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Winter storm warning: Disruptive mix of snow and sleet into tonight (LIVE UPDATES)

** For immediate D.C. area,  winter weather advisory 5 p.m. tonight to 1 a.m. Friday morning | Winter storm warning through 5 a.m. Friday north and west of the immediate metro area | Winter weather advisory 5 p.m. tonight through 1 a.m. Friday morning in southern Maryland **

Snow totals | Zoomable snow total mapStorm news live blog *

The storm’s final wave is arriving.

Key points:

  • Energetic upper level disturbance to sweep through D.C. area between roughly 3 and 11 p.m. tonight
  • Precipitation may begin as a mix, but should change over to snow.  Thunder is possible.
  • Snow may be heavy at times, especially between around 6 and 9 p.m. tonight.
  • Accumulations of 1-4 inches possible, and locally higher amounts cannot be ruled out.
  • This disturbance has a history of producing very heavy snow: 6″ in 3 hours in Roanoke

For more details on this final wave of snow and to comment on what’s happening, go to this post: Storm Snochi may end with a bang

Goodbye storm Snochi; encore event on the way?

Storm Snochi is almost outta here, save for some lingering snow showers mainly east of town through around midnight. That makes this the last update to this live blog.

So go out and shovel if you  haven’t, but even when you’re done, you may want to keep that shovel handy. Believe it or not, we’ve got a chance of a little more snow Friday night into midday Saturday. See more details in our latest post on the main Capital Weather Gang blog, and remember to watch out for icy spots tomorrow morning.

Snow subsiding, to be replaced by more slipping and sliding

This storm is finally fading away for the D.C. area, with snow starting to dwindle as seen in the radar loop below, though still hanging on for a bit in the eastern half of the region.

radar_loop_944

As the snow fizzles, we now turn our attention to temperatures falling to lows in the mid-to-upper 20s, and a Friday that may not see temperatures above freezing until late morning, or even around noontime for some of the colder north and west suburbs.

Hourly temperatures next 24 hours for Washington, D.C. (NWS)

Hourly temperatures next 24 hours for Washington, D.C. (NWS)

So yes, plan for some slipping and sliding if you must head out in the morning.

Snow totals now over 20 inches well north and west of the District

With the snow finally showing signs of coming to an end, it’s clear that many spots beat expectations by at least a few inches. The National Weather Service is out with a new list of snow totals. Most are old reports from earlier in the day before the second round. But below I pulled a few that are all from no earlier than 7 p.m. Look at some of these numbers!…

Crofton (Anne Arundel): 10.0″
Westminster (Carroll): 24.0″
Damascus (Montgomery): 21.3″
Alexandria: 8.0″
Gleedsville (Loudoun): 17.0″
Dulles Airport (Loudoun): 13.1″

Generally speaking, it sounds like most spots picked up an additional 1-3″ with this second round of snow, even in the District as seen below…

Snow: mapped by Twitter

Want to know where it snowed in this storm? Check out this cool map created by Twitter.

(Twitter)

(Twitter)

The map is based off tweets that mention the word snow (no, it didn’t snow in Miami). They also have an interactive where you can zoom way in and watch things progress.

Twitter’s snow map matches up quite well to where actual snow has been reported to the NWS in the past 24 hours, as seen below.

(NOAA)

(NOAA)

Note: In the map above, reports are still coming in. For instance, New England saw snow today but hasn’t been added yet.

Recent radar loop shows the beginning of the end

(Weather Underground)

(Weather Underground)

During the last two to three hours, snow bands dropping occasionally moderate to heavy precipitation have been swinging through the immediate D.C. area. Reports from this activity thus far range from as little as a dusting in spots still just above freezing to about 3 inches. Some folks even more than that, mainly to the east and northeast of downtown.

It’s almost over, especially the further west you live. The final edge of snow should push toward D.C. by around 10 p.m. or so, and shift east thereafter.

Watch live radar, let us know how much you have seen this evening, and tell us when it ends at your location over on the main CWG blog.

Metrobus suspension through 5 a.m. Friday

Thanks to the new round of snow moving through this evening, WMATA has shut down bus service until early tomorrow morning. Buses will resume at 5 a.m. with limited lines in operation. Important details below.

Metrobus service will remain suspended until 5 a.m. Friday. Starting at 5 a.m., Metro will run limited bus service on major arteries, similar to this afternoon’s service.

