Saturday, February 24, 2007
Complex Winter Weather Event Taking Shape
Nasty Mix Possible Sunday
Team Forecast @ 4:45 PM
*Winter Storm Warning from 4am SUN to 4am MON**Freezing Rain Advisory from 4am SUN to 4am MON*
A storm developing in Midwest will head east today, overspreading mixed precipitation across the Washington, DC area by tomorrow morning. Today will be mostly sunny and brisk with highs in the low 40s. Tonight temperatures will drop below freezing setting the stage for some icy precipitation on Sunday. Our current expectation is that this will be a low to medium impact event for the immediate metro area with an eventual changeover to rain probable.
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Frequently Asked Questions
When/where will the heaviest frozen precipitation fall? Most likely in late morning to early afternoon on Sunday, with the highest risk of accumulations of frozen precipitation in the north and west suburbs (places like Manassas, Leesburg, Centreville, Gaithersburg, Frederick).
Will the snow/ice accumulate? In the colder north and west suburbs, the mixed precipitation will accumulate sooner and quicker. In the metro area, some accumulation is possible particularly on untreated surfaces during heavy periods of precipitation before noon Sunday.
When will travel be most difficult? From Sunday morning into the early afternoon.
Could there be power outages due to ice? Some scattered power outages are possible in the colder suburbs north and west of DC but this probably won't be as big a problem as the last storm due to slightly warmer temperatures and less wind.
What about precipitation type? This is the most complex aspect of this storm to forecast. The precipitation may briefly start as snow for much of the area. There is some potential for light accumulations of up to an inch particularly in the north and west suburbs. Sleet may be the predominant precipitation type in the metro area through early afternoon with some freezing rain possible as well. The exact distribution of sleet and freezing rain is difficult to predict. During the afternoon, it is likely the precipitation will change to rain or drizzle in the metro area. Unlike the last storm, a continuous feed of cold air from the northeast is not likely and temperatures will likely get above freezing, though it's possible this doesn't happen until the bulk of the precipitation has fallen.
When will conditions improve? Most likely mid to late afternoon on Sunday, as precipitation begins to taper and temperatures rise above freezing. However, in areas north and west, light freezing drizzle may linger overnight Sunday.
Could it fizzle out? Yes. Storms coming in from the west with marginal cold air often underperform in the DC area. Several things could happen that reduce the storm's impact. 1) A later storm arrival Sunday morning may allow temperatures to rise above freezing before the precipitation starts. While temperatures could briefly drop back below freezing during the precipitation, just marginally freezing temperatures coupled with late February insolation (sunlight through the clouds) could reduce the risk of snow/ice accumulation in the metro area. 2) As the primary low to the west weakens and the new coastal low forms, we could get "dry slotted" beginning late Sunday morning reducing precipitation amounts. 3) The cold air erodes more quickly than expected due to warm air aloft mixing down to the surface and/or surface winds shifting more quickly to easterly -- resulting in mostly rain.
Could the storm bring more snow or ice than expected? Yes. It's possible, that like with the last storm, the cold air holds a bit longer than expected in the metro area resulting in a more significant icing event. However, the supply of cold air for this storm is not as impressive so it's very unlikely this storm will have a comparable impact.
What are other forecasters saying? The National Weather Service has issued a Freezing Rain Advisory for the area suggesting the likelihood of up to 0.2" of ice accumulation.
What's the bottom line? A low to medium impact winter weather event is likely, with some snow/ice accumulation possible, particularly in the colder suburbs north and west of the city (north and west of western Fairfax County and central Montgomery county).
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Friday, February 23, 2007
Windy Cold At Bat; Wintry Mix On Deck
Steve Scolnik @ 5:00 PM
*Winter Storm Watch in Effect Late Saturday Night Through Sunday Night*
Now
Windy, cold. We're in the late innings, but winter isn't ready to put away the bat just yet. Winds peaking as high as 55 mph overnight have made it feel a lot colder than the near 40° temperatures this afternoon in the Washington metro area, especially after the relatively balmy experience of 3 consecutive days above average (and above freezing). Highs were 41° at National, 39° at Dulles, and 38° at BWI.
A low pressure area just now becoming organized in the central Rockies will deepen and move northeastward toward the Great Lakes, bringing with it the threat of some wintry precipitation in the Mid Atlantic region Sunday.
