoyed some reductions in the portion of their real estate rated as "abnormally dry." The portion rated "normal" grew from 32 percent to 40 percent of the state.

Here's some data on streamflow across the state. Here's the status of groundwater in a monitoring well in Baltimore County. 

Posted by Frank Roylance at 3:22 PM | Permalink | Comments (0)
Categories: Drought
        

If the clouds part, Marylanders will get a chance to watch tonight as the International Space Station flys over Baltimore. There will be another opportunity on Saturday evening, but the weather forecast for that one is even less promising. There's a note about it all on the Weather Page of today's Sun, but I managed to edit in an error last night that some will find confusing. Here's how it should read:

"At 6:18 p.m. today, the station will appear in the northwestern sky, fly past the bright star Vega and climb high overhead before disappearing into the Earth's shadow at 6:21 p.m.   On Saturday, the station rises in the northwest at 5:25 p.m. and flies directly over Baltimore at 5:28 p.m. before vanishing in the southeast."

My apologies for the goof.

For those who haven't tried to watch the ISS on its passages over Baltimore, you are looking for a bright, steady, star-like object that is moving briskly across the sky, at about the speed of an airliner at high altitude. If it blinks, or has multiple, colored lights, it's an airplane. Keep looking.

The station is about 240 miles above the Earth's surface, orbiting at 17,500 mph. There are three astronauts on board. One of them is flight engineer Daniel Tani, whose mother was killed yesterday when her car was struck by a freight train. She was 90. Tani was informed by Mission Control. He will not return to Earth until January at the earliest.

Posted by Frank Roylance at 8:26 AM | Permalink | Comments (0)
Categories: Sky Watching
        

You often hear people talk about how boring weather forecasting would be in Hawaii. But I would sure prefer Hawaiian weather boredom to this. With all the really cold weather bottled up in Canada, and all the snowstorms happening in the Northwest, and the Great Plains, or in northern New England, we're left with roughly average temperatures and nothing more interesting than the underside of a lot of clouds.

The official forecast suggests we're in for a weekend of rising rain chances and highs near 50 degrees. That's about 5 degrees milder than the long-term average for BWI. No bracing wintry cold. No white Christmas. But no umbrellas in our drinks on the Weatherdeck, either. Just dull and gray.

The most wintry event we're left to think about is a slight risk of slippery driving conditions north and west of the urban centers today where colder temperatures, rain and possibly some sleet may edge east from the mountains.

After some overnight clearing tonight, we may see some sunshine tomorrow. But more significant rain chances develop as the weekend approaches with a weak low out of Tennessee. With it, they say, we'll get low clouds and drizzle Friday night into Saturday. It should stay above freezing, forecasters say. But there's always a caveat: "Will have to watch surface temperatures closely for the possibility of freezing drizzle or freezing rain." Nice.

Another cold front will bring still more rain Saturday and Sunday. Okay, so we need the moisture. It's still gloomy and boring. And lots of people will be traveling.

On the bright side? If you're traveling on Monday the weather does not appear to pose a problem. Christmas Eve looks like it will be sunny during the day, with highs in the mid-40s.  Christmas Day should be mostly sunny, with a high near 43.

Posted by Frank Roylance at 12:00 PM | Permalink | Comments (0)
Categories: Forecasts
        

The planet Mars, which has been growing bigger and brighter in the northeastern sky each evening for months, tonight makes its closest approach to Earth since 2003, and the nearest until 2016.

A forecast for "mostly cloudy" skies threatens to obscure the view tonight. But Mars will continue to dominate the evening sky for several more months, even as Earth's faster orbital track begins to speed us farther and farther away.

When the clouds do part, anyone can spot Mars, gleaming high above the northeastern horizon after sunset. Its reddish hue sets it apart from the bright stars of the winter constellations in that part of the sky.

Because of peculiarities of Mars' orbit, tonight's close approach comes six days before Mars reaches "opposition,"  that is, opposite the sun as seen from Earth's perspective. That means Earth's orbit around the sun has brought it around to the same side of the solar system as Mars, which is farther from the sun, and therefore moving more slowly along its orbital track. Earth is, in effect, "lapping" Mars on its race around the sun.

So, at sunset tonight, we can look inward toward the sun at the center of the solar system as the sun sets in the west, and then turn east and look outward and watch as Mars rises.

Mars oppositions occur once every 26 months. They are prime time for planetary scientists to launch probes toward Mars, because the time and distance the craft need to traverse are shortest. NASA launched the Mars Phoenix mission toward Mars in August, and they hope to land it in the Martian polar north in May.

This 2007 opposition marks Earth's closest approach to Mars since the historic opposition in August 2003, when the planets came within just 35 million miles of each other - the nearest in all of recorded human history. Tonight's approach will bring them within 55 million miles. The next one closer than that - 47 million miles - will be in 2016.

Astronomers using the Hubble Space Telescope have been taking advantage of the shrinking distance to Mars, snapping a series of photographs of the Red Planet, and stitching them together into a video animation of a rotating Mars. The third video ("Close Encounters...") offers a nice explanation of Mars oppositions, and features Baltimore's own Streetcorner Astronomer Herman Heyn.

If you're going out to get a look at Mars anytime in the next few weeks, you can use this sky map from Sky & Telescope magazine.

Posted by Frank Roylance at 10:01 AM | Permalink | Comments (1)
Categories: Sky Watching
        

All things considered, it's easier drying out the morning newspaper than digging it out from under 8 inches of snow. I figure that's about what we would have seen this weekend had the temperatures been 10 degrees colder than they were yesterday.

As it is, I still haven't been able to read my home-delivered copy of the Sunday Sun. Plastic bag notwithstanding, it entered the house soaking wet - the Baltimore Sponge - and spent the day on the kitchen floor drying out.

We had more than 1.2 inches of rain out on the WeatherDeck in Cockeysville this weekend. Our instruments here at Calvert & Centre streets recorded 0.83 inches of rain for the storm's duration. BWI received almost an inch. Here are some more readings from around the region.

