Overview: Winter Storm warnings have been extended east to include D.C. and Baltimore, as well as Prince George’s and Anne Arundel counties. Ice accumulation of around 0.25″ is now expected by the National Weather Service in these areas. Further west, where warnings were already up, even higher totals are possible overnight. Expect at least a couple rounds of at least moderate freezing rain, perhaps mixing with some sleet, through the night. Between these rounds, lighter showers and freezing drizzle may persist as temperatures remain near or below freezing.
10:50 p.m. Update: We have a real smorgasboard of conditions being reported around the area. In some places, ice is accumulating and creating a glaze on everything. In other places, the rain has been heavy enough that much of it is running off. In Mt. Pleasant, D.C., ice is accumulating on trees and power lines, even as the latest temperature report from National Airport is up to 34F. Power outages are spiking a bit, especially in Northern Virginia. Bottom line, it’s hard to say exactly what conditions will be like in the morning, but generally speaking we continue to expect the most problems in the north and west suburbs, with more manageable roads from D.C. to the south and east (even there, many side roads may still be icy or slushy in the morning). We’ll be back at 5 a.m., but please continue to let us know the conditions near you in the comments section at the bottom of this post.
10:45 p.m. Update: Snowy pictures from today’s snowy football games! … check it out.
10:25 p.m. Update: As we mentioned earlier, we are watching the potential for another storm on Tuesday. Believe it or not, this evening’s NAM model (which admittedly isn’t always the most reliable of models) is simulating several inches of snow Tuesday morning into the afternoon. And its not alone, with other models (including the GFS and Canadian) indicating the potential for significant snow as well. The typically more reliable European model showed little to no snow in this morning’s run (its next run doesn’t come out until the overnight). We will be looking closely at the models and hope to have a grasp on Tuesday’s snow potential by midday Monday.
10 p.m. Update: We talked in our 8:10 p.m. Update below of the chance that heavy precipitation could actually bring warmer air down to the surface. We are seeing some evidence of that downstream to the southwest, around Culpeper, Orange and Charlottesville, where temperatures climbed several degrees with the batch of moderate to heavy freezing rain and sleet now over the D.C. area. Obviously any warming at the surface would be a good thing, and would be most helpful for areas from near I-95/D.C. and to the east where temperatures are already at or not too far below freezing.
9:30 PM: Temps have risen dramatically in the last hour. Most places are at or close to 32°. More rain=fewer icy rds! pic.twitter.com/lQfYuFOnj7
— WCAV-TV Weather (@CBS19Weather) December 9, 2013
9:45 p.m. Update: We’ve got thunder and lightning! Several reports of such have come in from areas southwest of D.C. where heavy precipitation has been moving through…
— Capital Weather Gang (@capitalweather) December 9, 2013
And here’s proof from a local lightning network (purple dots south-southeast of Manassas indicate lightning):
9:25 p.m. Update: The next batch of precipitation is rapidly approaching the southwest branch of the Beltway and should be into D.C. proper within 20 minutes. We think this will be mostly freezing rain given the warmth of the air aloft, but could mix with sleet as well. This will only further exacerbate the poor road conditions in the north and west suburbs where temperatures are stuck in the upper 20s. Perhaps not quite as impactful for D.C./I-95 to the east, where temperatures are a bit closer to the freezing mark (The 9 a.m. temperature at Regan National was 32F). Regardless, this is not a night to be out.
8:40 p.m. update: Based on reports from Facebook and Twitter, roads around the region currently range from “horrible” (mainly side roads) to “passable but slow” (mainly large thoroughfares). Sidewalks are also a problem in the District and surrounds. Plan for slow travel if you must be out. Again, it’s probably best to stay in at this point.
@capitalweather roads north of Baltimore heading towards DC are wet, but traffic is moving.
— Katie McBreen (@KWMcBreen) December 9, 2013
@capitalweather 29 and NH in MoCo are wet and slushy but not too bad. Side streets dicier but mostly passable w care. As of 8pm.