Tonight and Tomorrow
Clear, less windy, cold. Under clear skies and diminishing winds, lows tonight should be from the low 20s downtown to the mid and upper teens in 'burbland. Tomorrow will be mostly sunny and continued cold, less windy than today with highs 42-45°For the outlook through the rest of the weekend, including Sunday's potential wintry mix, scroll down to Camden's post below.
Tropical Topics
Winter may be still batting, but tropical season is just over 90 days away. Here at PM Update, we're getting in the mood by starting to read Ivor van Heerden's "The Storm", a scientist's on-the-scene report of the Katrina experience. From the tone of the introduction, it appears that he will be pulling no punches in his analysis of what went on.Meanwhile, yesterday the National Hurricane Center published their annual post mortem analysis of forecast accuracy for last year's storm season. The good news: Atlantic track forecast accuracy set new records in the range from 12-72 hr., beat each individual dynamical model, and only slightly trailed the consensus models. The bad news: Intensity forecasting continues to be a formidable problem. Intensity accuracy was close to the average of the last 5 years, but skill levels (improvement over average conditions, or climatology and persistence) were "down sharply."
Chart of hurricane track forecast accuracy in nautical miles at 24, 48, 72, 96, and 120 hr., years 1990-2006, from NHC
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Winter, What Remains Up Thy Sleeve?
Mixed precipitation possible on Sunday
A. Camden Walker @ 2:25 PM
*Winter Storm Watch in Effect Late Saturday Night Through Sunday Night*
Winter-hardened Washingtonians can certainly withstand today's "slight" breeze -- gusts to 40mph and possibly higher -- and our next few days of Winter's resurgence. Right? Hang in there! Winter will try to whip you around, knock out your power, and perhaps even scare you with a bit of frozen precipitation on Sunday morning. But Winter is weak, I say! And the sun angle ever-stronger ... (ok ok, yes, the Snow Lover's Crystal Ball has returned below).
Still Windy. Today's high temperatures near 40 could feel more like the 20s at times. Gusts to 50mph are possible, as ever-drier air moves in during the day today behind yesterday's storm system that is now strengthening on its way out to sea, beyond Cape Cod. My chapped lips say enough enough is enough already! Anyway, the skies will be mostly sunny and precipitation chances are zero.
Tonight, will be clear, breezy, and cold. Lows will range from 18-23° (Dulles-DCA). I hope you didn't lose track of your heavy coat and scarf with our refreshingly average temperatures during the last few days.
Clear & Calming. It won't be a super-serene day, but it will be clear with slackening breezes -- especially near sunset. High temperatures will be in the mid-40s. Clouds move in quickly after dark ... what's in store?
Wet & ... Wintry? Overcast skies ahead of an approaching storm will shroud the region well before dawn; however, not in time to keep temperatures from dropping below freezing. Morning lows will range from 25-30°. There is a 25% chance that some precipitation could begin before sunrise, which would be the most problematic time in terms of sub-freezing temps. But highs should eventually bolt upwards to near 40° with moderate amounts of rain possible during the afternoon. Let's discuss the potential wintry onset of this event ...
Snow Lover's Crystal Ball 
Next Chance of Accumulating Snow: Sunday AM
Probability: 30%
Potential Impact:
Commentary: Sunday morning just before dawn through late morning could prove interesting. Confidence is pretty low with this forecast, but the potential does exist for a few hours of wintry precipitation, beginning first as snow, then transitioning quickly to sleet, and finally some freezing rain. Surface temperatures should warm above freezing by late morning (around 10 or 11am, it appears at this point) after which rain could become moderate in intensity. As usual, the northern and western suburbs will probably be the last to surpass the freezing mark.
The ever-important psychological impact could be moderate during the early morning -- you know what happens when DC area drivers see a flake: nerves can quickly get frazzled. The overall impact, especially considering the weekend morning timing, is likely to be a lot less severe than the last storm. Accumlations of snow and ice are not likely to be substantial, especially given the predicted 36°-40° afternoon highs.
Winter-hardened Washingtonians can certainly withstand today's "slight" breeze -- gusts to 40mph and possibly higher -- and our next few days of Winter's resurgence. Right? Hang in there! Winter will try to whip you around, knock out your power, and perhaps even scare you with a bit of frozen precipitation on Sunday morning. But Winter is weak, I say! And the sun angle ever-stronger ... (ok ok, yes, the Snow Lover's Crystal Ball has returned below).