Ocean Pines:  1.95 inches

Berlin:  1.88 inches

Taneytown:  1.44 inches

Cockeysville:  1.33 inches

At BWI, we've clocked in 2.26 inches so far for the month of December, headed for what could become a normal month of precipitation - which would be only the second since April.

The weekend storm did produce some wintry weather to our west. Here's a rundown of some snow and ice accumulations.

There were some pretty impressive wind gusts, too, on Sunday. There's a rundown in the previous link; just scroll down to the wind section. Here are some highlights:

BWI:  61 mph  6:23 p.m.

Annapolis:  48 mph  5:28 p.m.

Martin Airport:  40 mph  6:39 p.m.

Westminster:  52 mph  5:31 p.m.

I was catching a nap around that time. (I had to be at BWI at 6 a.m. for a story on the USO Lounge. But I was aware enough to realize the wind was howling outside, and tugging at the roof of the house. The rafters were creaking like crazy, just itching to fly off into the next county. The lights flickered and I lost my internet connection.

I estimated later the gust was running about 45 mph. The anemometer on the WeatherDeck registered 15 mph, but it's protected by the house, and tends to run at about a third of the actual wind speed.  I could only imagine what hurricane-force winds (74 mph and up) might do.

Posted by Frank Roylance at 11:20 AM | Permalink | Comments (0)
Categories: Winter weather
        

Many observers reported being disappointed by last week's peak of the annual Geminid meteor shower. Some said clouds spoiled the view, as they did here one night. Others reported a scarcity of Geminids and wondered wether the shower is in decline.

But there was one genuinely enthusiastic report from a young family who watched the show together and were paid back handsomely for their patience and persistence. It was reported this weekend on meteorobs.org, a listserve group dedicated to year-round meteor observations. This is how meteor-observing is supposed to go: 

Posted by Frank Roylance at 12:27 PM | Permalink | Comments (1)
Categories: Sky Watching
        

The biggest slug of moisture we're going to get from this storm is past now, and dreams of a snowfall have been washed away. Here's the water vapor loop from the GOES satellite.

Looks like they recorded about 0.9 inch of rain at BWI. We had 0.70 here at The Sun, at Calvert & Centre streets downtown. That's a little over 2 inches for the month, which puts us on a track which - if it continues - should give us close to normal precipitation for December. There's plenty of water in the streams this morning. Here are some more rainfall totals from across the region.

There was a little ice in some colder locations. Here's a rundown from the NWS.

The week ahead looks sunny for the most part, with a windy start as the low passes by and we fall in behind it with a northerly flow and tight pressure gradient between the low and the following high. It will be cold Monday and Tuesday, but warm to more seasonable readings as the week advances.

In the night sky, we can look forward this week to Mars' closest approach to Earth, on the 18th (55 million miles), leading up to opposition on the 24th - when the sun, Earth and Mars stand in a straight line, with Mars rising as the sun sets. The Red Planet is a brilliant naked-eye presence high in the northeast in the evening all month. But it's the best week of the year to take a look through a telescope.

We won't be as close to Mars Tuesday as we were back in August 2003 (35 million miles), or as close as we will be in 2016 (47 million). But it will be tough to tell the difference. And, it's the nearest we'll be for the next nine years. So don't miss the opportunity to get a look. And enjoy.

Posted by Frank Roylance at 7:58 AM | Permalink | Comments (0)
Categories: Winter weather
        

So much for the big weekend storm. Forecasters have been revising their forecasts in favor of mostly rain in the I-95 corridor of Maryland this weekend. All hopes for a pre-Christmas snowstorm, and fears of a nasty ice storm, appear to have dissolved with the stubbornly mild temperatures.

Here's the official forecast. Here are the winter weather advisories, which still contain some ice worries for the mountains to our west, but little more than a touch of ice on the eastern slopes, or well to the north of Baltimore. Mostly, it just looks like a cold rain's gonna fall here. Even AccuWeather thinks so. Here's Dr. Sobel's take. In a word: Rain.

All of which speaks volumes about the hazards of forecasting "superstorms" and "Big Daddy's" for the mid-Atlantic five to seven days in advance. The science is just not good enough yet, that far out, to predict stuff like where the snow/rain line will drape across Maryland.

We'll probably continue to highlight folks like Henry Margusity and his long, long-range forecasts here because they're fun, and they get us to pay attention to potentially significant weather possibilities on the horizon. But we have to remember to take them with a bucket of salt. 

Posted by Frank Roylance at 7:36 PM | Permalink | Comments (0)
Categories: Winter weather
        

The National Weather Service has posted a winter storm watch for the entire state west of the Chesapeake Bay, signaling the potential in "some places" for at least 5 inches of snow and sleet or a quarter-inch of ice. Choose two from column A, one from column B, depending on where you live and where the storm goes. My bet is on an ice storm, with stiff winds, leading to plenty of power outages.

The watch is posted from Saturday afternoon through Sunday evening. This will be a powerful nor'easter, they say. Upstate New York will get plenty of snow, as will inland New England. But the details of what falls on the I-95 corridor in Maryland and when remain unpredictable. It all hinges on the track of a storm that is still forming over the Southwest. A little to the north and we get a lot of slop and rain. A little more to the south, and we get snow.

Either way we can use the moisture.

Here's AccuWeather's take on it. And AccuWeather's Henry Margusity. And here is Henry's snow map. Looks like ice to me.

Posted by Frank Roylance at 1:00 PM | Permalink | Comments (0)
Categories: Winter weather
        

The National Oceanic and Atmospheric Administration has issued a release noting that 2007 is on track to become another of the Top 10 warmest years on record, both in the contiguous United States and around the globe.

It notes that globally, "including 2007, seven of the eight warmest years on record have occurred since 2001 and the 10 warmest years have all occurred since 1997."  Here's more.