The following routes are expected to have limited service, if conditions permit:

District of Columbia: 32, 36, 52, 54, 70, 90, 92, A6/A8, S2, X2

Maryland: 83, A12, C4, C22, D12, F4, J2, K6, P12, Q1, T18, Y9

Virginia: 1A, 2A, 3A, 4A, 7A, 9A, 10B, 16A, 22A/25A, 23A, 28A, 29N

Read the full release

Storm center still close, but pulling away

Mesoanalysis of the northeast this evening showing the location of the surface low pressure. (Storm Prediction Center)

Mesoanalysis of the northeast this evening showing the location of the surface low pressure. (Storm Prediction Center)

The heaviest snow bands are beginning to shift east of I-95 overall, but snow is still flying everywhere at this time. In the last hour, our strong low pressure system was located just offshore southern New Jersey.

With a central pressure of ~986mb, the storm is about as strong (if not quite as snowy) as well known ones in the past like Snowmageddon in 2010.

It’s also a beauty on satellite. Note the comma head over the D.C. area:

(NASA)

(NASA)

Generally, as a storm gets north of our latitude the snow threat begins to diminish fairly quickly. We’ll see that occur over the next few hours.

Snow piling back up

It’s almost like this was two storms given the extended break in the middle. The second part is putting fresh powder on top of our snow-pack from last night into this morning.

Here’s a quick roundup of what it’s looking like across the area this evening:

Thundersnow reported

Vigorous snow bands currently pushing through the region are being enhanced by a powerful mid-level storm swinging by to our south and southeast. It is interacting with the surface low off the coast. The dynamics are helping to create another round of lightning in the area this evening, with some reports of thundersnow.

This activity should remain isolated but is always very interesting to see!

(WeatherBug iPhone App)

(WeatherBug iPhone App)

Snow bands sweeping across area

Radar around 7 p.m. (GR2Analyst)

Radar around 7 p.m. (GR2Analyst)

It’s not quite the overall intensity seen last night, but snow is now falling moderately to heavily in parts of the area as the grand finale of this storm reaches its local peak.

If you’re way west, out near the Blue Ridge and west, the back edge is already approaching. That will continue to push east, but may still take a few hours. Radar trends and short-range models continue to indicate snow should end by the 10-11 p.m. period as shown in the latest HRRR radar simulation at 11 p.m.:

(Weatherbell.com)

(Weatherbell.com)

Even into the city, roads are picking up additional accumulation following today’s melting.

Freezing temperatures returning, dropping into 20s after snow

A good portion of the area saw temperatures rise at least a little past freezing today, helping snow melt off and causing slushy passageways as well as numerous puddles. With snowfall picking back up over the area, temperatures have fallen to within a few degrees of freezing most spots.

Temperatures across the area during the 6 p.m. hour. (Weather Underground's WunderMap)

Temperatures across the area during the 6 p.m. hour. (Weather Underground’s WunderMap)

While the temperature drop will be quite slow for the remainder of the event, re-icing is already going on across a good part of the area, particularly I-95 and northwest. Temperatures may more or less hover near where they are through the finish as seen in the 11 p.m. forecast from the NAM weather model below.

Hi resolution NAM forecast temperatures for 11 p.m. tonight. (Weatherbell.com)

Hi resolution NAM forecast temperatures for 11 p.m. tonight. (Weatherbell.com)

However, once the storm begins to pull away, cooler and drier air will filter into the area more readily, sending temperatures down more substantially in the post midnight period. In the 2 a.m. NAM forecast below, significantly colder air is seen streaming in from the west.

Hi resolution NAM forecast temperatures for 2 a.m. tonight. (Weatherbell.com)

Hi resolution NAM forecast temperatures for 2 a.m. tonight. (Weatherbell.com)

With lows reaching the near 20 to upper 20s range, travel will remain quite tricky through the night and likely into tomorrow.

NWS: Expect moderate to heavy snow next several hours

The National Weather Service just issued the following Special Weather Statement:

..HEAVY SNOW TO IMPACT AREAS EAST OF BLUE RIDGE INCLUDING THE GREATER METROPOLITAN AREAS OF WASHINGTON AND BALTIMORE THROUGH MIDNIGHT…

AREAS OF MODERATE TO HEAVY SNOW WILL IMPACT THE REGION THROUGH MIDNIGHT…WHERE 2 TO 4 INCHES OF NEW SNOWFALL ACCUMULATION CAN BE EXPECTED AS AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE AREA. AT 600 PM…MOST LOCATIONS HAVE TRANSITIONED TO ALL SNOW AFTER THE SLEET AND RAIN FROM EARLIER IN THE AFTERNOON.