Today
Still Windy. Today's high temperatures near 40 could feel more like the 20s at times. Gusts to 50mph are possible, as ever-drier air moves in during the day today behind yesterday's storm system that is now strengthening on its way out to sea, beyond Cape Cod. My chapped lips say enough enough is enough already! Anyway, the skies will be mostly sunny and precipitation chances are zero.A slightly shrouded winter afternoon sky at Constitution Ave. and 17th St. NW, near The National Mall. By CapitalWeather.com's A. Camden Walker.
Saturday
Clear & Calming. It won't be a super-serene day, but it will be clear with slackening breezes -- especially near sunset. High temperatures will be in the mid-40s. Clouds move in quickly after dark ... what's in store?Wet & ... Wintry? Overcast skies ahead of an approaching storm will shroud the region well before dawn; however, not in time to keep temperatures from dropping below freezing. Morning lows will range from 25-30°. There is a 25% chance that some precipitation could begin before sunrise, which would be the most problematic time in terms of sub-freezing temps. But highs should eventually bolt upwards to near 40° with moderate amounts of rain possible during the afternoon. Let's discuss the potential wintry onset of this event ...Next Chance of Accumulating Snow: Sunday AM
Probability: 30%
Potential Impact:
Commentary: Sunday morning just before dawn through late morning could prove interesting. Confidence is pretty low with this forecast, but the potential does exist for a few hours of wintry precipitation, beginning first as snow, then transitioning quickly to sleet, and finally some freezing rain. Surface temperatures should warm above freezing by late morning (around 10 or 11am, it appears at this point) after which rain could become moderate in intensity. As usual, the northern and western suburbs will probably be the last to surpass the freezing mark.
The ever-important psychological impact could be moderate during the early morning -- you know what happens when DC area drivers see a flake: nerves can quickly get frazzled. The overall impact, especially considering the weekend morning timing, is likely to be a lot less severe than the last storm. Accumlations of snow and ice are not likely to be substantial, especially given the predicted 36°-40° afternoon highs.
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Thursday, February 22, 2007
Spring Pops Up; Winter Attempting to Rally
Steve Scolnik @ 5:10 PM
*Wind Advisory in Effect Through 10am Friday*
Now
Windy, turning colder. Some light showers (0.01") and even the sound of thunder in some places ushered in winds gusting over 40 mph at times as a cold front south of an energetic clipper system moved briskly eastward through the Washington metro area today. Temperatures, however, again exceeded expectations, popping up to the nearly spring-like upper 50s before they began to drop around mid afternoon. Highs were 59° at National, 56° at Dulles, 55° at BWI. To the south, Charlottesville and Richmond were both in the low 60s. Winter will be attempting to stage a comeback in the next couple of days as below-average temperatures return along with a marginal possibility of some more winter-like precipitation on Sunday.
Surface weather map at 1pm today from HPC/NCEP/NWS
Tonight and Tomorrow
Clearing, windy, colder. Lows tonight under clearing skies will be in the upper 20s to near 30°. Tomorrow will be mostly sunny and breezy with highs only in the low 40s. For the outlook through the weekend and beyond with Larson's Long-Range, scroll down to Josh's post below.
Winter Thunder
The 30-year climatological average is 1 February thunderstorm every 5 years in Washington, but thunder has now been observed in 2 consecutive Februarys and in 3 out of the last 5. The previous occurrence to last year was in 2003.
Mediaorology: Channel 4 Sweeps V-Day Storm Coverage
Yesterday's WaTi business section had an article, "TV news makes hay out of snow" about the local news ratings during the Valentine's Day storm and the implications of the weather coverage for the all-important February "sweeps" period. The corrected rankings in today's dcrtv blog show WRC-4 in first place for all 3 time slots (6am, 5pm, 11pm), followed by WJLA-7 at 6am and 5pm; WTTG-5 was second at 11pm. WUSA-9 was last at 6am and 11pm and 3rd at 5pm. WRC's score was at least 50% above the last-place station in each set of ratings; it was over 4 times the last-place WUSA-9 at 11pm.CapitalWeather.com chart from Washington Times data via dcrtv.com, photo © Kevin Ambrose
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Active Pattern Shaping Up
Josh Larson @ 8:13 AM
*Wind Advisory in Effect Through 10am Friday*
The weather over the coming week will be changeable and rather unsettled, with high temperatures bouncing from the upper 30s to the low 50s, in addition to chances for both liquid as well as frozen precipitation. Look out, especially, for windy conditions later today into tonight.