Posted by Frank Roylance at 10:09 AM | Permalink | Comments (2)
Categories: Climate change
        

AccuWeather, whose extreme-weather blogger Henry Margusity has been hyping this weekend's snowstorm all week, is now saying the Baltimore-Washington area should expect no more than a brief period of snow or mixed precipitation Saturday. Then it all turns to rain. The heaviest snow - 18 inches - looks like it will be confined to central NY and inland New England. 

Sorry, all you snow fanatics. Here's the latest snow map from AccuWeather.com  Looks like the Baltimore-Washington urban corridor is completely out of the accumulation zones. AccuWeather says, "The major urban areas along the Interstate 95 corridor will initially be buffeted by a mix of sleet and snow that will quickly change to a wind-whipped rain." 

The National Weather Service forecast for BWI, meanwhile, calls for rain, sleet, snow and the always popular "wintry mix."  It certainly sounds like a mess.

Garrett County in far western Maryland is already in a fix because of heavy rain from the current storm. The weather service has issued a flood warning for the county, as well as nearby portions of West Virginia and Pennsylvania:.

"AT 1138 AM EST RAIN CONTINUED TO FLOW ACROSS PRESTON...FAYETTE AND
  GARRETT COUNTIES.  REPORTED RAINFALL HAS BEEN FROM THREE QUARTERS
  TO AN INCH WITH ANOTHER QUARTER INCH EXPECTED.  SMALL STREAMS ARE
  ALREADY OUT OF BANKS AND SOME ROADS HAVE BEEN CLOSED.  THE
  ADDITIONAL RAINFALL AND CONTINUING RUNOFF WILL AGGRAVATE THE
  SITUATION THIS AFTERNOON."

You don't need snow to make a mess of things.

Posted by Frank Roylance at 2:50 PM | Permalink | Comments (3)
Categories: Winter weather
        

It looks pretty dismal out there right now. But my Clear Sky Clock alarm just went off, promising clear skies over Baltimore by 9 p.m. tonight, and a chance to see some of the 2007 Geminid meteor shower.

The Geminids constitute one of the best showers of the year. It would be THE best if it weren't typically so cold out - as many as 120 meteors per hour under dark skies. If you miss them tonight, try it again tomorrow. The peak actually falls around noon tomorrow, so either night will work.

The meteors in this shower appear to radiate from the constellation Gemini, which rises in the east in the early evening. They tend to be as bright as the Big Dipper stars, and medium-speed. The best times to look are between midnight and dawn, but if you can't stay up, give it a shot before you turn in tonight.

The unusual thing about this shower is that the dust and pebbles that create the "shooting stars" as they zip into the atmosphere, heat up, glow and vaporize, are not the debris from a passing icy, dusty comet, as is true of most meteor showers.

The Geminids are associated with a rocky asteroid, 3200 Phaethon, which just passed within about 11 million miles of Earth on Monday. That's relatively close as these things go. Some scientists think the asteroid has been pummeled by other space rocks, creating the dusty debris in its path around the sun. Others think it may not be an asteroid at all, but the husk of an expired comet, one that has lost its ice and has been reduced to a dusty nucleus.

While you're out there, don't forget to admire Mars, which is nearing opposition and its closest approach (55 million miles) and brightest appearance in the last 26 months. It's gleaming brilliantly in the northeast after sunset, the reddest, brightest star-like object in that part of the sky. We'll do more here on Mars next week.

Posted by Frank Roylance at 1:17 PM | Permalink | Comments (2)
Categories: Sky Watching
        

Maybe it was last week's snowfall. Whatever the explanation, the proportion of Maryland experiencing drought conditions has eased, according to the USDA's Drought Monitor map released this morning.

First, the region of Maryland where soil moisture, streamflow and precipitation add up to normal conditions for this time of year expanded from 11 percent to 32 percent of the state. The improvement appears to have come mainly in the northern tier, from northern Frederick, Carroll and Baltimore counties, to Harford and Cecil.

Abnormally dry conditions - or worse - now prevail in just 67 percent of the state, down from 88 percent on last week's map. Moderate to severe drought conditions prevail in almost 36 percent of the state, mainly south of the Bay Bridge on both sides of the Chesapeake. That's down from 63 percent last week.

The section still in severe drought - 20 percent of the state - includes the Lower Eastern Shore and extreme Southern Maryland. That's unchanged.

The USGS hydrological drought map is a bit different, reflecting only below-normal streamflow across the state. But the southern portions of the state are again the most severely affected.

This week's rain and snow or ice should improve things a bit more. But a great deal of precipitation is still needed throughout the region to bring groundwater and reservoirs back to where they need to be as we head into the next growing season.

Here's a full report from the USGS in Maryland.

Posted by Frank Roylance at 11:04 AM | Permalink | Comments (0)
Categories: Drought
        

A quick look this morning at two approaching storms. For both, what you see will depend on where you are. Here is the discussion from Sterling this morning. First, on today's rain/sleet event, such as it is ...  We've had no measurable precip here on the Weatherdeck in Cockeysville. It's barely wet the pavement. But, temperatures have fallen all night. It's now just 34 degrees.

For the northern tier of suburban counties, from west to east north of Baltimore's latitude:

"TEMPERATURES CONTINUE TO SLOWLY FALL TO NEAR FREEZING ACROSS THE WINTER STORM
AREA. EXPECT THAT BY THE TIME PRECIPITATION MAKES IT TO THE
REGION...TEMPERATURES WILL BE BELOW FREEZING. PRECIPITATION SHOULD
BEGIN AS A MIX OF SLEET AND FREEZING RAIN...THEN TURN TO MOSTLY
FREEZING RAIN. THE TIMING OF THE ADVISORY MAY BE TOO LONG EVEN
ACROSS THE FAR NORTHERN COUNTIES. EXPECT TEMPERATURES TO MAKE IT UP
INTO THE MID TO EVEN UPPER 30S LATE TODAY...SO FREEZING RAIN THREAT
WOULD DIMINISH TOWARDS THE END OF THE FIRST PERIOD AND LEAVE FOR
RAIN MIXING WITH SLEET. EITHER WAY...A MESSY MORNING AND PROBABLY
AFTERNOON COMMUTE."

