D.C. area forecast: Snow this morning then little chance of winter letting go

* Delays & Closings | Snowfall totals from NWS *

11:45 a.m. update: Except for sections of our southeast suburbs, where some scattered snow showers and flurries linger, this storm has ended. This is the last update. Scroll down for the forecast through the weekend.


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.

10:55 a.m. Update: Snow is ending in downtown D.C. and skies are brightening, as the back edge of the snow pushes towards the south side of the Beltway, and is showing some signs of weakening. Winter weather advisories have been lifted in our north and west suburbs, including Montgomery, Howard, and Loudoun counties, where snow has ended and the sun is coming out. Still another 30-45 minutes or so of occasional snow showers for our southeast suburbs into Southern Maryland.

10:40 a.m. Update: The back edge snow burst is now heading into the southern half of the District and Fairfax County. Areas north of I-66 are mostly in the clear and sunshine is returning. To the southeast, radar shows an area of light to moderate snow in southern Prince George’s, Charles, and northern Calvert county – these areas have another hour or so of snow to go.

10:30 a.m. Update: Great sequence of back end burst which cut through Silver Spring, from Twitter:

10:25 a.m. Update: The sharpness of the back edge of precipitation is striking and cool to see zoomed in on radar. It’s currently cutting like a knife through the District and Fairfax County. Behind the back edge? Sunshine quickly emerges… sometimes in minutes.

Radar back edge  of snow at 10:20 a.m. (RadarScope)

Radar back edge of snow at 10:20 a.m. (RadarScope)

At 10:10 a.m.: . Georgia Ave at Wayne Ave, looking north on Georgia. Quarter-mile visibility or less at times.  (Andrew Chapman)

At 10:10 a.m. as the back edge of the snow cuts through Silver Spring: Georgia Ave at Wayne Ave, looking north on Georgia. Quarter-mile visibility or less at times. (Andrew Chapman)

10:10 a.m. Update: The western edge of the snow is now into central and eastern Howard and Montgomery counties, extending through western Fairfax County. It has weakened some on the southwest side, but there are reports of heavy snow on the north side around Columbia and into Baltimore. Most of the area is within an hour or so of this event ending (perhaps a bit longer in southern Maryland), and the sun is out from Leesburg and points west.

9:55 a.m. Update: This back end burst along the storm’s western edge means business with big fat flakes and moderate snowfall rates. But it’s snowfall output is limited by its fast forward speed. It has already progressed into central Montgomery and eastern Loudoun County, and will sink southeast inside the Beltway in the next half hour.

Here’s a radar grab from around 9:40 a.m.:

Annotated radar view from around 9:40 a.m. (RadarScope)

Annotated radar view from around 9:40 a.m. (RadarScope)

9:30 a.m. Update: As this disturbance pulls away, it’s showing signs of wanting to end with a bit of a bang. Radar shows a band of moderate snow developing on its back edge from roughly northern Howard County through western Montgomery County and extending west-southwest through central Loudoun County and into northern Fauquier County. Along and just to the southeast of that line, don’t be surprised to see snow pick back up and deposit a quick coating or so. Road conditions – which may have improved for a time – may go back downhill as this band comes through.

9:20 a.m. Update: Snowfall reports from around the region are pretty much all in the 1-2 inch range, as radar shows the back edge pushing southeast. Here are some totals from readers:

In D.C.: Takoma Park 2″, Tenleytown 1.5″, Columbia Heights 1″, Navy Yard 1″
In Virginia: Manassas Park 2″, Dale City 1.5″, Warrenton 1-1.5″, Vienna 1″, Ashburn 1″, Sterling 1″, Oakton 1″, Alexandria/Mt. Vernon 0.5-1″,
In Maryland: College Park 2″, Rockville 1.5″, Bethesda 1.5″

Here’s a link to additional reports from the National Weather Service in Sterling: Snow totals (note the 3.5″ report from the National Arboretum in the District is highly suspect)

8:55 a.m. Update: When does it end? Steady activity is already tapering northwest and west of the Beltway, where mostly scattered snow showers and flurries are occurring. The high resolution model simulation shown below shows it pushing south and east of I-95 after 10 a.m., and then concluding in southern Maryland around noon.  Based on radar, this seems like it may be about 30 minutes too slow (i.e. snow will end about 30 minutes or so sooner than this indicates), but it gives you a general idea.

HRRR high resolution model radar simulation between 9 a.m. and noon (WeatherBell.com)

HRRR high resolution model radar simulation between 9 a.m. and noon (WeatherBell.com)

8:15 a.m. Update: Just in the past 20 minutes or so, the back edge of the steady snow has started to edge toward the south and east. So accumulating snow may be mostly over now for areas west of I-95 and north of the District and I-66, with the exception of a band working east across central Frederick County and east into Carroll County (which haven’t seen much snow up to this point), and some steadier snow trying to hang on through parts of Montgomery County. Once the snow stops where you are, road conditions should rapidly improve, despite the cold temperatures, thanks to the sun shining through the clouds.