Mostly cloudy + windy. Expect more clouds than sun today with a slight chance of a passing shower or thundershower. Highs will be near 50, with winds picking up as the day wears on (from 10-30mph). Tonight will feature strong northwestly winds (20-40mph+) with overnight lows near 30.
Much colder & blustery. Behind today's cold front we'll see partly sunny skies and blustery conditions on Friday with much cooler highs struggling to get out of the low 40s; NW winds 15-25mph will make it feel 10 degrees colder. Clear and cold Friday night with lows ranging from 20-25.
Saturday: Sunny but cool. Expect mostly sunny skies on Saturday with light winds and highs in the mid 40s in most spots; overnight lows will dip down to the upper 20s Saturday night
Sunday: Icy mess?? An area of low pressure will bring precipitation to our region from the early morning hours on. It is possible, due to a layer of cold air close to surface, that we may see several hours (or more) of sleet 0R freezing rain (especially N&W of town) before precipitation changes to plain rain in the afternoon hours. Expect highs only in the upper 30s. Scattered showers continue Sunday night, with lows nearly steady in the mid to upper 30s.
Pattern Overview
A pretty active (and at times amplified) jet stream pattern will allow for multiple waves of low pressure to push across the nation over the next week to ten days; meanwhile, a new shot of cold air building in later today will bring temperatures back to below normal levels for tomorrow through the first half of next week. Despite significant warming aloft, cold air near the surface may be difficult to dislodge (as we saw with our sleet storm earlier in the month), so frozen precipitation on Sunday is certainly a possibility. The next area of low pressure enters the scene late Tuesday though rain is the favored precipitation type at this point. Temperatures may bounce back up above 50 again by Thursday of next week.
Pictured above: the GFS shows multiple "short-waves" pushing across the center of the nation over the next week, allowing for a rather active pattern with changeable weather for our area; courtesy Unisys.com
Next week's forecast
Forecast highs/lows: 47/32 (normal = 51/33)
Forecast precip: Near normal.
We'll look for skies becoming partly sunny on Monday with high temperatures in the low to mid 40s and lows near 30. Increasing clouds are likely on Tuesday, with showers of rain or wet snow possible late in the day into overnight period; expect highs in the low to mid 40s with overnight lows in the low to mid 30s. Wednesday will feature a return to partly sunny skies, with highs in the upper 40s and lows around 32. Thursday and Friday look to feature partly sunny and generally dry weather with highs quite close to the climatological average of 50/33.
The weather over the coming week will be changeable and rather unsettled, with high temperatures bouncing from the upper 30s to the low 50s, in addition to chances for both liquid as well as frozen precipitation. Look out, especially, for windy conditions later today into tonight.
Today
Mostly cloudy + windy. Expect more clouds than sun today with a slight chance of a passing shower or thundershower. Highs will be near 50, with winds picking up as the day wears on (from 10-30mph). Tonight will feature strong northwestly winds (20-40mph+) with overnight lows near 30.Tomorrow
Much colder & blustery. Behind today's cold front we'll see partly sunny skies and blustery conditions on Friday with much cooler highs struggling to get out of the low 40s; NW winds 15-25mph will make it feel 10 degrees colder. Clear and cold Friday night with lows ranging from 20-25.Saturday: Sunny but cool. Expect mostly sunny skies on Saturday with light winds and highs in the mid 40s in most spots; overnight lows will dip down to the upper 20s Saturday night Sunday: Icy mess?? An area of low pressure will bring precipitation to our region from the early morning hours on. It is possible, due to a layer of cold air close to surface, that we may see several hours (or more) of sleet 0R freezing rain (especially N&W of town) before precipitation changes to plain rain in the afternoon hours. Expect highs only in the upper 30s. Scattered showers continue Sunday night, with lows nearly steady in the mid to upper 30s.LARSON'S LONG-RANGE
Pattern Overview
A pretty active (and at times amplified) jet stream pattern will allow for multiple waves of low pressure to push across the nation over the next week to ten days; meanwhile, a new shot of cold air building in later today will bring temperatures back to below normal levels for tomorrow through the first half of next week. Despite significant warming aloft, cold air near the surface may be difficult to dislodge (as we saw with our sleet storm earlier in the month), so frozen precipitation on Sunday is certainly a possibility. The next area of low pressure enters the scene late Tuesday though rain is the favored precipitation type at this point. Temperatures may bounce back up above 50 again by Thursday of next week.Pictured above: the GFS shows multiple "short-waves" pushing across the center of the nation over the next week, allowing for a rather active pattern with changeable weather for our area; courtesy Unisys.com
Next week's forecast
Forecast highs/lows: 47/32 (normal = 51/33)
Forecast precip: Near normal.