Everybody else can expect rain.

And now, here's the chatter on the bigger weekend storm. The unknown here, as so often happens, is where the rain/snow line will form:

"PRECIPITATION WILL BE FIRST TO FORM IN OUR SOUTHWEST CWA (FORECAST AREA, INCLUDING NORTHERN VIRGINIA AND MARYLAND WEST OF THE BAY AND EAST OF GARRETT) )DURING THE MORNING...THEN WILL SPREAD NORTH AND EAST DURING THE AFTERNOON AND EVENING. GFS (COMPUTER MODEL) INDICATES THE ATMOSPHERE WOULD BE COLD ENOUGH FOR WINTRY PRECIPITATION...NAMELY SNOW/SLEET...AT THE ONSET OF PRECIPITATION
ACROSS THE ENTIRE CWA. GFS THEN TRANSITIONS TO MIXED PRECIPITATION
BACK TOWARD THE BLUE RIDGE...WITH A CHANGE TO RAIN AROUND LOWER
SOUTHERN MARYLAND. THERE IS SOME SUPPORT IN THIS TRANSITION FROM THE
SHORT RANGE (COMPUTER) ENSEMBLES...BUT ENSEMBLE GUIDANCE DOES NOT HAVE THE
RAIN/SNOW LINE TILTING QUITE AS FAR BACK AS THE 00Z GFS.

"AS IS COMMON ACROSS OUR CWA...THE RAIN/SNOW LINE WILL SET UP ACROSS
THE CWA...BUT EXACTLY WHERE IT SETS UP AND/OR HOW IT MOVES DURING
THE STORM IS YET TO BE DETERMINED. THIS WILL WILL DICTATE WHO GETS
HOW MUCH OF WHAT PRECIPITATION TYPE. REGARDLESS...QPF (MOISTURE CONTENT OF THE STORM) IS FORECAST TO
BE BOUNTIFUL WITH THIS STORM. IN ADDITION...AT LEAST A PORTION OF
OUR CWA WILL RECEIVE WINTRY PRECIPITATION. THEREFORE...THIS STORM
HAS THE POTENTIAL TO BE A HIGH IMPACT EVENT ACROSS THE CWA.

"THE MOST LIKELY SCENARIO ... IS FOR SNOW (OR SNOW/SLEET) AT THE ONSET...THEN FOR AREAS WEST OF THE BLUE RIDGE TO REMAIN MOSTLY SNOW FOR THE DURATION WHILE
OTHER PLACES EXPERIENCE A MESSY WINTRY MIX THAT WOULD INCLUDE
FREEZING RAIN. THE BEST CHANCE OF A TOTAL CHANGEOVER TO RAIN WOULD
OCCUR ACROSS LOWER SOUTHERN MARYLAND AND THE MID BAY. AS THE STORM
RE-DEVELOPS OF THE MID ATLANTIC COAST...MIXED PRECIPITATION WOULD
LIKELY TRANSITION BACK TO SNOW TOWARD THE END OF THE EVENT SUNDAY
MORNING."

Over at AccuWeather, Dr. Joe Sobel seems more sober about the prospects here for the weekend storm than we have been seeing this week from Henry Margusity. Looks like more rain and icy slop than snow as the storm takes a more northerly track. Here's where they see the storm's greatest impact. We're on the fringe.

Posted by Frank Roylance at 8:21 AM | Permalink | Comments (0)
Categories: Winter weather
        

We may have some ice to contend with in the morning. The National Weather Service has posted a winter weather advisory, in effect from 3 a.m. to 6 p.m. Thursday for Central and Western Maryland as far south as Howard County, Baltimore and eastward to the Bay.

Here's the heart of it:

"FREEZING RAIN AND SLEET WILL OVERSPREAD THE REGION PRIOR TO SUNRISE.
A MIX OF PRECIPITATION WILL CONTINUE THROUGH DAY...SLOWLY CHANGING
TO RAIN FROM SOUTH TO NORTH. COLD AIR...AND THUS FREEZING
PRECIPITATION...WILL HOLD ON THE LONGEST IN THE VALLEYS AND ALONG
THE MASON DIXON LINE. A FEW LOCATIONS MAY REMAIN ICY THROUGH THE
DAY.

"ONE TO TWO TENTHS OF AN INCH OF SLEET AND FREEZING RAIN WILL BE
POSSIBLE BY SUNSET THURSDAY.

"A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR
FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR
SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING."

And here's the forecast for Baltimore proper. Ick.

This, of course, is NOT the big storm forecast for Saturday and Sunday, just a little one tracking along the stalled front that's been parked over us since Sunday, providing alternately mild and cool temperatures and plenty of drizzle and fog. 

The BIG storm is beginning to sound wetter and icier for us, with the all-snow event pushed farther to our west and north and northeast. Here's a bit of this afternoon's discussion from Sterling:

"A WIDE AREAL RANGE OF MIXED WINTRY PRECIP EXPECTED ACROSS THE I-95
CORRIDOR W/ THIS WEEKEND EVENT. A COLD RAIN ON SAT. AFTERNOON POSSIBLY
TURNING INTO FREEZING RAIN/SLEET MIX INTO THE EVENING AND OVERNIGHT HRS. SNOW
MOST LIKELY ACROSS THE I-81 CORRIDOR...MIXING INTO THE PRECIP BACK
TO THE EAST OVERNIGHT SAT/SUN MORNING. (MOISTURE) LOOKS TO BE DECENT FOR
THE INCOMING SYSTEM...W/ BOTH AN ATLANTIC AND GULF OF MEXICO
MOISTURE ENHANCEMENT... AMOUNTS OF WINTRY PRECIP STILL
UNCERTAIN W/ MANY INTERWORKING VARIABLES ... "

Madman Margusity, of course, sees a more southerly track, and more snow - maybe even thundersnow - in the densely populated I-95 corridor. 

