It was a pretty frosty morning. Temperatures dropped to 24 here at Calvert & Centre streets, and into the teens out on the WeatherDeck in Cockeysville. The official low was 18 degrees at BWI. But there's spring in the forecast.

Once we get past some rain late today and tomorrow, the sun will return on Sunday. And when that high-pressure system slides off the coast, we will fall under a more southerly flow around the back side of its clockwise circulation. That will push temperatures to a seasonable 50 degrees on Sunday and near 60 on Monday, under sunny skies.

The average high for Baltimore at this time of year is 49 degrees.

That should bring a lot of us out of hibernation. My wife is already after me to rake the rest of the oak leaves out of the front flower beds, to give the bulb shoots some breathing room. Plenty of litter to pick up, too, after high winds in the last few days got into the trash at the curb. They should outlaw styrofoam peanuts.

So, are we done with snow for the season?

The weather statistics are not entirely reassuring.

Snowfall has topped 10 inches in March in six years since they started keeping track of snow in Baltimore in 1883. The historic, record storm for March, of course, was the infamous Palm Sunday Snowstorm, on Mar. 29-30, 1942. That one surprised the region with more than 20 inches of wet snow on bulbs and blossoms. Baltimore measured 22 inches. Anyone out there remember it?

Here's how the National Weather Service describes it:

"The storm began as rain but changed over to a wet heavy snow. The snow stuck to power lines, trees and shrubs damaging them under its weight. Many of the fruit trees had begun to blossom.

"Over 20 inches fell over northern Anne Arundel, Howard, Southern and western Baltimore County, Carroll County, eastern and northern Frederick County, and north-central Washington County. Maximum amounts reported were 31 inches at Clear Springs (just 12 days earlier the temperature had reached 79�F here), 32 inches at Westminister, 30 to 36 inches at State Sanatorium (Frederick County) and 36 inches at Edgemont (Washington County).

"Baltimore City received its greatest snow in 20 years with 22 inches measured. Hagerstown and Westminister reported 22 inches in 24 hours. Frederick had 17 inches in 24 hours. Washington, DC received a total of 11.5 inches of snow."

We also still run the risk of strong spring nor'easters - even without snow. Old-timers may recall the "Storm of the Century" on Mar. 6-7, 1962 that tore into the beach resorts on the Maryland and Delaware shores. And that was just a piece of the coastal devastation that occurred from the Carolinas to New England.

That storm struck during a new moon, and unusually high, storm-driven tides swept waves across the barrier islands to the bays. Water and waves, and floating debris demolished the boardwalks and many homes and hotels along the beach. Winds gusted to hurricane force. High water and waves flooded everything in 2 to 5 feet of salt water. And each high tide brought more damage. Cars were buried in shifting sands. Firefighters, the Coast Guard and National Guardsmen worked to rescue stranded residents.

Police and armed Guardsmen with fixed bayonets also stood watch over splintered homes and businesses to prevent looting.

Could this happen again? Does anyone out there remember this storm? Drop a comment here and share your recollections.

Posted by Frank Roylance at 11:15 AM | Permalink | Comments (3)
Categories: Forecasts
        

                                                                                 Image supplied by FreeFoto.com 

As the calendar flips over to March this weekend, take a minute to contemplate this: This Easter, on the 23rd, will be the earliest Easter in the entire lifetimes of everyone living on the planet today.

In fact, it's the earliest for any year in the 250 years between 1875 and 2124. It is matched only by Easter in 1913 - 95 years ago. So, for a few of our oldest neighbors (my mom among them), this will actually be the second time they've enjoyed an Easter this early.

Under the ecclesiastical rules set centuries ago by the Roman Catholic Church, Easter can fall anywhere between Mar. 22 and April 25, according to calculations by M.J. Montes.  But some dates crop up on the list more frequently than others.

For example, in all of those 250 years, Easter never occurs on Mar. 22 - the earliest date possible. It occurs only once on Mar. 24. That was in 1940 - the rarest Easter date of them all in that quarter-millennium. Easter falls on Mar. 23 only twice (in 1913 and 2008) and just twice on April 24 (in 2011 and 2095). All the rest are more common than this year's Easter date.

The most common dates for Easter between 1875 and 2124? Those would be April 10 and April 17 - with 11 Easters each on those dates.

So what are the rules for setting the dates for Easter?

The shorthand answer has always been that Easter falls on the first Sunday after the first full moon after the Vernal Equinox. This year, the Equinox occurs on Mar. 20, the moon is full on the 21st, and so Easter lands on the 23rd.

The actual rules are a bit more arcane. The quirk is that Church fathers did not adopt the astronomical definition for the Vernal Equinox, which can shift across several dates centered on Mar. 21. Instead, the Church fixed its ecclesiastical equinox on Mar. 21.

They also established "lunation" tables to determine when the full moons occur - tables that track the astronomical full moon, sort of, but not always, according to the U.S. Naval Observatory.

As a result, the ecclesiastical equinox can differ from the astronomical, and the ecclesiastical full moon can stray from the astronomical definition. To make it even more confusing, various branches of Christianity, in particular the Eastern churches that still use the old Julian Calendar, follow their own rules, producing different dates.

The rest of us just check the calendar. Happy Leap Day.

UPDATE: An earlier version of this post mistakenly listed April 25 as another date on which Easter does not occur between 1875 and 2124. In fact, it occurs three times in that period: 1886, 1943 and 2038. The WeatherBlog regrets the error.

Posted by Frank Roylance at 10:39 AM | Permalink | Comments (4)
Categories: By the numbers
        

The forecast isn't perfect, but we've got a good shot at clear skies for two fine passes by the International Space Station in the next few days. All you need is a willingness to roll out of bed earlier than anyone should have to on a weekend, or a Monday morning.

UPDATE at 5:15 p.m. Friday: Actually, the Saturday morning forecast has deteriorated. They're calling for snow or rain before noon. Too bad. Monday still looks good. Earlier post follows.

The ISS is brighter than ever these days, thanks to the shiny new Columbus module transported to the station this month by astronauts aboard the space shuttle Atlantis, and new solar panels and radiators added in other recent flights. Here's a cool video, shot by amateurs from the ground, of Atlantis approaching the station.

And here, speeded up by time-lapse video, is how it looks to the naked eye.

Even at ranges of several hundred miles, the station can be nearly the brightest object in the night sky, except for the moon. It's not hard to see even in the fading light of dusk, or the brightening skies before dawn. And it's always a kick to watch it soar over Baltimore, with three crew members on board, at about 17,500 mph. So much money spent; so few people paying any attention. 

The ISS is visible early every morning for the next week, but most of the flyovers appear low on our horizons, making them difficult, or inconvenient to watch. But two will be especially bright, and high over Maryland skies.

Here are the specifics:

The first will occur on Saturday morning as the ISS cruises from the northern Gulf Coast, almost directly over Baltimore, then on up the East Coast to Boston and Nova Scotia.

Look for the station to appear over the southwest horizon at about 6:10 a.m. Watch for a steady, bright, star-like object climbing high into the sky, reaching a point almost directly overhead at 6:12 a.m. (If it blinks, has multiple or colored lights, it's an airplane. Keep looking.)

It will have an apparent magnitude, or bightness, of minus-2.4 - about that of the planet Jupiter. From its zenith, the ISS will slip off toward the northeast, disappearing at 6:15 a.m.

The next best pass will come early Monday morning, with the station on a trajectory almost identical to Saturday's, except nearly an hour earlier. (I know, it's tough on a Monday morning, too. )

Watch for the ISS to appear abruptly, already well above the southwestern horizon at 5:19 a.m. as it leaves the Earth's shadow and enters direct sunlight. It will quickly reach its highest point, about 74 degrees above the southeastern horizon, at 5:20 a.m. From there it will glide off toward the northeast, disappearing at 5:23 a.m.

Remember to stop back here after the show, leave a comment, and share the experience with the sleepyheads who passed it up.

Although the ISS looks like a bright dot to the naked eye, and even in binoculars, many amateur astronomers and satellite buffs using tracking software and telescopes have grabbed some impressive images of the station during passes like these. They give you a sense of what you're seeing. Here's an especially striking example.