We'll look for skies becoming partly sunny on Monday with high temperatures in the low to mid 40s and lows near 30. Increasing clouds are likely on Tuesday, with showers of rain or wet snow possible late in the day into overnight period; expect highs in the low to mid 40s with overnight lows in the low to mid 30s. Wednesday will feature a return to partly sunny skies, with highs in the upper 40s and lows around 32. Thursday and Friday look to feature partly sunny and generally dry weather with highs quite close to the climatological average of 50/33.
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Wednesday, February 21, 2007
Winter Strikes Out
Steve Scolnik @ 4:55 PM
Now
Sunny, seasonably mild. There are still a few more innings to be played, but winter has struck out in the Washington metro area, at least for now. Despite a northerly breeze, mild Pacific air and strong sunshine pushed temperatures beyond the optimistic end of the forecast range by mid afternoon, reaching the mid 50s. Highs were 56° at National, 52° at Dulles and BWI. After 7 consecutive days with 1" or more of snow/ice on the ground, melting has reduced the depth to 0. The melting was helped by the 0.25" of showers which fell last night. Freezing temperatures throughout the country have retreated to near the Canadian border.Temperature chart at 3pm today from Unisys
Tonight and Tomorrow
Partly cloudy, mild. Lows tonight will be in the mid to upper 30s under partly cloudy skies, with some low 30s in the cooler 'burblands. Tomorrow will be variably cloudy with highs near 50°, but becoming breezy and colder late in the day. There is a 30% chance of showers in the late afternoon or evening.For the outlook through the rest of the week and the weekend, scroll down to Dan's post below.
Climate Corner
Today's WaPo reports that the Maryland House of Delegates has approved with a wide bipartisan 122-16 margin a bill to regulate auto CO2 emissions. Following inaction at the federal level, 10 other states have already enacted regulations based on those established in California. Senate approval is expected, and Gov. O'Malley has promised to sign the bill, which requires new vehicles sold or registered in the state to have an average fuel economy of 43 miles per gallon by model year 2011.
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A Welcome Warmup
Dan Stillman @ 8:50 AM
While yesterday's warmup into the mid 40s to near 50 was tempered by overcast skies, today's slightly higher temperatures will be enhanced by sunshine. We aren't likely to see the 60s or 70s that we saw during parts of December and January, but highs in the mid 40s to mid 50s through the weekend and beyond will feel a lot better than our recent string of 20s and 30s.Pictured: Warmer temperatures over the next several days should melt away snow and ice, such as that found on Saturday around the Three Servicemen Statue at the Vietnam Veterans Memorial. By CapitalWeather.com photographer Kevin Ambrose.
Today
Aiming for 50. A pleasant day on tap with partly to mostly sunny skies and highs in the low 50s. Tonight, partly cloudy with calm winds. Lows in the mid-to-upper 30s in town, low-to-mid 30s in the burbs.Tomorrow
Continued mild, Windy PM. A "clipper" low-pressure system passing to our north will mean partly cloudy skies and a chance of a sprinkle. Temperatures should climb once again to highs in the low 50s, but the most memorable feature of the day may be gusty afternoon and evening winds behind the clipper. Clearing, windy and colder overnight with lows 25-30.Windy, cooler. A brief blip in our overall warming trend, Friday will feature windy and cooler conditions. Despite lots of sunshine, it looks like highs will top out only in the low-to-mid 40s. Overnight, clear with slowly diminishing winds. Lows in the mid 20s in town, low 20s in the burbs.The Weekend
Sunny Saturday ... Stormy Sunday? Saturday is shaping up to be a great start to the weekend, with high pressure providing mostly sunny skies and highs in the upper 40s to near 50. Saturday night may bring increasing clouds, especially toward morning, with lows in the low-to-mid 30s in town, upper 20s in the burbs. Sunday, a storm system approaching from the west is likely to bring a lot of clouds and some rain to the area as highs reach the mid-to-upper 40s.Downside to Warmup
The arrival of warmer temperatures isn't all good news. In fact, it's the perfect recipe for potholes, which form as water from melting snow and ice seeps into roads, freezes and expands. Meanwhile, the warmer weather likely means that one Washington-area resident will no longer be able to skate by with an easy commute.