Posted by Frank Roylance at 4:20 PM | Permalink | Comments (0)
Categories: Winter weather
        

As drippy as it's been, it's easy to forget we're still in a drought. That's why yesterday's announcement from Baltimore water authorities - that they will be tapping the Susquehanna River next week to augment water supplies from the city's three reservoirs - came as a surprise to some.

How dry are we? Here are some facts from the U.S. Geological Survey:

RAINFALL: Although Baltimore (BWI) is about 7.5 inches behind the long-term average rainfall for this year, the deficit is more critical on the Eastern Shore. Since January, Worcester County has fallen 13 inches short of the average precipitation. Somerset and Wicomico are 11 inches in the red. So are Howard and Montgomery counties on the other side of the Bay.

STREAMFLOW: Three Maryland streams broke all-time low-flow records for November. The Patuxent, measured at Unity, busted a 63-year-old record, with a flow rate of 8.24 cubic feet per second. The average since 1944 is 22.8 cf/s. Nassawango Creek on the Eastern Shore broke a record that had stood since 1949. And St. Clement's Creek, in St. Mary's County, broke a 39-year-old record.

GROUNDWATER: Wells monitored by the USGS in Carroll and Harford counties reached record low levels for November. Groundwater levels were below normal in 17 of the 25 shallow, unconfined wells the agency watches. Another eight wells were at very low levels, including one in Baltimore County. The lowest levels were noted on Delmarva.

RESERVOIRS: Although the water in Baltimore's three reservoirs is now falling below 66 percent of capacity - triggering the decision to tap the Susquehanna - the level in Prettyboy has dropped to 53 percent. Prettyboy is used to feed the Gunpowder River, which flows to Loch Raven Reservoir and keeps it high enough to feed water to the Montebello filtration plant. Loch Raven was at 81 percent of capacity at the end of November. Liberty Reservoir, which feeds the Ashburton filtration plant, stood at 73 percent of capacity.

The Patuxent Reservoirs which serve Montgomery and Prince George's counties, are lower, at a combined 52 percent of capacity. Tridelphia stood at 60 percent at month's end. The Duckett reservoir was at 39 percent.

Posted by Frank Roylance at 3:54 PM | Permalink | Comments (0)
Categories: Drought
        

Sure, we're short of rain around here, and the creeks and wells are low, and they're already tapping the Susquehanna River to ease the pressure on Baltimore's reservoirs. But this isn't Atlanta. I received this email this morning from former Marylander Janice Nuckols:

"You should come here to Atlanta!  County I live in has had mandatory water restrictions for 2 years.  I’m seriously considering planting cactus next year.  I’ve called the “water police” on people who wash their cars or use water outdoors.  Can’t water outdoors, nurseries are going bankrupt and landscapers are out of jobs.  Car washes can only operate if they recycle the water. 

"We’re 20” down for the year.  They say next year isn’t any better.  Our governor and Alabama and Florida fight over water all the time.

"A few weeks ago I saw people buying 5 gallon bottles of water to stock pile in the grocery store.

"A couple of months ago, Stone Mountain was making snow with millions of gallons of water for a winter attraction on a day that was 80 degrees.  The outrage from people was unreal.  Stone Mountain stopped making the snow. 

Posted by Frank Roylance at 1:22 PM | Permalink | Comments (3)
Categories: Drought
        

Temperatures in Baltimore have been rising steadily since sunset yesterday, nearing 60 degrees late this morning. You'd never guess we're expecting a big snowstorm this weekend.

But that seems to be increasingly likely. AccuWeather's extreme-weather blogger Henry Margusity is still hyping the storm, of course. But now, as the forecast range grows shorter, even the National Weather Service is becoming more confident.

The official forecast for the weekend still calls for "a chance of rain or snow" beginning Saturday afternoon, followed by "snow or rain likely" Saturday night, and "a chance of snow or rain" again Sunday.

But in their morning discussion, forecasters are sounding more convinced. There's still a lot of uncertainty about where the rain/snow line will fall, of course. But they acknowledge that the weekend storm "could be a high-impact event across the (forecast area)."

More on the storm in a minute. First, we need to pick our way through a lot of weather that's expected here between now and then.

First, as you no doubt noticed heading out this morning, there is a warm front pressing into the region from the south today. It's actually the same stalled front that's been giving us cool weather and periodic showers and fog all week. Only now it's on the march northward. 

After temperatures flirt with the low 60s today, the front will move south again this evening as a cold front, dropping a few showers here and there and sinking temperatures tonight into the 30s. A storm system tracking along the front tomorrow will bring us some more precipitation. It could begin Thursday morning as freezing rain or sleet in western and northern counties, but mostly we should see rain. Welcome rain, I should add, a quarter- to a half-inch. They'll see ice and snow to our north.

Winter storm watches are already posted for tomorrow just north of the Mason-Dixon Line.

Whatever falls here, it should all be rain by late Thursday as the front moves north again as a warm front. And they're expecting it to end Thursday evening. Then high pressure and colder temperatures move in. Friday should actually be sunny. Remember sunny? But it's the sunny before the storm.

Forecasters say the real winter storm will approach us on Saturday. Morning lows will be in the upper 20s, rising to only 37 on Saturday at BWI. This morning's discussion says, "Confidence is reasonably high that such a storm will develop and affect the (forecast area) over the weekend. Yet there remain uncertainties about the details ...namely track, strength and timing."

And therein lies the rub. The storm center is expected to reach the central Appalachians, weaken there and spawn a secondary low off the Virginia coast. That would intensify the system, and gin up more snow and wind. And the storm track is critical to where there snow/rain line falls.

For now everybody - the NWS, AccuWeather and Madman Margusity - seems to be sketching that line in along the I-95 corridor. But a twitch either way could mean the difference between a few inches of slush and 6 or 10 inches of snow. Here's Capital Weather's take.

"Needless to say," the folks at Sterling said anyway, "specifics such as the rain/snow line will need to be resolved as we get closer to this potentially high impact storm."