Posted by Frank Roylance at 10:16 AM | Permalink | Comments (0)
Categories: Sky Watching
        

I was just sitting here knocking out some Weather Page comments for later in the week, noting how little snow we've had this winter here in Baltimore - just a shade over 8 inches. Of that, more than 7 inches fell in just two storms. How different it's been out on Maryland's western frontier.

Dave Buck, at the State Highway Administration reminded me last Friday, as I was putting together our Saturday ice-storm story, that parts of the mountain counties have seen 25 accumulating snowstorms this winter. Keyser's Ridge, in Garrett County has had a total of 75 inches, Buck said.

Deep Creek Lake image from Railey Realty webcam 

Or at least that's what they'd had by Friday. There's more snow ahead for those folks this week. A Heavy Snow Warning is posted for Garrett. Cold air pouring into the region from the northwest is bringing more snow out there today. Some locations in Garrett and Allegany will see 5 to 8 inches today and tonight, with up to 10 inches possible in some spots.

There are scattered snow showers in the forecast for us flatlanders, but with temperatures already in the 40s, that seems like wishful thinking. But colder air is piling in. BWI will sink to 20 degrees tonight, and with stiff northwest winds, the wind chills will drop to the teens, despite the return of some sunshine.

There could be still more light snow for the mountains on Friday as another little storm trips down from the Great Lakes. We get rain. Saturday bumps up the risk of snow showers again, but Sunday and Monday look like a breath of spring. Highs will run up into the 50s, to near 60 degrees by Monday.

The next storm could bring us heavy rains by Tuesday.  We'll take them. 

Posted by Frank Roylance at 11:37 AM | Permalink | Comments (1)
Categories: Winter weather
        

The satellite image shows us socked in under rain clouds today. This rain is a good thing. Sure, it's gray and gloomy. And dank. And lots of us would rather have a good 10-inch snowstorm to remind us that this is winter in Maryland.

But while some would welcome snow, it comes at a cost in salt and manpower. And we all really, really need this rain, which is free. And in fact, we could use a lot more of it. The few tenths of an inch we're due today, and the dusting of snow we could get after the cold front passes through late today, will not get us far.

So far this winter BWI has recorded 9.21 inches of melted precipitation. That sounds like plenty, but in fact it is not quite keeping up with the norms for the December-through-February period. We are actually more than a quarter-inch short of the long-term average.

The real problem is that we entered this winter with a serious moisture deficit across much of the state - six, eight inches in many spots, and even more on the Eastern Shore. Baltimore's reservoirs had dipped to less than two-thirds of capacity by mid-December. That was no cause for alarm, perhaps, but it was a deficit that we nevertheless hoped to erase before the weather warmed up, evaporation increased, vegetation began to draw on soil moisture again and the heavy water-use season began.

That hasn't happened. Kurt Kocher, down at the city's Department of Public Works, says that while the reservoirs have done some recharging this winter - climbing to 78 percent of capacity by last week - they remain below par for the end of February.

"We would usually be higher than this," he said. "I know from experience you would be up around 90 percent, and in many cases pushing 100 percent this time of year ... We should be a lot further along. And we're not. We didn't have the tropical  (storm) season last fall. We just didn't get any of that." Nor have we gotten even normal rain or snow, much less a surplus.

The city continues to pump water from the Susquehanna River in a bid to conserve supplies in the reservoirs for this coming summer. It is currently running one pump, at a cost of $10,000 a day, pulling about 44 million gallons a day down the long pipe from the river. At times this winter the city was running two pumps, and moving about 90 million gallons a day. That's water that would otherwise have come from Loch Raven Reservoir, and Prettyboy above it. Instead, it will be available there in the reservoirs this summer, when demand peaks and water quality in the Susquehanna declines.

"I think we're doing okay," Kocher said. "If people continue to take steps to use water wisely, and do some basic conservation measures, that will be good for making sure everybody has an adequate water supply come spring. And also, you'll save money. So keep your fingers crossed."

While the northern tier of counties in Maryland is seeing normal soil moisture conditions, and groundwater is recharging, it remains low for this time of year. And much of Southern Maryland and the Lower Eastern Shore continues in drought.

So let's not hear any complaints about the drippy skies.

Posted by Frank Roylance at 10:28 AM | Permalink | Comments (0)
Categories: Forecasts
        

The sun will break through later today, and the temperature at BWI could touch 50 degrees. But it's just a tease. Spring is not here quite yet. Unseasonably cold, blustery weather returns later this week, with more gray, showery skies and a risk of some light snow showers by late Tuesday into Wednesday.  The weather service is even warning that "a few inches" of snow could pile up in counties west of the urban corridor.

So don't put those light boxes away yet, SAD sufferers.

First, we'll see high pressure and drier air building into the region today. The sun should break through and push today's highs at BWI above seasonal norms - as high as 50. But the barometer will then start to drop, and we could begin to see some rain before dawn Tuesday as a new low moves this way from Iowa and Missouri. It will be rain here, but could shift to freezing rain across Western Maryland.

As the low gets to the Ohio Valley tomorrow, we'll see increasing rain showers, amounting to perhaps a quarter-inch, forecasters are saying. Behind the rain there's another cold front, which will change the rain showers to snow showers Tuesday night.

The National Weather Service has posted a Hazardous Weather Outlook statement for Carroll, Montgomery, Howard and counties west of there, noting the possibility that snow showers could accumulate to an inch or two. Here's this morning's discussion.

The frontal passage will push winds to 24 mph Wednesday, with gusts to 41 mph. Temperatures on Wednesday night will drop to 20 degrees. Thursday will be cold, too, with a high about 38 degrees - 10 degrees below the long-term averages. But it should be sunny, at least.

After that, there's another Clipper due on Friday, with more rain. Temperatures will return to more seasonable levels, in the upper 40s at BWI.

A cloudy morning on Saturday would spoil the next, best flyover by the International Space Station, at about 6:10 Saturday morning. If the clouds part, we'll be able to watch the station fly almost directly over Baltimore. More on this later in the week as the forecast gets more reliable.

Posted by Frank Roylance at 10:56 AM | Permalink | Comments (1)
Categories: Forecasts
        

Only Marylanders would make such a fuss over this storm. Am I wrong? Am I missing something?

Here are the snow/ice accumulation reports from around the region.  Allegany County wins again with 2 to 6 inches reported way out west. But around here, nearly all of the snowfall is recorded at fractions of an inch. Ice is being measured in hundredths. Power outages at BGE have soared to a total of - 19. 

Okay. It is slippery underfoot this morning. Steps, stoops, sidewalks and parking lots can be tricky if you're not nimble on your pins. And maybe that's enough to make school officials think twice about opening the schools before their parking lots and sidewalks are treated. And the storm, after all, is not over yet.

The roads seemed fine when I ventured out. The salt trucks that woke me up in the wee hours have done their job.

But clearly there have been slippery spots. There have been many accidents this morning. If schools had opened, and just one of those accidents had involved a school bus, the decision-makers would have been burned at the stake.

So what do you think? Are we making too much of this storm? Or should we always err on the side of caution? 

And what about the forecast? The Winter Storm Warning remains in effect until 10 p.m. throughout the region. Forecasters are expecting "significant icing" today - as much as a quarter inch north and west of Baltimore, and a tenth of an inch south and east.

But it's a very complicated picture they're grappling with. Depending on where you are and when you venture out, you may see freezing rain, and later on, as more warm air works its way in and drives out the cold air at the surface, freezing drizzle, rain, drizzle and fog.

In fact, drizzle and fog will be the storm's most prominent feature by later today, according to this morning's forecast discussion.

Some rain and snow showers could persist into tomorrow - Saturday - as a secondary coastal low-pressure system forms and drifts up the coast and reinforces the cold air a bit, and pushes overnight lows back to the 20s Saturday night. But beyond that things begin to brighten up. Sunday and Monday should be sunny, with more seasonable highs in the 40s, to near 50 by Tuesday, when more rain enters the picture.