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Tuesday, February 20, 2007
Spring Training
Steve Scolnik @ 5:10 PM
Now
Mostly cloudy, seasonably cool. It's not quite spring-like, but except for a slight dip around noon, temperatures have been steadily rising since 8pm last night to more seasonable levels in the Washington metro area. Persistent clouds and a slowly melting ice pack kept readings in the immediate area to the mid and upper 40s, but sunnier locations as close as Fredericksburg exceeded 60°, and the 60s were common southward and eastward through the rest of Virginia. Today's high of 47°, with the midnight low of 37°, makes this the first day this month with above-average temperatures.The nearest precipitation is an area of showers in the Ohio Valley. Some of these showers ahead of a weak cold front should arrive overnight, to be followed by drier and seasonably mild conditions tomorrow.
Tonight and Tomorrow
Scattered showers, followed by clearing and seasonable. There is a 60% chance of rain showers overnight with lows in the upper 30s to around 40°. Clouds will decrease tomorow with highs 48-52°. For the outlook through the rest of the week, scroll down to Jason's post below.
Climate Corner
The board of the AAAS, the world's largest general science organization, released a statement on climate change on Sunday at the association's annual meeting in San Francisco. The statement, the first on global warming by the AAAS, was featured in an article, "Scientist Group Warns of Warming 'Threat'", on the back page of the WaPo A-section yesterday.
Also at the annual meeting, AAAS President John P. Holdren strongly urged scientists and engineers to become personally involved in working to find solutions to the challenges posed by "poverty, climate change and nuclear proliferation." His call to "tithe" 10% of their time "to working to increase the benefits of science and technology for the human condition and to decrease the liabilities" was received with a standing ovation.
Mediarology
Dave Statter's WUSA-TV report of vehicles spinning out of control on untreated Lee Highway in Rosslyn Sunday night was featured prominently and repeatedly on the Weather Channel's Evening Edition last night.
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Let the Melting Begin
Matt Ross @ 1:00 AM
After averaging more than 10 degrees below normal for the first two thirds of February, we are finally going to see a return to more normal temperatures over the next several days.
Cloudy, Warmer. Today will be partly to mostly cloudy and mild with afternoon highs near normal around 50 degrees. There is a 40% chance of some light rain developing later in the day. If we reach 50 degrees, it will be the 1st time since January 27th.
Showers, Breezy. There is a 70% chance of some light rain overnight as temperatures only drop to the mid 30s. The rain may mix with some wet snow in the far north and west suburbs, but with little or no accumulation. Wednesday will be partly sunny and breezy with highs again reaching the 50 degree mark. See Jason's forecast for the rest of the week and weekend.
The Big Chair in Anacostia this weekend, courtesy of CapitalWeather.com Photographer, Kevin Ambrose.
The 1st 19 days of February have averaged 26.52 degrees, or almost 11 degrees below normal. We have only hit the 40s once the entire month, and only experienced a low temperature in the 30s one time as well, while hitting the teens 11 out of the 19 days. Yesterday makes 22 straight days with an average temperature below normal. While the last 9 days of the month will average closer to normal, we will still finish the month well below normal and make a big dent in the positive departures of December and January. February is a lock to be the coldest February in DC since 1979. Here are a few more facts about the rest of February:
In order to become the coldest Feb in history at National Airport(DCA) since record keeping began there in 1941, the next 9 days must average -8.17 or colder.
In order to become the 2nd coldest February in history at DCA, the next 9 days must average -0.08 or colder.
In order for December, January and February to average one degree above average or colder at DCA, the next 9 days must average -1.11 or colder.
In order for February 2007 to make the top 10 coldest months on record at DCA, the next 9 days must average -0.40 or colder.
In order for Feb 2007 to make the top 10 coldest February's on record since 1871, the next 9 days must average -3.63 or colder.