For what it's worth, here's Henry's latest snow map:

Posted by Frank Roylance at 10:23 AM | Permalink | Comments (1)
Categories: Forecasts
        

Five days before the first flake falls, AccuWeather's Henry "Madman" Margusity has already loosed the words "blizzard" and "Superstorm" in connection with this weekend's storm. The extreme-weather blogger has even posted a snowmap that gives Baltimore 3 to 6 inches by Monday morning, while western counties sink beneath 6 to 12. He knows it's way too early to be that smart. But he posted it anyway.

And that's just the kinda guy he is. Nobody else has scootched that far out on the limb yet. But Hank says he couldn't resist.

The National Weather Service is still hedging its bets. The computer models still don't agree, and there are just too many variables to say where the storm will go, and who will get what sort of precipitation. The discussion today suggests a more southerly track would bring us snow, but other models have the storm on a more northerly trajectory, leaving us with rain and mixed precipitation. The official forecast says only "snow likely" on Saturday night, then "chance of snow or rain" on Sunday.

The one thing that does seem to be coming into focus is the fact that a significant "nor'easter" could be brewing. And nor'easters are the kind of storm that has brought Baltimore its deepest and most disruptive winter snow events. There is also talk of this storm scooping up moisture from sub-tropical storm Olga, now pummeling Hispaniola.

Anyway, Henry's map will surely have to be revised as the days slip by, but here it is anyway, just for fun. The "Cat.3" and "Cat.4" stuff, BTW, refers to the Northeast Snowfall Impact Scale. Here's more on that.

Posted by Frank Roylance at 2:36 PM | Permalink | Comments (59)
Categories: Winter weather
        

Looks like we're in for a snowstorm this weekend. Or maybe not. The various computer models don't agree on how the forces of Nature will play out over the next five days. Here's a sampler:

From this morning's discussion at the National Weather Service's Sterling forecast center (I've edited it for jargon):

"GUIDANCE NOW IN VERY GOOD AGREEMENT IN DEVELOPING A POTENTIALLY SIGNIFICANT
WINTER STORM DURING THE SECOND HALF OF THE WEEKEND IN RESPONSE TO
DEEPENING TROUGH OVER THE MIDDLE OF THE COUNTRY FRIDAY. HOWEVER...GUIDANCE
REMAINS SOMEWHAT SPLIT WITH GEFS/NCEP (COMPUTER MODELS) ... INDICATING A MORE OF A
SOUTHERN TRACK (SNOW)FROM THE SOUTHEAST COAST TO CAPE HATTERAS AND OUT TO
SEA WHILE ECMWF (MODEL) IS MORE ROBUST AND MUCH SLOWER INDICATING A ... TRACK FURTHER INLAND SUGGESTING THE POSSIBILITY OF MORE OF A MIXED PRECIP/RAIN EVENT.

Posted by Frank Roylance at 9:29 AM | Permalink | Comments (0)
Categories: Winter weather
        

And you thought the hurricane season was over ... The National Hurricane Center is issuing advisories for a new "sub-tropical storm" which has earned the name Olga - the 15th named storm of the 2007 Atlantic season.

The storm is headed for Puerto Rico with winds up to 40 mph and 2 to 4 inches of rain - maybe 6 inches in some locations. That could mean flash flooding and landslides on the U.S. island and farther west on Hispaniola.

Here is the latest advisory. Here is the storm's projected track. And here is the satellite view.

So what's a "subtropical" storm? Here's the hurricane center's definition:

"A non-frontal low pressure system that has characteristics of both tropical and extratropical cyclones.

"The most common type is an upper-level cold low with circulation extending to the surface layer and maximum sustained winds generally occurring at a radius of about 100 miles or more from the center. In comparison to tropical cyclones, such systems have a relatively broad zone of maximum winds that is located farther from the center, and typically have a less symmetric wind field and distribution of convection.

"A second type of subtropical cyclone is a mesoscale low originating in or near a frontolyzing zone of horizontal wind shear, with radius of maximum sustained winds generally less than 30 miles. The entire circulation may initially have a diameter of less than 100 miles. These generally short-lived systems may be either cold core or warm core."

Got that? This will be on the quiz.

Posted by Frank Roylance at 9:11 AM | Permalink | Comments (1)
Categories: Hurricanes
        

The 2007 Atlantic hurricane season ended 10 days ago, but that hasn't stopped the development of a tropical disturbance in the Atlantic Ocean that threatens the U.S. Virgin Islands and Puerto Rico with damaging rains and mudslides.

Here's the statement from the National Hurricane Center. Here's the satellite view.

Posted by Frank Roylance at 1:42 PM | Permalink | Comments (0)
Categories: Hurricanes
        

Couldn't rake the leaves yesterday. Too cold. Too wet. And I booted the chance to get them up during the surprisingly nice weather on Saturday. Now it doesn't look like they'll get raked until this weekend. Gray and wet and miserable nearly all week. So light a fire. Fight the gloom.

And look on the bright side. All this drippy weather is providing a bit of moisture for the soil. It's soaking in nice and slowly. Also a good thing. It hasn't amounted to a whole lot. But we're about a third of the way throught the month, and we've had about a third of the normal cumulative rainfall we expect in December. It's not exactly a gusher, and the water tables still need a lot more. But at least we're not losing ground for now.

Forecasters say we're stuck alongside a stalled cold front. We're on the colder north side for now, and it's warmer to our south. But that boundary will be moving around some. Warmer, wetter air riding up over the denser, colder air at the surface in our region produced this morning's fog.

Scooting along the front are a series of weak low-pressure systems. Every now and then they'll slide out of the Southwest and slip through here with some showers and plenty of gray skies. Here's the radar loop.

This pattern will likely persist through Thursday, forecasters say. High temperatures will remain in the low 50s, which is unseasonably mild. This morning's discussion down in Sterling says they "wouldn't be shocked to see mid-60s" Tuesday.

The overnight lows won't get much below 40 degrees until a stronger cold front arrives on Friday to shove all this stuff out of the area. The weekend looks mostly cloudy but noticeably colder. Make time for rake time.