— Megan in MD (@MeganinMD) December 9, 2013
@capitalweather roads in and around Leesburg still covered except for major thoroughfares like Rt 7 and Rt 15. Those are slushy in places.
— megachris (@megachris) December 9, 2013
Walked out to get dinner around 4th & Mass NW and sidewalks much worse than expected. Ice glaze on tree branches already @capitalweather
— Richard Barnhill (@wolfpackwx) December 9, 2013
8:10 p.m. update: While the next batch of sleet and freezing rain is likely to add to the many ice problems across the area, and the power outage threat subsequently grows, we’ll need to watch and see if the heavier activity helps draw some warmer air down from above. The 7 p.m. observation from a weather balloon released near Dulles Airport shows temperatures rising above freezing just a few thousand feet off the ground. That air will continue to warm and lower, allowing precipitation to bring some of it to the surface. In places where temperatures are already near freezing, we may see them rise a bit above prior to morning. However, short term models tend to want to keep temps around 32 or lower in D.C. and even southeast.
Bad news more ZR coming Good news any moderate rain will bring warm air to surface and by AM temps mid 30s DC metro
— Bob Ryan (@BobRyanCCM) December 9, 2013
7:40 p.m. update: Temperatures are still sitting in the upper 20s and lower 30s most spots, even mid-20s over far northwest parts of the area. Just a few freezing rain showers and freezing mist are over the immediate region at this time, but icing continues to be a big issue for many. The next batch of precip is now into the Charlottesville area, headed our way in the next few hours. If you don’t need to be out, it’s best not to be. Even if you need to be you might want to reconsider. Here’s a radar simulation from the HRRR, a short range model, showing freezing rain picking up by 9 or 10 p.m.:
7:10 p.m. update: The U.S. Office of Personnel Management (check operating status) is monitoring the storm before making a final decision on tomorrow’s status for the federal government. We think this is still a “two dome” risk, so do your work homework!
FedCast: 2 capitol domes
(50/50 unscheduled leave policy and/or delay. Closing possible but not likely.)
We are monitoring the weather and we will have an update as soon as possible.
— OPM News (@USOPM) December 8, 2013
6:50 p.m. update: While we sit in this lull, it’s worth taking a quick look ahead toward our next winter weather threat. CWG winter weather expert Wes Junker says: “The next chance at wintry weather will be on Tuesday as weak surface low tracks along a front to our south. Right now it looks more like a light snow event with surface temperatures expected to be in the low-to-mid 30s. We’ll have a more in depth look tomorrow once the current event plays out.”
Models continue to have disagreements on this system, with some advertising an accumulating snow event and others showing just some lighter snow showers or even just clouds. The European model, usually among the best for forecasting storm systems, is currently on the lighter side, but it has trended “snowier” in recent runs. It does appear we’ll at least be threatened by the prospect of accumulating snow. Stay tuned…
6:15 p.m. update: A number of schools have already announced they are closing in western parts of the area. These include Frederick and Loudoun county schools, among others. Given the likelihood of prolonged ice through the night, this list seems likely to grow at least a bit. The main zone in which closures are most likely appears to be in a Fairfax to Montgomery counties line or north and west. Places south and east of there run a smaller yet not tiny risk.
Monday SchoolCast for points northwest of D.C. (Montgomery, Fairfax, Loudoun, Frederick, Fauquier): 3-4 apples
(Numerous schools closed or likely to close. Delays elsewhere.)
Monday SchoolCast for everyone else (D.C. schools, Prince George’s, Howard, Prince William, Anne Arundel and Calvert counties): 2 apples
(50/50 chance of a delay. Closing possible.)
5:50 p.m. update: A look at radar across the eastern U.S. shows the next wave in this multi-part winter storm approaching from the southwest. While it does so, temperatures remain in the upper 20s to lower 30s. Short range models continue to indicate a very slow warming process overnight, with most of the region likely to stay near or below freezing through around sunrise. Places south and east of I-95 may still get there sooner, but less likely than before.