Posted by Frank Roylance at 11:10 AM | Permalink | Comments (28)
Categories: Winter weather
        

Enjoy the sunshine today, because you're not going to like tomorrow. The National Weather Service has posted a "Winter Storm Watch" for all of Maryland west of the Bay, effective from this evening through late Friday night.

UPDATE: The storm "watch" has been upgraded to a Winter Storm Warning, effective from 10 p.m. tonight through 10 p.m. Friday, from the Bay to Allegany County. The NWS forecasts light snow overnight, followed by freezing rain on and off into the evening on Friday. Expect a quarter-inch of ice and "substantial travel problems and power outages."  Sounds like a snow day to me, but stay in touch with your school - Sign up for The Sun's school closings alert service. See the end of this post for details.

Earlier post: This storm will likely start tonight as snow, but the thinking in Sterling appears to be that it will be largely an ice storm, with the potential for a quarter-inch of ice forming as the snow changes to sleet and freezing rain.  

We'll see clouds moving in from the southwest by this afternoon, the harbingers of the low-pressure system spinning up from the Texas Gulf Coast. Here's the radar loop.  And here's what the water vapor loop looks like.

If the forecast holds up, it will start as snow, and could accumulate an inch or two before the changeover begins.

Here's the setup: All this cold, arctic air that moved in with yesterday's Alberta Clipper is continuing to build. It's only 25 degrees here at Calvert & Centre streets as I write this. That sets up what meteorologists call a "cold air damming" scenario. This cold air is dense and heavy, and is not easily dislodged by the warm air advancing with the Texas storm.

So, we get warm, moist air aloft, dropping precipitation through the cold air layer at the surface. If the cold air layer is thick enough, we get snow. But as the warm air slowly erodes the cold layer, the cold gets thinner. The precipitation begins to fall as rain right through the thinning cold layer. It lands on sidewalks and tree limbs - where the cold air persists - and freezes in place. That's freezing rain. We get an ice buildup and - while it can be beautiful - all sorts of bad things happen.

Forecasters are having a hard time sorting all this out, and figuring out when the snow will change to sleet and freezing rain, and how much of each we'll get. But we should expect a couple of inches of snow and sleet by daybreak, followed by an extended period of freezing rain. Southern counties could see a change to all-rain, but the ice/rain line remains unknown.

The morning discussion seems to suggest the cold air will hang on longer than some of the computer models might suggest. We could get more snow than they're expecting: "If future (computer) runs come in colder again, or if observations come in colder than (computer) guidance, then (predicted) snow totals will need to be bumped up and ice accumulations toned down. Regardless, there's enough concern to justify continuance of the winter storm watch..."

At the tail end of tomorrow's storm, cold air moves back in, and any lingering precipitation on Saturday could be snow.

Here's AccuWeather.com's Henry Margusity on the forecast. And here's his precipitation map.

For those of you already wishing and hoping for school closings and delays Friday, and wondering why school administrators have to wait until dawn to make up their minds, we have a remedy.

The Sun's MarylandWeather.com will send you an email or a text message as soon as we receive word that a school or school system has decided to close or delay. Just visit our School Closings page, sign up and pick your school or schools. It's easy, free and it works. That's how my favorite teacher gets the word.

We can't make them decide any earlier, but we can get word to you as soon as we receive it. Just another service of your friendly hometown newspaper.

Posted by Frank Roylance at 10:45 AM | Permalink | Comments (7)
Categories: Winter weather
        

Sounds like plenty of Marylanders got a look at last night's eclipse, and many have left their impressions as comments on last night's post.

I was as surprised and delighted as anyone when I spotted the full moon on my drive home last night. Somehow there were still some flakes in the air, but the the clouds had cleared out beautifully, providing us with one of the best nights for a lunar eclipse that many of us can remember. Except for the 22-degree cold.

Baltimore's Streetcorner Astronomer Herman Heyn was on station in Charles Village. He reports something close to 100 people stopped by to see the eclipse through a friend's telescope, and Saturn through his. "People were thrilled by both," he said. "It revived my enthusiasm about lunar eclipses." After a series of them obscured by clouds here, "I'd sort of given up on them."

That's stargazing for you. You have to put up with clouds, and cold, and no-show meteor showers. But when everything aligns, as they did last night, the show is spectacular and unforgettable. I hope lots of kids got to see the eclipse last night. Mine are in their 30s now, and they both remember me waking them up one night when they were little, and shooing them to the back door to see a lunar eclipse. Spooky and exciting. 

Anyway, here's a photo shot last night by Hal Laurent from East Baltimore as the eclipse got underway. If anyone else has any good shots, send them to me and I'll post them.

In the meantime, here's a gallery of eclipse photos from around the world.

 Here's a shot of the eclipse by Alin Tolea. He used a Canon 40D camera with a 70mm Meade refractor telescope, and shot from Charles Village in Baltimore.

And here's what the sidewalk on St. Paul Street looked like as Streetcorner Astronomer Herman Heyn introduced visitors to Saturn. Thanks to Jessica Leibler for the photo.

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Posted by Frank Roylance at 10:26 AM | Permalink | Comments (6)
Categories: Cool pictures
        

The Clipper has moved offshore, and skies over Baltimore have cleared. So throw on a coat and head outside for a fine view of tonight's total lunar eclipse. It's the last one we'll see until Dec. 21, 2010. And we may get clouded out for that one.

So don't miss it. Take the kids out. They'll never forget it. Bring the binoculars. You can even watch from any east-facing window. The partial phase began at 8:43 p.m. or so, and the Earth's shadow is already creeping across the moon's disk. Totality will last from 10:00 p.m. until 10:52 p.m., and the event will be over by 12:09 a.m. For more information, check out the earlier posts and links.

When you come back in, leave a comment here and share the experience with everyone who figured it was snowing and went to bed without getting to see this celestial spectacular. Total eclipses of the moon, visible from start to finish under clear skies at a convenient hour are rare. Don't miss this one.!

Enjoy!

Posted by Frank Roylance at 8:45 PM | Permalink | Comments (27)
Categories: Sky Watching
        

Another disappointment for snow lovers and school kids. Today's Alberta Clipper looked pretty for a while. But unless you live in the western counties of Maryland, the accumulations did not impress. They don't call them clippers for nothing. They scoot by quickly. They're also pretty dry. There's not a lot of moisture out there in Alberta and northern Canada - certainly not like those storms that spin out of the Gulf and bury us.

Anyway, here are some snow totals from across the region today. Allegany County takes the prize.

Posted by Frank Roylance at 6:01 PM | Permalink | Comments (4)
Categories: By the numbers
        

Keep an eye on the roads this afternoon. As this Alberta Clipper approaches from the west, forecasters say, we should expect snow to begin in the western suburbs of Baltimore and Washington by noon, with snow reaching the urban corridor between 1 and 3 p.m.

Only in this winter of skimpy snow would we pay so much attention to this storm. But here we are, reduced to writing about 1 to 2 inches of snow. There will also be more wintry weather Thursday night into Friday. More on that in a moment.

The National Weather Service has posted a "Snow Advisory" for the almost the entire state west of the Chesapeake Bay, effective from 11 a.m. through 10 p.m. That means periods of snow will put a thin frosting on the roads and limit visibilities. Northern and western regions can expect the most snow. Salt crews are sure to be busy out there. The weather folks are urging caution while driving this afternoon. But then, shouldn't we ALWAYS be cautious while driving two-ton machines at 60 mph?

The impending storm is cranking up over southern West Virginia, and light snow has already moved into Frostburg. Our blue skies early this morning have changed over to a solid overcast. It's cold, and it feels like snow.

We could start to see flurries by lunchtime, but the real snow may not get cranking until early afternoon. By rush hour, it should be well underway. And with temperatures trending lower than earlier forecast, we will likely see all snow. I expect we will see some early exits from downtown this PM. Here's the radar loop. And a satellite shot.

The low will move offshore this evening, and skies should begin to clear. The NWS calls for clearing by "around midnight," which would be too late for those of us hoping to see at least part of tonight's total eclipse of the moon. With luck, maybe this thing will pick up speed and get out of here by 10. That would work out fine, since the period of totality starts at 10, and runs through 10:52 p.m. I'd be happy seeing half of that, and then the moon's slow return to full illumination by midnight.