Posted by Frank Roylance at 10:41 AM | Permalink | Comments (1)
Categories: Forecasts
        

Here's a way-cool photo, shot yesterday by one of NASA's Earth Observing satellites, of the northeastern United States in the wake of the Dec. 5 snowstorm that swept across Maryland's northern counties. It was a sunny day, so the white you're seeing on the ground is snow cover. The white streaks out over the ocean are clouds.

I'm guessing the white on Lake Ontario is clouds, too - lake-effect snow in the air? Too early in the season for ice there.

My only complaint about these images is that NASA always feels compelled to superimpose the states' boundaries. I'd rather see it the way visiting aliens see the place. Here's more.

Posted by Frank Roylance at 2:22 PM | Permalink | Comments (0)
Categories: Cool pictures
        

You know, I'd much rather have a real snowy day, or a really cold and sunny day, than this. Just listen to today's forecast from the National Weather Service:

"Rain, snow and sleet likely before noon, then snow likely possibly mixed with sleet between noon and 1 p.m., then a chance of rain, snow and sleet between 1 pm and 2 pm, then a chance of rain and sleet after 2 p.m."

Here's the winter weather advisory.

I mean, really. They're calling it "a light wintry mix." Sounds like some kind of salad. But this is just nasty. The scrapings of real weather. It's not even going to accumulate and make this job interesting. We're stuck here on the sloppy edge of a real snowstorm to our north.

And the rest of the weekend and the beginning of next week aren't a lot more promising. Chance of rain. Mostly cloudy. A chance of showers. Cloudy. A chance of showers (again and again.). Here, read it for yourself.

Hey! Out there in Sterling! You can do better than this!

Okay, maybe if the "chances" for showers were a little better, and we could count on some needed precipitation, we could sigh and put up with it. But we're looking at 30 percent chances here, at least once we get past today. That's just drippy weather. No help at all.

It's not even going to FEEL like winter at the start of next week. They're forecasting a high of 60 degrees on Tuesday, for Pete's sake. It's supposed to be 40-something.

The problem seems to be a weak storm system that's drifting through today along a stalled cold front. After that it's dueling cold and warm fronts - cold late Monday, warm on Tuesday, then cold again on Wednesday.

I give up.

Posted by Frank Roylance at 10:40 AM | Permalink | Comments (4)
Categories: Forecasts
        

Well now, that wasn't so bad was it? A nice, small, manageable late-autumn snowstorm. Except for the traffic, that is. Which was horrible. And the early dismissals, which are always a headache. And all that scraping this morning. Okay, maybe it was a pain. In a way.

But hey. It was beautiful, right? Snow lacing the trees and decorating all the rooftops and making the place look like an actual Christmas scene, which it hardly ever does before Christmas around here. We LIKE this! Snow - at least at this end of the winter season, if it doesn't pile up to a foot or two and paralyze the place - is a GOOD thing. We can use the moisture, however it's delivered. It will melt nice and slowly and soak into the soil, where it's badly needed.

Here are the numbers. The official total for Baltimore, as measured at BWI, was 4.7 inches. We had 4.5 inches out on the WeatherDeck in Cockeysville. But they measured 7.3 inches out near Deep Run in Carroll County - maybe the deepest anywhere for this storm. There were 6.4 inches in Glen Burnie; 5 inches in Jacksonville; 1.3 inches in La Plata; 4.5 inches in the city; 5.5 inches in Fallston and 5.4 inches in Columbia.

Here are some other tallies from around the region. And here are more.

The total at BWI from yesterday's storm was more than we've seen in 15 of the last 20 Decembers in Baltimore.  But four of the last six Decembers have produced 4 inches or more. The long-term average for a December at BWI is just 1.7 inches.

Posted by Frank Roylance at 10:22 AM | Permalink | Comments (0)
Categories: Winter weather
        

The season's first measurable snowfall dropped 1 to 4 inches across the region after taking a southerly track that put us in what one meteorologist called the Alberta Clipper's "sweet spot."

Todd Miner, at Penn State Weather Communications, said these Clipper systems don't pack much moisture. The heaviest amounts - maybe 2 to 5 inches - tend to fall within a narrow corridor 40 to 80 miles wide just north of the track of the central low.

This one, which had initially been expected to track further north, instead swept by us to the south of the Baltimore-Washington area. That put us smack in the sweet spot all day long. The southerly track also kept us in the cold sector of the storm, holding temperatures below freezing all day.

The cold and frozen p[recipitation made driving far from sweet, and more hazardous than many commuters expected. There were hundreds of accidents that snarled traffic during both commutes.

Here are some accumulation reports from the National Weather Service. And here's AccuWeather's snow totals map through the late afternoon. 

Posted by Frank Roylance at 5:53 PM | Permalink | Comments (2)
Categories: Winter weather
        

Maybe you noticed the snow outside. Forecasters say this "Alberta Clipper" tracked farther south than expected, putting us in line for colder air and a little more snow than they anticipated.

Instead of maybe an inch and a half by the time it ends - and highs today around 36 degrees - which is what they were saying last night, the National Weather Service is now saying we can expect a high around freezing, with up to 3 inches possible across the region. A few areas caught by locally more intense snowfall could see up to 4 inches. Snow advisories - confined yesterday to the western counties - have been extended across Central Maryland and the Upper Eastern Shore. Here are the advisories for our area. A snow advisory means you can expect snowy roads and low visibility.

Here are some Traffic Cam views from WMAR TV. 

1 PM UPDATE: My wife just called from Upperco, in northern Baltimore County, to report two inches on the ground there. Here are some more readings.

Here's the radar loop. And here's the wider picture from AccuWeather. And here's AccuWeather's Madman Margusity's take - also 1 to 3.

It ain't much, folks, but it then it doesn't take much to slow Marylanders down.

Baltimore, Harford, Carroll, Charles, Washington and Frederick county schools have already decided to close early. They'll probably be sending the kids out into the worst of the storm. Go figure. Allegany and Garrett schools never opened.