Pictured Above Right: Mt. Pleasant on Sunday during a snowshower, courtesy of CapitalWeather.com Photographer, Ian Livingston.
Today
Cloudy, Warmer. Today will be partly to mostly cloudy and mild with afternoon highs near normal around 50 degrees. There is a 40% chance of some light rain developing later in the day. If we reach 50 degrees, it will be the 1st time since January 27th.
Tonight and Tomorrow
Showers, Breezy. There is a 70% chance of some light rain overnight as temperatures only drop to the mid 30s. The rain may mix with some wet snow in the far north and west suburbs, but with little or no accumulation. Wednesday will be partly sunny and breezy with highs again reaching the 50 degree mark. See Jason's forecast for the rest of the week and weekend.
The Big Chair in Anacostia this weekend, courtesy of CapitalWeather.com Photographer, Kevin Ambrose.
Some Notes About Cold February
The 1st 19 days of February have averaged 26.52 degrees, or almost 11 degrees below normal. We have only hit the 40s once the entire month, and only experienced a low temperature in the 30s one time as well, while hitting the teens 11 out of the 19 days. Yesterday makes 22 straight days with an average temperature below normal. While the last 9 days of the month will average closer to normal, we will still finish the month well below normal and make a big dent in the positive departures of December and January. February is a lock to be the coldest February in DC since 1979. Here are a few more facts about the rest of February:
In order to become the coldest Feb in history at National Airport(DCA) since record keeping began there in 1941, the next 9 days must average -8.17 or colder.
In order to become the 2nd coldest February in history at DCA, the next 9 days must average -0.08 or colder.
In order for December, January and February to average one degree above average or colder at DCA, the next 9 days must average -1.11 or colder.
In order for February 2007 to make the top 10 coldest months on record at DCA, the next 9 days must average -0.40 or colder.
In order for Feb 2007 to make the top 10 coldest February's on record since 1871, the next 9 days must average -3.63 or colder.
Pictured Above Right: Mt. Pleasant on Sunday during a snowshower, courtesy of CapitalWeather.com Photographer, Ian Livingston.
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Monday, February 19, 2007
The Week Ahead: Winter Loosens Its Grip
Jason Samenow @ 10:30 AM
After one of the coldest starts to February on record along with episodes of ice and snow, winter will relax this week. The result will be a return to mild temperatures and melting snow/ice cover.
Mostly sunny, chilly. The cold pattern will grip the region for one final day. After starting off in the teens, temperatures should warm into the upper 30s by late this afternoon. Overnight, it will be clear and not as cold with lows 23-28 (suburbs-city).
Coldest Day: Today, High 38.
Warmest Day: Sunday, High 55.
Dry Days: Today, Thursday through Saturday.
Precipitation Chances: Tuesday night, Wednesday morning, late Sunday.
The Week's Wild Cards: How much rain will fall overnight Tuesday? How warm will it get Sunday and will it rain late in the day?
Climatological Average High/Low: 48-50/30-32
Pictured: Partly cloudy skies at Great Falls yesterday morning. By CapitalWeather.com photographer Kevin Ambrose.
Increasing clouds, milder. Chance of rain at night. As the cold air mass lifts away, much more seasonable air will take its place. Expect increasing high clouds and relatively mild temperatures, with highs 45-50. Overnight, a low will form along a weak cold front passing through the area, with a 50% chance of rain showers (possibly mixed with snow towards the mountains) with lows 33-37 (suburbs-city).
Gradual clearing, not cold. Behind Tuesday night's front, weak high pressure will gradually build into the area. The cold front won't pack much punch, with highs similar to the previous day -- around 45-50. Overnight, expect clear skies with lows 25-30 (suburbs-city)
Mostly sunny, mild. Weak southwesterly flow from high pressure to the south will result in a relatively nice day. Look for mostly sunny skies with highs in the low 50s. Overnight, a few clouds are likely as a clipper passes by to the north, with lows 28-33 (suburbs-city)
Partly sunny, a little cooler. Behind Thursday night's clipper, somewhat cooler air will move in as the flow becomes northerly. There should be more sun than clouds with highs in the mid 40s. Overnight, expect mostly clear skies, with lows 25-30 (suburbs-city).