Whatever sunshine we see Thursday morning will not last. By nightfall we'll be looking for more precipitation. The second storm of the week comes to us from the Texas Gulf Coast. It will track our way and collide with the cold, arctic air we're experiencing now.

Some of the computer models suggest the cold air will persist, giving us a longer period of snow. Others say we can expect a changeover to rain by Friday morning. Forecasters are hedging their bets for now, predicting snow and sleet for Thursday night, followed by freezing rain and sleet for Friday and Friday night. A good old Wintry Mix. AccuWeather is already out with a snow forecast map (left).

Looking deeper into the crystal ball, the author of this morning's forecast discussion from Sterling mentions "yet another storm" that computer models show forming in the Rockies reaching us by Monday night or Tuesday. Nobody is predicting accumulations on that one yet.

Posted by Frank Roylance at 10:53 AM | Permalink | Comments (1)
Categories: Winter weather
        

If tomorrow's predicted "Clipper" storm gets through the area in time, we could get enough clearing to catch at least part of the total lunar eclipse ocurring during much of the evening.

Wednesday's Sun will include a story on the event. For now, here are some online resources you can use to learn more about eclipses in general, and this one particularly.

Here is NASA's eclipse page, with loads of data on this eclipse and many others in the past and future. NASA has also posted a page and some videos explainers for this event. Click here. 

Never seen a lunar eclipse before? Here's a gallery of photos of past eclipses.

Have you heard about the lunar eclipse that saved Christopher Columbus and his crew? You can read all about it here.

And, if we;re clouded-out here, you can watch the eclipse live through the magic of Web video  - and explore a lot more eclipse lore - at SpaceWeather.com.

This is the first total eclipse of the moon visible from Maryland from start to finish since October 2004, and the last visible anywhere until Dec. 21, 2010. (That's 12/21/2010 for you numerologists.)

Lunar eclipses occur when the sun, the Earth and the moon line up, in that order. The full moon, in its orbit around the Earth, slides into the Earth's shadow and gradually grows dimmer and reddish in color. The transition moves from one side of the moon's disk to the other as seen from Earth. After a period of totality, the moon begins to emerge again from the shadow, and slowly regains its usual brilliance.

Here are the important times to remember fo this event: The partial phase of the eclipse begins at 8:43 p.m. EST. The moon will begin to slide into the Earth's "umbra," the darkest core of the shadow the planet casts into space. Over the next hour and a quarter, the moon will be gradually swallowed up by the shadow, and grow dimmer.

At 10 p.m., the moon's disk will be totally in shadow, taking on an eerie, reddish glow and strikingly spherical appearance. Binoculars will enhance the view.

Totality will last until 10:52 p.m., when the moon will begin to emerge again from the Earth's shadow. It will be restored to full, direct sunlight by 12:09 a.m. Thursday morning.

A number of local astronomers, groups and observatories are planning public viewing events. Here are some links to information:

Howard Astronomical League

Maryland Science Center

Maryland Space Grant Observatory at Johns Hopkins

Baltimore's Streetcorner Astronomer Herman Heyn will set up in the 3100 block of St. Paul St., in Charles Village, at 9 p.m., weather permitting. Here's hoping.

Posted by Frank Roylance at 4:57 PM | Permalink | Comments (0)
Categories: Sky Watching
        

Everybody knew yesterday's brief excursion into the 70s (it was 71 degrees at BWI for a short time) was a fluke, right? Now we learn just how flukey that was. The weather service is predicting snow, sleet, freezing rain and rain for the balance of the week. It's winter once again.

A reinforcing shot of cold air is going to move into the region today, bringing a chance for showers in the western counties, perhaps even some snow showers.

Tomorrow it looks like we're in the path of an Alberta Clipper - one of those not-so-fierce but potentially troublesome storms that come barreling out of central Canada. They don't bring a lot of moisture with them, but they can drop several inches of snow along a fairly narrow path.

Forecasters aren't sure quite what to expect from this one. They're pointing to similarities between this setup and the Clipper than dropped 4 inches of snow at BWI on Dec. 5. Some locations only got an inch, and others got as much as 7 inches from it.

The uncertainty with this event is the temperature and the exact path of the storm. "The thermal profile will be conducive to produce snowfall," they said in this morning's discussion, and "that snow is likely to come in a swath," with our region in a "transition zone."

Translation: They don't know how much snow we can expect, or where the snow/rain/slop lines will be. Stay tuned. Here's AccuWeather's take on it. Their Elliot Abrams is calling it the snowiest pattern of the winter, for whatever that is worth. Here's Henry Margusity's blog.

Skies could clear enough Wednesday night to afford us a peek at the total lunar eclipse, which begins around 8:30 p.m. and continues through midnight. (We'll have a story in tomorrow's Sun.)

And Thursday will start sunny, but that will be a brief pause before the next wintry weather arrives.

Forecasters say the cold air will remain at the surface, with highs Thursday and Friday only in the 30s, and lows in the 20s. Add in a surge of moisture and warmer air from the Gulf of Mexico as a low now forming over the Texas coast pushes northward, and we get interesting weather.

Forecasters, in their discussion this morning, said, "Thermally, it will be cold enough for snow at the onset. But as warm air advection (inflow) continues (we) foresee a mixed bag, as there should be an above-freezing layer aloft."

And all this wintry mess will stay with us from Thursday night into Saturday. Hang in there. Spring is just 4 1/2 weeks away.

.  

Posted by Frank Roylance at 10:32 AM | Permalink | Comments (3)
Categories: Winter weather
        

The predictions for tonight's flyover by the doomed USA-193 spy satellite have changed a bit from the times we published in the paper on Saturday. This is not unexpected, since the satellite's orbit is decaying rapidly. It is losing altitude, and speeding up enroute to a plunge into the atmosphere on or about March 11 - unless the Navy blasts it apart before then. The photo shows USA-193 at launch in December 2006. It failed soon after.

The weather forecast calls for "partly cloudy" skies tonight and tomorrow, so we have at least some chance of seeing this thing amid the clouds. Wednesday and Thursday look "mostly cloudy" from here, so our chances diminish as the week goes by.

So here are the latest times from Heavens-Above, calculated for Baltimore. To be sure not to miss it, be out there looking at least 5 minutes on either end of the sequence, just in case. Those who have already spotted USA-193 say it is brighter and faster than they anticipated. Good luck.

Tonight: (Monday) Look for USA-193 to appear above the southern horizon at 6:19 p.m., climbing more than halfway up the southeastern sky to pass straight through the constellation Orion at 6:21 p.m. From there it slips off to the northeast, disappearing at 6:23 p.m.

Tuesday: This will be a challenging observation, as the spy sat passes low to the horizon from west to south between 6:08 p.m. and 6:12 p.m. It will never get more than 18 degrees above the horizon.

Wednesday: USA-193 will rise above the western horizon at 6:04 p.m., move about halfway up the northwestern sky - just below Cassiopeia - by 6:06 p.m., then fly off toward the Big Dipper in the northeast.

Thursday: Another difficult pass, low in the northwest. Look for USA-193 to rise above the western horizon at 5:56 p.m., climbing no more than 27 degrees above the northwestern horizon by 5:58 p.m. From there it will slide off to the northern sky, and through the Dipper's handle by 6 p.m. This is the day the Navy plans to take its first shot at USA-193, so it may be space litter before this flyby.

If you spot it, please come back here, leave a comment and let us know what you saw. Thanks.

Posted by Frank Roylance at 11:42 AM | Permalink | Comments (7)
Categories: Sky Watching
        

And it won't. It may be sunny and 69 outside The Sun's newsroom this morning, and the temperature at BWI may have jumped 9 degrees in an hour. But there's a cold front coming and this spring-like weather will not survive the day.

UPDATE: It didn't. The mercury reached 69 degrees before noon at The Sun, then turned and fell to 57 degrees by 3 p.m. Earlier commentary follows.

The National Weather Service forecast calls for a high of, ahem, 58 degrees today. We're already well above that at the airport. (It was 69 at BWI late this morning. The record for this date is 75 degrees, set back in 1976.)

This springlike weather comes to us courtesy of a warm front pushing up from eastern Tennessee and Virginia.