THE AREAS OF HEAVIEST SNOWFALL WILL OCCUR ALONG AND EAST OF INTERSTATE 95…AND ALSO IN HOWARD AND CARROLL COUNTIES IN MARYLAND.

THIS ADDITIONAL SNOWFALL WILL MAKE TRAVEL HAZARDOUS AS ROADS WILL ONCE AGAIN BECOME SNOW COVERED. VISIBILITIES WILL BE LOWERING TO BELOW 1/4 MILE AT TIMES…SO TRAVEL IS NOT ADVISED UNLESS ABSOLUTELY NECESSARY.

Snow starting to accumulate in final round

The snow is falling steadily and starting to stick, especially along and east of I-95 where the rate of snowfall is the heaviest. The way it looks now, it would appear areas right along I-95 could get around 1-3 additional inches before this ends (probably between 10 and 11 p.m.), locations east of I-95 2-4″, and west of I-95 1-2″.

Some reports:

Heaviest snow developing along and east of I-95

In a way, perhaps, the storm’s closing act is trying to even out the snow distribution. Whereas the heaviest snow overnight and this morning west of I-95, this end-game band is favoring the I-95 corridor and especially locations just to the east.

Radar view around 5:20 p.m. (RadarScope)

Radar view around 5:20 p.m. (RadarScope)

As the snow is falling, temperatures are edging back towards the freezing mark, so roads will be turning slick again this evening. This snow is likely to continue for the next few hours, with accumulations 1 to 4 inches.

Whereas we had earlier said we favored western zones for more snow, it’s looking like areas along and just east of I-95 have the best chance of picking up a few inches.

Mixed precipitation changing back to snow in area

As the heavy areas of precipitation to the south and east envelop the area, they are gradually changing from mixed to snow.

Some reports:

SchoolCast and FedCast

SchoolCast:

Many school systems have already decided to close tomorrow and I imagine many of those that haven’t already will.

schoolcast-3.5-apples

3.5 apples: Schools are closed or very likely (90 percent chance or better) will close

FedCast:

fedcast-3-domes

3 domes: Greater than 90% chance of unscheduled leave policy and/or delayed opening. 50% or less chance of shutdown.

Conditions to deteriorate next hour or so

The very heavy band of precipitation south of the District, which may contain thunder, is heading north. Reports are that it’s initially a mixed bag of sleet and rain but transitions to more snow as time wears on. Rain and sleet changed back to snow in Richmond.

Wunderground radar image, 4:30 p.m.

Wunderground radar image, 4:30 p.m.

Also, snow has resumed in Warrenton.

Thunder possible with bands of precipitation coming in

The upper level disturbance swinging through the region is quite vigorous and profiles of the atmosphere show it be unstable. As such, thunder may well accompany some of the bands of snow and sleet coming through.

Radar at 4:00 p.m. (RadarScope)

Radar at 4:00 p.m. (RadarScope)

Just like summer thunderstorms, determining exactly who gets hit hardest is difficult. But radar shows areas of convection (fancy word for thunderstorms) north of Bowie in northern Prince George’s and northwest Anne Arundel counties – several reports of thunder have come in from around Laurel and Greenbelt.

A larger area that may contain thunder spans from Fredericksburg, Virginia into southern Maryland. This area is heading up the I-95 corridor towards the Beltway and D.C.’s eastern suburbs.

#Snochi: More to come Thursday night (VIDEO)

In this video update, I make clear the Washington area isn’t in the clear yet and can expect another blast of snow Thursday evening.

(Note this video update was made before seeing some the latest models which indicate slightly more snow than I let on above)

Storm's final round entering region

Reports of sleet have started to reach the metro area as the storm’s final wave lifts north.

final-round

In the immediate metro region, precipitation will almost certainly begin as a mix, but should gradually transition to snow towards dark. Some thunder cannot be ruled out. CWG’s winter weather expert Wes Junker says the atmosphere may well be unstable.

The NAM model tracks the heaviest precipitation from this disturbance through the metro region. On the other hand, the HRRR and RAP (high resolution) models forecasts the heaviest just east of town. It’s very difficult to say for sure where the most precipitation will fall, but – based on radar trends – I’m leaning just east of I-95.

Some reports:

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