Partly sunny, turning warmer. As low pressure begins developing in the Great Plains, we'll remain under the influence of (cool) high pressure to the north on Saturday. Expect a partly to mostly sunny day, with highs near 50. By Sunday, a warm front will approach as the low heads towards the Great Lakes. Winds will likely shift to more southerly resulting a mild day with a slight chance of showers late as the warm front nears. Highs will be probably be in the 50s.
Yesterday's brief bursts of heavy snow and strong winds were caused by an energetic wave in the atmosphere crashing down on us. The instability it generated helped spawn the intense snow squalls which resulted in brief bursts of heavy snow (reducing visibility to less than 1/4 mile at times), gusty winds and falling temperatures (5-8 degrees in minutes). The dynamics involved were not unlike those associated with a spring thunderstorm.
Accumulations ranged from a dusting to half an inch -- although there were unconfirmed reports of over an inch around Silver Spring. Snowfall rates were as high as 3" an hour but were not sustained more than 10 minutes or so in most spots. See this video of the snow squalls in McLean shot by CapitalWeather.com visitor Ned Burchfiel.
Pictured: Heavy snow falls on cars on 16th street (about 150ft away) from Park Rd in Mt Pleasant in Washington, DC early yesterday evening. By CapitalWeather.com photographer Ian Livingston.
Today
Mostly sunny, chilly. The cold pattern will grip the region for one final day. After starting off in the teens, temperatures should warm into the upper 30s by late this afternoon. Overnight, it will be clear and not as cold with lows 23-28 (suburbs-city).The Upcoming Week at a Glance
Coldest Day: Today, High 38.Warmest Day: Sunday, High 55.
Dry Days: Today, Thursday through Saturday.
Precipitation Chances: Tuesday night, Wednesday morning, late Sunday.
The Week's Wild Cards: How much rain will fall overnight Tuesday? How warm will it get Sunday and will it rain late in the day?
Climatological Average High/Low: 48-50/30-32
Pictured: Partly cloudy skies at Great Falls yesterday morning. By CapitalWeather.com photographer Kevin Ambrose.
Increasing clouds, milder. Chance of rain at night. As the cold air mass lifts away, much more seasonable air will take its place. Expect increasing high clouds and relatively mild temperatures, with highs 45-50. Overnight, a low will form along a weak cold front passing through the area, with a 50% chance of rain showers (possibly mixed with snow towards the mountains) with lows 33-37 (suburbs-city).Gradual clearing, not cold. Behind Tuesday night's front, weak high pressure will gradually build into the area. The cold front won't pack much punch, with highs similar to the previous day -- around 45-50. Overnight, expect clear skies with lows 25-30 (suburbs-city) Mostly sunny, mild. Weak southwesterly flow from high pressure to the south will result in a relatively nice day. Look for mostly sunny skies with highs in the low 50s. Overnight, a few clouds are likely as a clipper passes by to the north, with lows 28-33 (suburbs-city)Friday
Partly sunny, a little cooler. Behind Thursday night's clipper, somewhat cooler air will move in as the flow becomes northerly. There should be more sun than clouds with highs in the mid 40s. Overnight, expect mostly clear skies, with lows 25-30 (suburbs-city).The weekend
Partly sunny, turning warmer. As low pressure begins developing in the Great Plains, we'll remain under the influence of (cool) high pressure to the north on Saturday. Expect a partly to mostly sunny day, with highs near 50. By Sunday, a warm front will approach as the low heads towards the Great Lakes. Winds will likely shift to more southerly resulting a mild day with a slight chance of showers late as the warm front nears. Highs will be probably be in the 50s.Yesterday's Snow Squalls
Yesterday's brief bursts of heavy snow and strong winds were caused by an energetic wave in the atmosphere crashing down on us. The instability it generated helped spawn the intense snow squalls which resulted in brief bursts of heavy snow (reducing visibility to less than 1/4 mile at times), gusty winds and falling temperatures (5-8 degrees in minutes). The dynamics involved were not unlike those associated with a spring thunderstorm. Accumulations ranged from a dusting to half an inch -- although there were unconfirmed reports of over an inch around Silver Spring. Snowfall rates were as high as 3" an hour but were not sustained more than 10 minutes or so in most spots. See this video of the snow squalls in McLean shot by CapitalWeather.com visitor Ned Burchfiel.
Pictured: Heavy snow falls on cars on 16th street (about 150ft away) from Park Rd in Mt Pleasant in Washington, DC early yesterday evening. By CapitalWeather.com photographer Ian Livingston.
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