Reports from weary commuters indicate the ride to work - on roads merely wetted by the snow - was long and slow. Sun tech reporter Chris Emery said it took him two hours to make the 40-minute commute from Silver Spring. He tried 95 - a "parking lot." Then he switched to the BW Parkway - a "parking lot." 

I didn't have any problems. The JFX slowed a little, but it was just wet, with airborne snow swirling across the pavement. But then I come down after the worst of the rush hour. How was it out there for everybody else? Readers? 

Anyway, the forecasters out at Sterling are now saying we should expect the snow to continue throughout the day. It may intensify for a time in the afternoon, then begin to taper off during the evening. Skies should clear overnight and give us a sunny day tomorrow. You can track accumulations here.

Too bad the clearing will come too late to give us a view of the International Space Station, which will make a fine pass right over Baltimore at 5:39 this evening.

Posted by Frank Roylance at 10:39 AM | Permalink | Comments (3)
Categories: Winter weather
        

Well, it still doesn't look like much to worry about. But the National Weather Service has boosted its estimate of the likelihood we'll see some accumulating snow tomorrow.

The official forecast now calls for a "slight" chance for snow starting after midnight tonight - 20 percent. But the odds improve to "likely" - 60 percent - for Wednesday. "New snow accumulation of 1 to 2 inches possible," they say. And they're looking for snow chances to continue into the evening, rated at 30 percent. Here's the NWS forecast map for accumulations through 7 p.m. Wednesday.

AccuWeather's snow monger Henry Margusity isn't too exercised about this one. He says, "The problem spot will be east of the Appalachians across PA, Maryland and Virginia where some snow will sneak over the mountains, but -- will it mix with a little rain and just how much can fall? Right now, it looks like just a lot of dustings to perhaps an inch ..."

This morning's NWS discussion out at Sterling isn't very helpful. They're talking about "a more significant Clipper system than what was originally thought."  But the computer models seem to suggest at least an inch of snow or more in the mountains over 12 hours, and less as you look farther east. None of the computers forecast more than 4 inches.

That said, having any kind of a snowstorm on Dec. 5 would please those among us who have noted the frequency with which we seem to get snow here on that date. Here's how the last five Dec. 5's have performed:

2006:  Trace

2005:  1.4 inches

2004:  None

2003:  3.0 inches

2002:  7.4 inches

So, in four of the last five years, we've seen snow at BWI on Dec. 5. Snow tomorrow would make it five out of six. On the other hand, none of the previous five years saw snow on that date.

The winter weather dates I watch are the period from Feb. 11 to Feb. 19. Five of the biggest snowstorms on record for Baltimore (and six of the top ten for Washington DC) have occurred within that period. That's "Snow Week on the Chesapeake."

Posted by Frank Roylance at 10:47 AM | Permalink | Comments (2)
Categories: Winter weather
        

Sure there are flake icons on the NWS forecast page for Baltimore. But I wouldn't let it worry you much. They're billing it as a "slight" chance for snow Wednesday evening through Thursday as a little "clipper" system moves our way out of central Canada. They put the chances at only 20 to 30 percent. Our really big snows come from coastal storms that sweep up from the south or southwest. 

Also, the cold, dry, high-pressure system that's rushing into the region with these high winds should leave us too dry for this weak system to generate much snow. Call it a dusting at best. (If we wake to 6 inches, I've never heard of this blog.)

Speaking of high winds, we clocked the peak gust at 28 mph here at Calvert & Centre streets around 10 a.m. The barometer bottomed out at 29.61 inches at 6 a.m., and has been climbing ever since as the low that brought us rain over the weekend (and snow to our north) heads off to the northeast and the high pressure system builds in.

Winds around the region have ranged from 10 mph to 30 mph, with gusts as high as 46 mph (at Martinsburg, W.V.). BWI reported sustained winds at 30 mph with gusts to 39 mph in the last hour. You can track the winds here. Just scroll down to the "Current Hourly Weather Observations" and look in the "Winds" column. Here's another rundown from the NWS.

And BTW, take a second a check out The Sun's new science blog, "Science Matters." It debuts today, with contributions by Sun reporters Chris Emery, Dennis O'Brien and yours truly. We hope to keep it lively and interesting and unpredictable. Let us know what you think.

Posted by Frank Roylance at 11:40 AM | Permalink | Comments (2)
Categories: Winter weather
        

All sorts of advisories and other alerts in the forecast this afternoon. The rain is likely to pick up tonight as the cold front pushes through. And behind the front we'll have a new, colder air mass rushing in throughout the day Monday behind the departing storm.

They're warning of wind gusts in excess of 46 mph around here. They could top 60 mph in the mountains. Expect wind restrictions on the bridges. You'll have to find a new route for the old Winnebago.

And to top it all off, the forecast for the week ahead shows a 30 percent chance of some light snow late Wednesday into Thursday. Here's a snippet from the discussion out at Sterling. (My jargon translations in parentheses):

"NEXT CLIPPER TYPE SYSTEM WILL SPREAD SNOW ACROSS THE AREA AS EARLY
AS (1 a.m.) WED. THIS COULD BE A PROBLEM FOR MORNING RUSH HOUR. ... (COMPUTER MODELS) HAVE BEEN CONSISTENT WITH SYSTEM ALTHOUGH AMOUNT OF (PRECIP. AND TIMING) A BIG QUESTION. TEMPERATURES HOWEVER SHOULD BE COLD ENOUGH FOR A MAINLY
ALL SNOW EVENT. QUITE POSSIBLE TO GET A DUSTING TO AN INCH OF SNOW
EAST OF THE MTNS"

Notice the high temperatures forecast for BWI on Wednesday and Thursday - only in the 30s. That's more than 10 degrees below the longterm average for this time of year.

In the meantime, the storm has dropped some snow well to our north. here's how it looks at Cornell University, in Ithaca, NY.

Posted by Frank Roylance at 3:47 PM | Permalink | Comments (0)
Categories: Forecasts