Looks like sunny skies here for much of the day. But look for a wind shift  from east to west later on. That will signal the approach of the next cold front. It will take its sweet time getting in here. Forecasters says readings will finally begin to fall this afternoon, and sink to freezing by tonight. Western counties could see some snow showers. Here's AccuWeather.com

Tuesday will be much cooler- in the 40s, sunny and breezy - as the colder air works in from the northwest. An Alberta Clipper system is slated to move through on Wednesday bringing a chance for rain or snow showers, although forecasters don't seem too confident on that score. Their computer programs don't seem to agree on this one, so we may get no precipitation. The high on Thursday may be only 34 degrees - about 10 degrees below normal for this time of year at BWI.

Our next chance for wintry weather would come this weekend. The morning discussion from Sterling hints at a storm system forming along the Texas coast, but there are still too many uncertainties to get very specific about it. All they'll post is "a chance of snow or rain showers" for Friday and Saturday.

Posted by Frank Roylance at 10:39 AM | Permalink | Comments (0)
Categories: Forecasts
        

When it rains, it pours. If the clouds part at the right times in the next few days, Marylanders will have an opportunity to observe not only the very big, very bright and easily spotted International Space Station during passes over Baltimore, but also USA 193 - the now-notorious, formerly "secret" spy satellite.

USA 193 is out of control, and the Pentagon said yesterday it has elected to try to shoot it down in the coming weeks, using a modified missile. They're hoping to break the thing up so that it doesn't fall, whole, on people - a risk estimated at 1 percent. Critics worry that by blasting the satellite apart, the military will instead be creating thousands of smaller but still dangerous fragments that will plague satellites and manned spacecraft for years to come.

Whatever. The rest of us can only hope to get a glimpse of these space toys as they glide across our evening sky in the next few days. Here's how.

First up will be the ISS. Observers have been reporting that the $100 billion station is so big now that it has become noticeably brighter in its flyovers. Many people have been spotting it in very bright skies, very close to sunrise or sunset. The photo above was taken some time ago, before the station reached its current configuration.

Below, left, is an image shot Feb. 9 by Josef Huber, at the Munich Public Star Observatory in Germany. The image on the right is a model, showing more clearly what the telescope saw.

You can see a video of the sequence, here. And here is a gallery of ISS images from the same observatory.

Our first opportunity to see the ISS will come Friday evening. The forecast is not promising - "mostly cloudy" at this reading. But here are the specifics, just in case: Look for the station to rise in the northwest at 6:16 p.m., appearing like a bright star, moving briskly toward the east as it heads from the Great Lakes toward the tip of Long Island. If it has multiple lights, or colored lights, it's an airplane. Keep looking.

The station is flying at about 17,500 mph, and a little more than 200 miles above the Earth. The ISS carries a crew of three, while the attached shuttle has a crew of seven.

The station will climb no more than a third of the way up the northeastern sky as it flies over New York's Hudson River Valley, passing just above the Big Dipper at about 6:19 p.m. Then it will fly off toward the eastern horizon, disappearing there at 6:22 p.m.

On Saturday evening, skies should be clear. The ISS will appear above the northwest horizon again, this time at 6:37 p.m., climbing high into the southwestern sky by 6:40 p.m. as it passes over central Virginia. From there it will zip off toward the southeast, passing close to the bright star Rigel at the foot of the constellation Orion before vanishing at 6:42 p.m.

But wait! There's more! Look for the waxing moon high overhead, alongside reddish Mars. No extra charge.

Next up is USA 193. I haven't seen this bird yet, so I can't say for sure how bright and easy to spot it will be. But the predicted magnitudes (apparent brightness) place it among some of the brighter (though not the brightest) winter stars. So unless you're in the city, it should be visible to most people with decent vision. Keep in mind that this bird is falling. It's orbit is decaying, so the times in the following predictions may, especially by late in the series, be thrown off by a minute or two. Allow time on either end of the predictions for such an error.

So, the first pass high enough to be easily tracked will come on Sunday evening. The forecast is poor, with an 80 percent chance for showers. But, if we get lucky, look for the spy satellite to rise above the southern horizon at 6:28 p.m., climbing to a little less than a third of the way up the southeastern sky by 6:30 p.m. It will skim just above the bright star Sirius before racing off toward the eastern horizon, disappearing there at 6:31 p.m.

Monday night's forecast is also doubtful - mostly cloudy. But, just in case, look for the USA 193 to rise above the southern horizon at 6:22 p.m., climbing higher this time - rising 56 degrees (more than halfway up) into the southeastern sky and passing just above Orion at 6:24 p.m. before sliding off toward the northeast and vanishing at 6:26 p.m.

Tuesday evening's pass by the doomed spy satellite will be the best of the batch. The forecast from this distance is excellent - clear skies. Look for the satellite to rise from the southwest at 6:15 p.m., climbing swiftly to more than 70 degrees above the northwestern horizon at 6:17. It will fly above the W-shaped constellation Cassiopeia, then head off toward the northeast, disappearing there at 6:20 p.m.

The last convenient flyby for USA 193 will come Wednesday evening. The satellite will rise above the western horizon at 6:08 p.m., climbing to about a third of the way up the northwestern horizon at 6:10 p.m. It will pass below Cassiopeia this time before slipping away toward the northern horizon, disappearing at 6:14 p.m.

That's it. If you manage to spot these objects once or twice you can consider the enterprise a success. Good luck. And, if you want to track this sort of prediction on your own, I recommend visiting the Heavens-Above.com website. You can program the satellite predictions for your own location, and there's a wealth of other information there for the backyard stargazer. It would be wise to use Heavens Above to recheck the predictions, in case of orbital decay.

Posted by Frank Roylance at 11:27 AM | Permalink | Comments (1)
Categories: Sky Watching
        

A few flakes fell on Baltimore on this date five years ago. It wasn't much - just 2.4 inches by the time it ended. But it turned out to be just a prologue to the worst snowstorm since they began keeping snow records for Baltimore in 1883.

The first snow fell on a Saturday - the weekend before President's Day. It was a nuisance, but the city handled it well. It was the forecast that worried us more. Meteorologists said a new storm was gathering steam, and threatened to dump another 7 inches or so the next day. They were a tad off in the guesstimate.

By the time that Sunday, the 16th, ended, there was another 21.8 inches of snow on top of the first storm's leavings. The airport was buried. The roof on the B&O Railroad Museum in Baltimore had collapsed. Cars were buried everywhere. Highways and streets were narrow, rutted paths if they were open at all. It would take most residents days to dig out, and often even more time waiting for plows to show up. And when they did, they resealed everyone's laboriously dug openings to the outside world.

And even that wasn't all. The next two days - Monday and Tuesday - saw another 4 inches accumulate, bringing the four-day total to 28.2 inches. By the time the long, snowy month finally ended, the February total came to 40.5 inches. It was the snowiest month since records began, and the second-snowiest season on the books.

You can re-read some of The Sun's coverage of the Presidents Day Weekend Storm of 2003 by clicking here. There is also a gallery of Sun photos of Marylanders battling the storm. For a listing of the greatest snowstorms on record for Washington and Baltimore, click here. There are some narratives of great Maryland winters, and a wealth of winter statistics from the NWS, here.

And we invite you to share your recollections of The Big One, by entering a comment, below.

Posted by Frank Roylance at 5:47 AM | Permalink | Comments (7)
Categories: History
        

Yesterday's snow, sleet, freezing rain and rain pushed us over the 30-year average for precipitation in February. But we still haven't done much to reverse the 9-inch deficit we've accumulated since last April.

The NWS instruments at BWI recorded 1.44 inches of precipitation on Tuesday and Wednesday. That brought the month's total to 3.27 inches, a quarter-inch over the 30-year average of 3.02 inches for February. But deficits for seven of the previous nine months have left us with less reserve than we want heading into a new growing season and summer heat.

