PM Update: Light snow tonight, continued very cold Wednesday

* Winter weather advisories for D.C.’s south and east suburbs this evening through 6 a.m. Wednesday *

12:40 a.m. update: We’re going to sign off for the night (until 5 a.m.) but we think the forecast is in good shape. Expect snow for another 1-3 hours (ending first northwest, last east and southeast), with generally less than 0.5″ north of I-66 and west of the Beltway, up to 1″ around D.C. and south of town, up to 2″ east of I-95, and 2-4+” for Southern Maryland.


Radar & lightning: Latest D.C. area radar shows movement of precipitation and lightning strikes over past two hours. Refresh page to update. Click here or on image to enlarge. Or see radar bigger on our Weather Wall.

12:14 a.m. update: Snow continues to fall but I’m seeing some signs of the northwest fringe starting to collapse and shift eastward. So it may start tapering off in western suburbs between 12:30 and 1:30 a.m. and around town between 1:30 and 2:30 a.m. It will exit eastern areas last, probably by around 3:30 a.m..

11:45 p.m. update: Snow is falling at a light to moderate clip in most of the metro area and this may continue for another 2-3 hours. Given the powdery nature of the snow, this means quite a few folks could end up with 1″ or so (areas south of the Beltway favored) even west of I-95. East of I-95, a solid band of snow has developed and up to 2″ looks like a good bet there. In parts of southern Maryland, over 2″ has already fallen in spots and some 4″ totals are possible.

11:20 p.m. update: As light snow continues to fall, it’s worth noting how cold the temperatures are. At 11 p.m. it was 12 at Dulles and 16 at Reagan National. The snow is thus very powdery and can accumulate rather quickly even though it’s not falling intensely.

11:05 p.m. update: Around the metro region, about a dusting to half an inch of snow has accumulated so far, with the heaviest amount south and east of town. Radar shows some steadier snows southwest of town trying to stream northeast, so it’s certainly not out of the question some areas may achieve an inch or a little more – especially south and east of the Beltway. As you get north and northwest of the Beltway the light snow tapers off to flurries, so not much to talk about up there.

Temps are very cold – in the teens – so everything is sticking. We’ll continue update until at least midnight and possibly a bit longer.

10:05 p.m. update: A band that is producing light snow, at least in some places, has set up basically from I-66 south and from I-95 east including areas inside the Beltway. Many spots in the District and immediately south and east have already reported a dusting, with anything more than that confined to areas mainly south and east of the Beltway for now. This band may persist for a while, so watch for further whitening of the ground.

9:05 p.m. update: The main action so far continues to be in Southern Maryland, especially in St. Mary’s County and southern Calvert County, where snow has been moderate and accumulating. North and west of there across the immediate metro area has only seen flurries thus far, though radar indicates a better chance of seeing some light snow closer to D.C. over the next couple hours. This evening’s NAM model shows slightly less precipitation for the metro area than earlier runs, which suggests our map below (scroll down a bit) is still on track, and if anything a bit on the high side.

 

8:10 p.m. update: Snow’s still trying but not doing so well when it comes to moving into the area. Thus far the main snow worth noting is draped across St Mary’s and southern Calvert counties, where reports of light accumulation are coming in. Elsewhere, largely flurries if anything, and radar plus short-term modeling suggests it’s going to be a struggle, especially I-95 and west. Further to the southeast, the Storm Prediction Center is expecting heavy snow to fill in over coming hours across southeast Va. and southern Md. Here are a few recent reports across the broader region:

 

 

 

6:30 p.m. update: Snow has been reported at least as far north as Richmond, where it’s currently 16 degrees with light snow. Parts of southern Maryland as well as further south are also into snow. A batch of newer activity is growing on radar near and northeast of Charlottesville, but much of that may still not be hitting the ground. Snow is also trying to fill in east of I-95. This snow shield should continue to move north and northeast over the coming period, with some snow possibly reaching the ground in the next hour or so in spots. Any snow in the short term should focus on southern and eastern parts of the area, but perhaps up to about I-95.

From 5:05 p.m. … Temperatures struggled big time today, holding in the teens to near 20 in much of the metro region – more than 20 degrees below average. The big storm in the South tries to graze us overnight with some light snow on its way out into the Atlantic. For most of the metro region – with the exception of Southern Maryland – this looks to be a sweepable rather than shovelable snow. Some spots just see flurries.

Through Tonight: Cloudy and very cold with areas of light snow developing, especially south and east of the District. With temperatures in the teens, precipitation type is not in doubt and every flake that falls will stick. But, the arctic air mass over us is very dry and will tend to eat up some of the snow that tries to fall. The available moisture will increase some as you get closer to the Bay and especially Atlantic ocean. This is one of those rare cases where the most snow is expected southeast of D.C. rather than in northwest areas, which may just get flurries.

The most likely timing for the onset of snow is between 5 and 8 p.m. in southern Maryland, between 7 and 10 p.m. in Stafford, Prince William, Prince George’s, Charles, and Anne Arundel counties, and between 9 p.m. and midnight over the rest of the region.

Snow tapers off between 2 and 5 a.m., northwest to southeast.

In terms of accumulations, it’s possible locations north and west of Fairfax and Montgomery counties just see flurries – and even into the District if dry air wins out. There will be a sharp cutoff in accumulating snow, and it’s very difficult to nail that down. Inside the Beltway, a dusting of snow or so is most likely, but areas east of I-95 could get an inch or so, and even more into southern Maryland. The latest GFS model and short-term models don’t show a lot of precipitation, so – despite the NAM model suggesting 1-2″ in D.C. – we’re reluctant to increase our forecast totals in the map below (prepared earlier today).

Capital Weather Gang snowfall forecast Tuesday night, issued 11:58 a.m. Tuesday

Capital Weather Gang snowfall forecast Tuesday night, issued 11:58 a.m. Tuesday

 

Snow lovers can hold out hope a heavier band develops on this storm’s northwest fringe dropping 1-3 inches over the metro region, but we think no accumulation is probably more likely than that.

Overnight lows range from 8-13 (suburbs-city) with winds from the north and northwest around 5-10 mph.

Tomorrow (Wednesday): Mostly sunny but very cold for one more day. Highs range from 22-26, with wind chills early in the day near zero, moderating into the single digits and teens during the afternoon. Winds are from the northwest at 10-15 mph.

See Matt Rogers’ forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

The cold patrol - January 23 (Kevin Wolf via Flickr)

The cold patrol – January 23 (Kevin Wolf via Flickr)

SchoolCast:

D.C. and counties to the west and north (including Montgomery and Fairfax)

1_apple

1 apple: expect school on time

Stafford, Prince William, Prince George’s, Anne Arundel and Charles counties

1.5_apple

1.5 apples:  50/50 chance of delay, 25 percent of closing

Calvert and St. Mary’s counties

2_apple

2 apples: 50/50 chance of closing, good chance of a delay. Still do your homework.

FedCast

fedcast-1-dome

1 dome: expect Federal government to open on time

 

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