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* Winter Storm Warning today for entire region | Wind Chill Advisory tonight thru Wed. noon | Local closings | The Grid (images from around town) | Reader photo compilationLatest snow amounts from NWS *

Basic information (see more details at bottom of this post)

  • How much snow are we forecasting? 4-7″ for immediate metro area, 6-10″ for northern suburbs, 2-5″ south of Fredericksburg (see map at bottom of post)
  • When will it be the worst? Late afternoon and early evening, when strong winds and very cold temperatures accompany snow, possible hazardous travel
  • When will it end? 7-10 p.m., from west to east, but strong winds and frigid temperatures follow storm.

3:04 p.m. update: We have a new update posted. Please click on this link for the latest information: Wind-driven snow, falling temperatures as storm hits its stride (LIVE UPDATES)

2:40 p.m. update: Radar shows light to moderate snow across the region, with a heavier band parked over Montgomery County. Snow tends lighter the farther south you go. Winds are picking up out there, gusting between 20 and 30 mph. These gusts may increase to 30 to 40 mph this evening, causing restricted visibility and blowing around the snow. Here are a few recent pics from Twitter:

2:30 p.m. update: Here’s a video update I did out in the snow downtown in the last hour…

Capital Weather Gang's Jason Samenow says the snow falling on the Washington area will continue to increase in intensity this afternoon, followed by a drop in temperatures. (Pamela Kirkland/The Washington Post)

2:10 p.m. update: Snow is falling at a decent clip and accumulating north of I-66, including over much of the District. However, south of I-66 in Virginia, you get into possible “bust” territory, and the snow decreases in intensity. This may well be the pattern for the next several hours. Yes, the snow may expand some to the south, but if you live in southern Fauquier, Stafford and southern Prince William counties, or to the south, your chances of getting more than a couple inches of snow aren’t great.

Here’s a round-up of snowfall totals so far from readers: Frederick co, Md 4-6″; Montgomery county 2-4″, Fairfax County 1-3″, the District 1-2″, Alexandria 1-2″, Arlington around 2″, Loudoun County 2-6″, Prince William County: Around 1″

1:35 p.m. update: Radar shows steady snow over the area, generally falling at a half inch per hour rate. Temperatures are well below freezing, mostly in the mid-20s. There’s some potential for the snow to increase in intensity as the afternoon progresses as low pressure strengthens off the coast. From Fredericksburg and to the southwest, yes, this may turn into a bit of a bust. And, given the slow start, it may be a challenge for downtown D.C. (and Reagan National) to get to 4″, but the forecast is more or less on track. Roads are getting slick now even in the city and the height of this storm is likely still to come.

Below we see the steep drop in pressures off the East Coast over the last three hours, a sign the storm is intensifying.


Pressure drop over last three hours (Unisys Weather)

1:05 p.m. update: The National Weather Service’s High Resolution Rapid Refresh (HRRR) model shows continued periods of moderate snow over the region through 6 p.m., before it begins to taper. For the immediate metro area, we have quite a few more hours of snow to go. Notice, however, there is a bit of a cutoff not far to the south and west in central Virginia.


HRRR model simulation of snow through 6 p.m. in D.C. area (WeatherBell.com)

12:38 p.m. update:

Here’s a video I shot in the snow about an hour ago…

Speaking from the roof of The Washington Post, Jason Samenow says some D.C. suburbs can expect up to 10 inches of snow Tuesday. (Pamela Kirkland/The Washington Post)

12:35 p.m. update: Temperatures have really fallen off and are now into the 20s everywhere. They will continue to gradually fall. Treated roads are mostly clear of snow around town according to reports, but side roads are gradually becoming snow-covered. When snow picks up in intensity, even treated roads could become slick, especially later this afternoon as it gets darker.


Noon temps

 

 

12:15: As snow falls steadily across the area, some impressive totals are coming in from the west. Frederick has 4 inches, Gaithersburg 2 inches, Damascus 3 inches. and about 4 inches out towards Lovettsville (Loudoun Co.) and Winchester.

 

11:36 a.m. update: As a new coastal storm starts to develop, we’re seeing signs of a heavy snow band setting up right along the I-95 corridor. Snow is beginning to accumulate on roads even inside the Beltway, so please use caution traveling. The National Weather Service Storm Prediction Center sees the potential for snowfall rates of 1-2 inches per hour or so in this zone well into the afternoon:

LATEST RADAR LOOP SHOWS THE HEAVIEST SNOWFALL NOW OCCURRING FROM THE ERN HALF OF MD AND ADJACENT NRN VA NEWD TO SRN NJ…WITH AN INCREASE IN COVERAGE OF HEAVIER PRECIPITATION OCCURRING OVER THE LAST HOUR. EXPECT A CONTINUED EXPANSION — AND VERY SLOW ENEWD SHIFT — OF THE ZONE OF HEAVIEST SNOWFALL…AS THE AFOREMENTIONED AREA OF FOCUSED ASCENT INTENSIFIES OVER THE NEXT SEVERAL HOURS.


(National Weather Service Storm Prediction Center)

 

11:10 a.m. update: All of the nervous Nellies concerned that temperatures would be too warm for snow will be relieved to know that Reagan National Airport dropped to 32 as of 11 a.m. If your location is not below freezing now, you will be by noon and temperatures may not rise above freezing again until Saturday.

Radar shows a band of moderate snow along and just west of I-95 drifting east towards the District and eventually into the eastern suburbs.

Some of the worst conditions continue to be in Montgomery, Loudoun and Frederick county, where generally 1-3 inches have fallen, with roads becoming slick.

 

 

10:40 a.m. update: Radar is really starting to fill in and snow is falling in much of the region, though it’s just getting started in our eastern suburbs. Amounts are mounting fast in D.C.’s colder western and northern suburbs. We’re getting reports of 2 inches already in northern and western Montgomery County and up to 3 inches around Frederick, Md. In the District, where temperatures are now falling to near freezing, a dusting on grassy areas and elevated surfaces is beginning. Radar shows a moderate to heavy band of snow from western Fairfax County through central Montgomery and Howard counties drifting east towards the District – which will help accumulation get going inside the Beltway.

 

 

10:04 a.m. update: Light snow has now moved into most of the District and Fairfax County. The snow may take an hour or so (possibly even longer in urban areas) to begin accumulating as temperatures drop to freezing and eventually below freezing.

Moderate to heavy snow has developed in western Montgomery, Loudoun and Frederick counties, with 1-2 inches already in some locations.

Snow should finally reach our south and east suburbs by around 11-11:30 a.m.

 

LINK: Detailed forecast through the weekend

Overview: Snow has developed in the region and should gradually increase in coverage and intensity during the day. We expect the heaviest snow to fall in D.C.’s northern suburbs where 6-10 inches of snow is possible before the storm ends. Closer to town, 4-7 inches is most likely.


Capital Weather Gang snowfall forecast issued at 6:30 a.m. Tuesday

Through this morning, the conditions will be worst in D.C’s north and northwest suburbs. During the afternoon, greater coverage of accumulating snow will result in more widespread slick roads as temperatures fall through the 20s. The worst travel time will likely be between late afternoon and early this evening, when a combination of wind and snow may produce low visibilities and hazardous roads. We expect snow to taper off from west to east between around 7 and 10 p.m. The snow will be followed by strong winds and bitter cold temperatures. Low temperatures overnight will drop into the single digits with wind chills from -5 to -15.

GALLERY: The worst storms, etc. to hit Washington in the past decade