Here's how the precipitation totals stack up as departures from the longterm averages. Negative numbers are deficits, positive numbers are surpluses:

May 2007:  -2.95 inches

June 2007:  -1.23 inches

July: 2007:  -0.54 inch

August 2007:  -0.66 inch

September 2007:  -3.63 inches

October 2007:  +2.69 inches

November 2007: -1.60 inches

December 2007:  +0.68 inch

January 2008:  -2.00 inches

February 2008*: +0.25 inch

Total: -8.99 inches

* through 2/13/2008

Here's this week's Drought Monitor map, which does not reflect the recent precipitation.. 

Posted by Frank Roylance at 2:32 PM | Permalink | Comments (0)
Categories: Drought
        

Tired of being just a passive victim of the weather? Well, you can take an active role in observing the weather, and make a real contribution to science in the bargain. Get involved with CoCoRaHS, an organization of volunteers dedicated to recording and reporting on precipitation across the United States.

The group, the Community Collaborative Rain Hail and Snow Network, is looking to expand, and they're meeting Friday, at noon, at the NOAA offices in Silver Spring to spread the word. Here's their release: 

Posted by Frank Roylance at 2:03 PM | Permalink | Comments (0)
Categories: Events
        

The dusting of snow we were forecast to see overnight stayed well to the south of Baltimore. But the Lower Eastern Shore saw enough to whiten the beach at Ocean City and to close schools in Dorchester County for the day.

Here's the view from Phillips Beach Plaza Hotel this morning. Observers at Salisbury-Wicomico County Regional Airport reported light snow between 2 a.m. and 6 a.m.  

The snow curling around onto the back side of the cold front has now departed, moving out to sea, and high pressure is building into the region. That means sunny skies today and much of tomorrow, but with more seasonable temperatures today, warming into the 50s tomorrow (Friday).

Late tomorrow, another cold front will push through, dropping temperatures on Saturday. The high will stick in the 30s, with an overnight low in the mid-20s early Sunday.

Then clouds move in again, with rain likely by Sunday night. Presidents Day will likely see showers, too, with a high warming back into the 40s until yet another cold front drops things back into the 30s for Tuesday and Wednesday.

Posted by Frank Roylance at 10:06 AM | Permalink | Comments (0)
Categories: Winter weather
        

The snow/sleet/freezing rain/rain storm is moving off the coast now. It turns out to have been quite a wet one. Here are some (unofficial) precipitation readings from around the region, as reported by CoCoRaHS. You can multiply each number by 10 to get a rough estimate of how much snow we would have received, had the atmosphere aloft been colder:

Cockeysville: 1.90 inches

Bel Air:  1.82 inches

Ellicott City:  1.77 inches

Columbia:  1.59 inches

Elkridge:  1.49 inches

Havre de Grace:  1.38 inches

Bowie:  1.25 inches

Pasadena:  1.14 inches

Taneytown:  1.06 inches

Frederick:  0.80 inch

For more readings in more locations, click here.

Posted by Frank Roylance at 5:48 PM | Permalink | Comments (0)
Categories: By the numbers
        

Editors are already asking whether tonight's expected snowfall will be enough to justify running the "physiology of snow shoveling" story I wrote in December. Alas, no. Forecasters say that, while the rain today will likely change to snow as the next cold front passes through, and a storm center intensifies off the Virginia coast, we're slated for just "a dusting to a half inch" in the DC-Baltimore area.

Maybe we'll stow that article away for next year. There is no significant snow in sight for us, although we will see some more much-needed rain today, Friday night, and again Sunday, if the forecast holds up. (Thursday and Friday should bring sunshine and highs in the 40s and 50s.)

There are some who say that, simply by writing the shoveling story, I have single-handedly kept shovel-worthy snow away this season. Of course, as a mild-mannered reporter for a Great Metropolitan Newspaper, I claim no such powers.

Precipitation that began yesterday as snow, sleet and freezing rain has so far dropped 1.25 inches at Baltimore-Washington International Thurgood Marshall Airport. I'd tell you how much we received here at The Sun, but our rain gauge is frozen, and only 0.18 inch has trickled through so far. Ditto for the gauge on the WeatherDeck in Cockeysville, where my favorite teacher has another day off. 

The total at BWI brings precipitation for the month to about 3 inches. It's a good and welcome total, but not yet the surplus we still need.

Here are some snow and ice measurements from across the region. Looks like Frostburg wins the snow prize, with 5 inches.  Virginia saw the heaviest ice accumulations.

Posted by Frank Roylance at 10:36 AM | Permalink | Comments (1)
Categories: Forecasts
        

Many residents of northeastern Maryland felt a series of tremors this afternoon, and Joe MulQueen figured the shaking his house took must have been an earthquake. "It sounded like an explosion, but the entire house shook," he said.

But area seismographs were quiet. The shakes were the result of explosions at the U.S. Army's Aberdeen Proving Ground. Base spokesman George Mercer said the blasts included three "static detonations" at the facility's Edgewood Area. "And they were loud," he said.

A temperature inversion - a layer of warm air atop a layer of cold air at the surface - caused the sonic energy to reflect back to the ground rather than dissipate into the sky above. That just made matters worse, he said.

The noise and shaking was heard and felt from Perry Hall to Middletown Del. Mercer took 30 calls from concerned citizens. About 20 of them were complaints, the rest just expressions of concern and curiosity. 

There is more on the incident at Baltimoresun.com and there will be an article in Wednesday's print editions. Break a buck and buy one. Our kids gotta eat, too.

Posted by Frank Roylance at 5:49 PM | Permalink | Comments (1)
Categories: Events
        

I guess I knew it was a possibility. But in this winter of snow scarcity, I was surprised to see a white dusting on the WeatherDeck this morning. That fell between 1 and 3 a.m. Frostburg got more than 3 inches. Here are some other snow reports.

More nasty weather is headed our way as the disturbance redevelops this afternoon and moves across Virginia. So if you can, get to the polls early.

Temperatures seem stuck in the mid-20s at this writing, so any precipitation that comes along this afternoon could fall as more snow or sleet or freezing rain. Here's the radar loop.  And here's how AccuWeather.com sees the precip types.

Bridges and overpasses could get a glaze of ice in the more northern and western counties. A Winter Weather Advisory has been posted for that region. Road crews have been busy heaping salt on everything this morning, so the roads should be safe.

Forecasters are having a difficult time with this one. Computer models disagree on the amount of moisture arriving with this system, and when the wintry mix will switch over to all rain. The folks at Sterling seem to be going with the models that predict we'll have all rain by this evening as more warm air moves in and shoves aside the lingering arctic air at the surface.

Wednesday looks like more precipitation - all rain this time, and mostly in the morning hours. We could see up to a half inch as the storm taps into Gulf moisture. Then another cold front will move through, drying us out for Thursday and part of Friday, when rain chances rise again. Saturday looks better, but more rain/snow risk returns Sunday and Sunday night. 

Posted by Frank Roylance at 10:20 AM | Permalink | Comments (1)
Categories: Forecasts
        

Cold wind straight out of arctic Canada raked the region yesterday, toppling trees, snapping power lines and launching tons of leaves, branches and trash into the air. It also threatened to shove small cars and empty trailers off the highway. I know. I was in one of them. (A small car, that is.)

Here's a long, but by no means complete list of wind-related incidents across the region. And here's the latest accounting of power outages that BGE crews are scrambling to repair.

Temperatures at BWI dropped to a low of 13 degrees just before dawn this morning. It was the second-coldest morning of the season, after the 8-degree low on Jan. 21. (December's low reading was 14 degrees, on the 7th.

It was 11 degrees out on the WeatherDeck in Cockeysville when I got up. That was the night's low. Here are some other readings from across the state.

Ordinarily,  an outbreak of arctic air like this, in the middle of February, would be a setup for a big snowstorm. The cold air is dense, and heavy, and difficult to dislodge. The first coastal storm that runs into it should drop 10 or 20 inches of snow on our heads.

But alas, this cold doesn't seem destined to last. And, while there is a storm headed this way for tomorrow and Wednesday, it's coming from the Ohio valley, so it is likely to affect us mainly with rain. After a cold day today, stuck in the low 30s, we're headed for the 40s for the rest of the week. Here's the Hazardous Weather Outlook for this area. Here's how AccuWeather.com's Elliot Abrams maps out the precipitation:

I say mainly rain because forecasters at Sterling are hedging a bit. The computer models are having some trouble with the strength and timing of the storm system, and exactly when the cold air we're in now will be forced out.