8 a.m. Update: Now over a half-inch in many spots, snow continues to fall steadily most everywhere except north of northern Howard, northern Montgomery, northern Loudoun and northern Fauquier counties. Plenty of reports of slick and snow-covered (and surprisingly untreated) roads and sidewalks out there. Travel is manageable, but requires extreme caution. Approximately two more hours of steady snow before it moves away to the east-southeast.

Scroll down below for earlier updates, and our full forecast through the weekend

 

 

7:05 a.m. Update: Snow, mainly light with some patches of moderate activity, is making for a pretty morning scene around town. But also some slick and snow-covered roads. So be very careful out there, especially since most schools have decided to open on time. Our forecast for an inch or so (i.e., anywhere from a half-inch to perhaps 2″ in spots) is mostly on track. The exception continues to be north and west in Carroll, Frederick, Loudoun, and far northern Fauquier), where snow has struggled to develop and may not accumulate much more than a dusting to half-inch. We should see snow exit from west to east starting around 10-10:30 a.m., though it may become lighter before then north and west of the District.

 

 

Simulated radar from the high-resolution HRRR model shows solid snow over the area at 8 a.m. (College of DuPage)

Simulated radar from the high-resolution HRRR model shows solid snow over the area at 8 a.m. (College of DuPage)

6:30 a.m. Update: Many places now have a coating on sidewalks and side streets as light to moderate snow continues to fall. Notably, the snow has not yet developed much in the usually snowier locales north and west in Carroll, Frederick and Loudoun counties (it has filled in for most of Fauquier County except the far northwestern fringe). We still expect the snow to expand at least somewhat into these areas in the next hour or snow, though accumulations there may ultimately struggle to reach 1″. Elsewhere, we’re still looking at an inch or so as the most likely amount, with locally higher or lower totals possible as described below.

5:50 a.m. Update: Snow has developed nicely across the area since around 5 a.m., with the steadiest and heaviest expected around 7-9 a.m., before tapering starting around 10-10:30 a.m. Even in areas north and west where it’s barely snowing now (Carroll, Frederick, Loudoun and northern Fauquier counties), you should see snow increase during the next hour or two. We still expect total accumulations to average around 1 inch, but with anywhere from around a half-inch to 2 inches the likely range, and some localized spots could approach 3″.

From 5 a.m. …

Today’s Daily Digit

A somewhat subjective rating of the day’s weather, on a scale of 0 to 10.

3
Most of us are ready to move on, yet Mother Nature hits the repeat button with light morning snow and 30s for highs.

Express Forecast

Today: Some snow likely in the morning. Highs: Mid-30s.

Tonight: Mostly clear and cold. Lows: Mid-teens to low 20s.

Tomorrow: Partly sunny, increasing breeze. Highs: Upper 30s to mid-40s.

FORECAST IN DETAIL

If you were hoping winter would quietly ride off into the sunset, this forecast is not for you. After another encounter with light snow this morning, we stay fairly cold right on into the weekend. The rest of the work week is mostly quiet as far as precipitation goes. But the weekend, and especially heading into the start of next week, could bring increasing chances of snow or mixed precipitation.

Today (Wednesday): Areas of snow remain likely this morning before ending from west to east by around 10-11 a.m. Accumulations probably range from around a half-inch to 2″. If a localized heavier band of snow sets up like it did yesterday, then some spots could see up to around 3″. The ground is a bit colder than yesterday morning, so the snow should stick better on roads (especially side roads) than it did yesterday. That means morning travel disruptions and school delays are likely. By afternoon we should be partly sunny and precipitation-free, but quite chilly with highs in the mid-30s, and breezes gusting near 20-25 mph from the northwest. Confidence: Medium

Tonight: Skies turn mostly clear, winds become light, and temperature start to sink. Overnight lows end up ranging form the the mid-teens in the colder outer suburbs, to the low 20s downtown. Confidence: High

For related traffic news, check out Dr. Gridlock. Keep reading for the forecast through the weekend…

Tomorrow (Thursday): An increasing morning breeze from the southwest provides a somewhat milder flow. That, as well as partly sunny skies, should help temperatures recover to afternoon highs at least in the upper 30s to low 40s. Afternoon breezes could gust near 25-30 mph from the west, and in doing so could carry enough mild air to push highs into the mid-40s. Confidence: Medium-High

Snow Potential Index

A daily assessment of the potential for at least ~1″ of snow in the next week, on a 0-10 scale

6 (↑) The SPI edges higher thanks to a little snow this morning plus storm risk early next week.

Tomorrow night: Winds remain breezy during the evening as they turn to come from the northwest, bringing in a reinforcing cold shot. Overnight lows head down to the teens area-wide. Confidence: Medium-High

A LOOK AHEAD

High pressure dominates Friday, keeping skies mostly sunny but holding highs to near 30 with light winds. Clouds increase again Friday night with lows in the upper teens to mid-20s (suburbs to city). Confidence: Medium-High

We stay on the cold side Saturday with a possible passing flurry or snow shower, and highs aiming for the upper 30s to mid-40s. Sunday highs should reach the 40s with the chance of a few scattered rain or snow showers, and then we’ll have to watch for an increasing risk of snow or mixed precipitation Sunday night and Monday. Confidence: Low

Also on Capital Weather Gang

PM Update: More snow, more mid-winter cold into Wednesday