Hence, the morning's discussion says stuff like this (my edits, for clarity, in parentheses):

"Assuming it (storm) comes Tuesday morning-midday (forecast area) will be recovering from a cold start ... So initial precipitation most likely to be snow" (before warm air erodes and it all changes to rain)."

"Am somewhat concerned about northern tier of (counties in Maryland, W.Va. and Virginia) ... Setup hinting that cold air may hang on longer than (forecast) ... There could be a period of freezing rain, maybe for several hours. Maybe for the entire afternoon into evening. From this perspective, don't think we will be able to avoid a headline with this event, especially (Cumberland-Hagerstown)."

The forecast also mentions  a "chance" of more snow or rain Saturday night, the 5th anniversary of the start of the biggest snowstorm on record for Baltimore, back in 2003.

Posted by Frank Roylance at 10:35 AM | Permalink | Comments (0)
Categories: Events
        

Watch those smokes, folks. The National Weather Service has posted a "Red Flag Warning" from Arundel and Montgomery counties wouth into Virginia, as high winds and very low humidities turn grass, brush and leaf litter to tinder. It's the red zone in this map.

The forecast calls for winds gusting as high as 55 mph this afternoon. The really cold arctic air moves in late today, sending overnight lows into the teens tonight. This will be very dry air. Here's how the forecasters out at Sterling put it in their discussion yesterday:

"FOR SNOW LOVERS THIS WILL BE A WASTE OF COLD AIR. HIGH PRESSURE TO BUILD
INTO THE REGION SUNDAY NIGHT BRINGING VERY DRY (AND COLD) AIR. I CAN`T
RECALL THE LAST TIME I PUT SUBZERO DEWPOINTS IN THE ZONES. LOTS OF STATIC
ELECTRICITY WHEN YOU WALK AROUND AND TOUCH ANYTHING MON. MORNING."

Sub-zero dewpoints mean the air is so dry that temperatures would have to sink below zero before the air would become saturated, and the moisture condense and fall as snow. The dewpoints in Baltimore tonight will be minus-2 to minus-4 degrees.

I'll have to be careful with static charges. I've zapped my laptop once before with a spark from my finger to the screen. It went dark and I had to reboot.

Posted by Frank Roylance at 9:18 AM | Permalink | Comments (0)
Categories: Watches and warnings
        

My clear-sky alarm went off this morning, alerting me to good star-gazing conditions in Baltimore after 9 p.m. tonight. Unfortunately, the International Space Station will not be in our skies, so we will NOT have an opportunity to watch the ISS and the shuttle Atlantis soar over Baltimore one after the other.

Still, the clear weather offers us a good chance to see Mars again - high overhead, still a bright, ruddy "star" in the evening sky. And pale-yellow Saturn is rising earlier each night. It's low in the east by 9 p.m., moving toward opposition on the 24th. At that point it will be rising at sunset, and climbing high in the sky by midnight. By month's end, Saturn will be as close as it will be all year, prime time once again for viewing the majestic planet and its rings through backyard, streetcorner or observatory telescopes. You'll never forget your first look at this iconic orb.

In any case, these cold, crisp winter evenings are always a great time to go outside and re-acquaint ourselves with the bright stars and constellations of the northern winter sky. Orion, left, with its easy-to-spot three-star "belt" and, just below it, the fuzzy smear (red in this image; binoculars help) of the Orion nebula; brilliant Sirius (the brightest true star) below and to the left of Orion; lonely Procyon higher and more to the left; the twins of Gemini, Castor and Pollux.

For those who have come to enjoy watching $100 billion of your hard-earned tax dollars at play in the night sky, the International Space Station and attached shuttle will make several convenient evening passes over Baltimore next week, between the 13th and the 16th. If NASA uses Atlantis to boost the station's orbit, as expected during this mission, the flyby times will change somewhat from their current predictions. So watch this space next week for details.

The weather? Look for a chance of showers tomorrow, and a sharp, quick cold snap Sunday night and Monday. But before and after that, we can expect mostly seasonable temperatures. There is some talk of snow showers to our north and west, but nothing to worry about down here in the urban corridor. Still no real winter in sight.

Posted by Frank Roylance at 11:05 AM | Permalink | Comments (0)
Categories: Sky Watching
        

The spring-like cold front that triggered dozens of deadly tornadoes across the South crossed Maryland late yesterday without much fuss. Baltimore-Washington International Airport saw winds of 26 mph, with gusts to 40 mph around 11 p.m. as the weather boundary passed.

The Sun's anemometer, somewhat sheltered by buildings, spiked to 25 mph around midnight. But there was none of the predicted heavy rain.

We had two hundredths of an inch of rain here at Calvert & Centre streets. It rained very hard for a brief time out on the WeatherDeck in Cockeysville. But when it ended we had just five hundredths of an inch in the gauge.

Reagan National Airport in Washington collected 0.14 inch of rain, but Dulles, out in northern Virginia, had none. Hagerstown reported 0.31 inch, the most I could find in the immediate area. The Inner Harbor saw just 0.03 inch. Here are some other readings from across the state. McHenry, out in far western Maryland, reported an inch of rain, perhaps the most anywhere in the state. Here's the CoCoRaHS report.

We're still well ahead of the curve for February, thanks to the heavy rain - 1.8 inches - on the 1st. But the long-range picture is still dry. Here's this morning's Drought Monitor Map. We still have not made up the deficits accumulated after April of 2007. The southern counties of the Eastern Shore are hardest-hit.

Streamflow, however, looks much improved. So do some of the USGS groundwater monitoring wells. Here's one near Granite, in Baltimore County.

Posted by Frank Roylance at 10:49 AM | Permalink | Comments (0)
Categories: Events
        

Records have been tumbling all over the place this afternoon.

At BWI, we reached a high temperature of 72 degrees between 1 and 2 p.m., besting the old record of 72 degrees, set on this date in 1938.

There was also a new high temperature record at Reagan National Airport. It was 74 degrees there this afternoon, breaking the 69-degree record set in 1938.

Dulles International also set a new record of 71 degrees today. They broke the old record of 66, set in 1990.

That's all about to come crashing to an end. Here is the Hazardous Weather Advisory posted for this area:

"A STRONG COLD FRONT WILL MOVE EAST ACROSS THE MID ATLANTIC THIS AFTERNOON.
THE COLD FRONT IS EXPECTED TO APPROACH THE METROPOLITAN AREAS OF
WASHINGTON DC AND BALTIMORE...THE TIDAL POTOMAC AND CHESAPEAKE BAY
THIS EVENING BETWEEN 7 PM AND 11 PM. SHOWERS AND THUNDERSTORMS
WILL ACCOMPANY THE FRONTAL PASSAGE. SOME OF THE THUNDERSTORMS WILL
BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS...IN EXCESS OF 70
MPH...AND VERY HEAVY RAINFALL. IN ADDITION...THERE IS THE
POTENTIAL FOR ISOLATED TORNADOES."

Posted by Frank Roylance at 5:14 PM | Permalink | Comments (0)
Categories: By the numbers
        

Jon Goldberg awoke to a frosty morning in Elkton on Dec. 31. went out to his car, and captured this image of Jack Frost's handiwork on the windshield. Amazing what water vapor, cold glass and ice crystals can do.  Thanks to Jon for sharing it. 

Here are two more.

Posted by Frank Roylance at 4:59 PM | Permalink | Comments (3)
Categories: Cool pictures
        

A surge of warm air from the South, pushing in ahead of a potentially dangerous cold front later today, has driven temperatures at BWI close to a new record this morning.

It was already 66 degrees at BWI at 7 a.m. Our weather station here at Calvert & Centre streets is reading 69 degrees. The record high for this date at BWI is 70 degrees, set back in 1938. With just another little surge of air from Dixie, we will set a new record for today's date.

We nearly set an overnight record, too. The low at 4 a.m. this morning at BWI was 45 degrees. That was just two degrees below the record high minimum temperature for this date - 47 degrees - set in 1991.

After that low was reached, the temperature at the airport jumped 15 degrees, to 60, in just an hour.

All bets are off this afternoon, when a cold front - the same one that has triggered a deadly rash of tornadoes across the South overnight - will cross our region. Forecasters at Sterling say the excitement will begin here after 3 p.m., as showers, thunderstorms, heavy rain and gusty winds mark the frontal passage. Isolated tornadoes are possible. Here's the radar loop.

We can expect up to a quarter-inch of rain, and more in some storm cells. The rain and storms will continue into the early evening, with another qaurter-inch of rain possible.

After the front passes by, we'll notice a wind shift from the southwest to the west, the air will begin to dry out and the skies will clear.

Tomorrow will be sunny and cooler, but daytime highs will still be near 50 degrees - well above the 43-degree norm for this time of year at BWI.

Another cold front will scoot by late on Friday, bringing a bit more rain and dropping our weekend temperatures to the below-normal range. The high on Sunday won't get much above freezing, and the overnight low Monday morning will sink into the teens in many locations.

Posted by Frank Roylance at 10:39 AM | Permalink | Comments (0)
Categories: By the numbers
        

There's a warm front on the move through our area today, and by tomorrow we could be threatening a 70-year-old record high temperature for Baltimore.

Forecasters say the high at BWI this afternoon could reach 63 degrees. It was 75 this afternoon in Fredericksburg, Va. But as warm air continues to flow in from the south and southwest, temperatures here tomorrow could reach 69 degrees. That's just one degree shy of the 70-degree record set for Baltimore on a Feb. 6 in 1938. A little sunshine in the afternoon could push us into record territory.

The 30-year average for the 5th and 6th of February in Baltimore is 43 degrees. So we're cruising for a 20-degree departure from the norm this week. Tonight's low may stall at 55 degrees - 12 degrees warmer than the average HIGH for the date. Here's AccuWeather.com's take.

That's a big break for homeowners struggling to keep up with their heating bills this winter. Demand for heating energy, as measured by the degree-day count, is running about 11 percent behind the long-term average for Baltimore.  That's money in our pocket.

But enjoy it while you can, because it won't last. A storm system headed for New England will drag a cold front across Maryland late Wednesday. It could come with showers and thunderstorms in the late morning or early afternoon. As much as a quarter-inch of rain could fall.

Behind the front we'll see clearer, drier weather, and temperatures will fall back to more seasonable numbers. By Saturday night we'll be looking at lows in the mid-20s again. Sunday and Monday won't get out of the mid-30s, if the forecast holds up. That would be 10 degrees below the norms.

The colder air, in turn, could set us up for some wintry weather if the right storm comes along. And next week is, at least statistically, the snowiest of the year. For now, 2007-08 is shaping up as the least snowy in six years. We've had just 7.2 inches at BWI. Our long-term average is 18 inches.

Posted by Frank Roylance at 11:10 AM | Permalink | Comments (2)
Categories: By the numbers
        

We're in for a few days of mild, showery weather before February returns later this week. Sort of like a shot of April, with a February chaser. And some sunshine, finally, by Thursday.

Temperatures Tuesday and Wednesday will rise into the 60s, if the forecast holds up. That's 20 degrees above normal for Baltimore at this time of year. The overnight LOW Tuesday into Wednesday will be 54 degrees, which is 10 degrees warmer than the normal HIGH for the first week of February. Go figure.

The cause is a large high, spinning clockwise over the western Atlantic, and a strong low over the Great Plains, spinning counterclockwise. That puts us in between with both systems driving air northward out of the south or southwest, like a wet sheet through a ringer. (Yes, I remember ringer washers. It was my grandmother's, not mine thank you very much.)

While we enjoy readings in the 60s in Maryland, parts of Central Virginia could reach the 70s on Tuesday.

The record for a Jan. 5 at BWI is 73 degrees, set in 1991.

Wednesday will bring the next cold front in from the Great Lakes, bringing more showers. Up to a half inch is possible, according to NWS forecasters. But we could see highs in the 60s before the front drives through later in the day Wednesday.

Once that's past, we'll go back to drier conditions and more seasonable temperatures, in the 40s into the weekend, with overnight lows around freezing.

The rain won't do much to recharge the water tables, only a tenth of an inch or less today and a similar amount tonight. Wednesday could produce up to a half-inch, though. That would help.

In any case, it was last week's rain that really made a difference. BWI saw 1.8 inches. We had 2.3 out on the WeatherDeck in Cockeysville. Here are some other measurements from around the region. Here's how one Baltimorte County well responded:

For the latest USGS rundown on how our water situation looked at the end of January, click here.

Here's how a monitoring well in Wicomico County has been looking in recent weeks - record lows. The southern Shore is facing severe drought conditions, and got only a limited boost from last week's rain:

Posted by Frank Roylance at 10:48 AM | Permalink | Comments (0)
Categories: Forecasts
        

A NASA study on rainfall has used satellite data to discover that, in the Southeast at least, air pollution gives summertime storms an extra "kick," producing a tendency for more rain during the work week than on weekends.

The key seems to be the particulate matter in air pollution from cars, factories and other workday sources. Water vapor condenses around these "seeds," and fuels more intense storms, which drop more rain.

You can read more about it here.

Posted by Frank Roylance at 9:51 AM | Permalink | Comments (0)
Categories: Science
        

Okay, Space cadets... I have my doubts about whether this storm will clear out in time, but here are the specs for tonight's Baltimore flyover by the International Space Station. If we can see it, it will be a very fine pass. The ISS will follow the same track as Wednesday's flyby, but this time it will be brighter, and it will be visible across the entire sky.

If the clouds part, look for a bright, star-like object rising above the southwest horizon at 6:07 p.m. and climbing almost two-thirds of the way up the northwestern sky. (If it has multiple lights, colored lights, or a blinking strobe, it's an airplane. Keep looking.)

The ISS will pass through the W-shaped constellation Cassiopeia at about 6:10 p.m., and head off toward the northeast, disappearing from view near the Big Dipper at 6:13 p.m.

The station, with three people on board, is orbiting the Earth at 17,500 mph, just over 200 miles above the surface. As we pick it up here, it will be high over northern Alabama, passing northwest of Baltimore and moving off toward coastal Maine, New Brunswick and Newfoundland. Here's the ground track map, from http://www.heavens-above.com

Posted by Frank Roylance at 2:51 PM | Permalink | Comments (0)
Categories: Sky Watching
        

This new storm has already dropped more than a half-inch of rain on instruments here at The Sun, and out on the WeatherDeck in Cockeysville. Officially, out at BWI, they've clocked just over eight tenths of an inch. If you accept the rule of thumb equating an inch of rain to 10 inches of snow (a rule that is not always reliable), we could have been looking at up to 8 inches of snow this morning, with more to come.

UPDATE at 3 p.m.:  We've topped 1.1 inches here at The Sun. BWI has exceeded 1.3 inches. Here are the watches and warnings.

EARLIER: Now try to imagine all this rain as snow, falling on Maryland's Presidential Primary day, Feb. 12. Nice mess, huh? That sort of thing never happened when we voted in May. But I digress.

Icing does not seem to be affecting BGE customers, but Allegheny Power, to our west, has quite a few customers in the dark in West Virginia and Pennsylvania.

Radar suggests we'll catch a little break this morning, then see more rain in the afternoon.

Here are some more rainfall counts from around the region, as gathered by the NWS. Here are more for Maryland, from volunteers with CoCoRaHS.

Freezing rain to the north and west of the urban corridor produced enough ice to worry school officials. Frederick, Carroll and Harford schools elected to close, and Baltimore County shuttered schools in the Hereford Zone, leaving my favorite teacher with nothing to do today.

Remember, you can get all regional schools closing information from BaltimoreSun.com, and even have us email you alerts and updates. Just click here. 

Not much risk of closings next week. They're expecting sunny skies and highs near 50 for the next three days, and near 60 on Tuesday. The long-term forecast holds some more precipitation, all of it liquid. Forecasts of a mild, mostly snow-free winter appear to be holding up well.

Posted by Frank Roylance at 10:15 AM | Permalink | Comments (2)
Categories: By the numbers