11:00 AM | **Heavy showers and strong thunderstorms now closing in on the DC metro region...tornado watch for the DC metro region until 5PM; heavy showers and possible storms will reach the Philly metro region during the early-to-mid afternoon**

[latest radar courtesy University of Wisconsin (AOS)]

Discussion

DC An area of heavy showers and strong thunderstorms is now closing in on the DC metro region from west-to-east. This band of showers and thunderstorms is associated with a strong cold frontal system and it’ll arrive in the western suburbs of DC by 11am or so and then spread across the rest of the DC metro region during the mid-day hours. This line has prompted the National Weather Service (NWS) to put up a “tornado watch” for entire the DC metro region until 5PM with the greatest threat for severe weather from I-95 to points east.

Philly Farther north, the showers and thunderstorms will arrive in the Philly metro region during the early-to-mid afternoon hours (~1-3PM). Brief downpours are likely and there can be a strong thunderstorm or two mixed in. There is still some low-level cold air around in the Philly metro region as compared with DC and this should reduce the chance for severe weather north of the Mason Dixon line (11am observations: 40 degrees at Philly Airport, 63 degrees at Reagan National in DC), but it is possible that the NWS extends the "tornado watch" into SE PA later today.

7:00 AM | **A strong cold front brings brief downpours to the region during the mid-day hours and there can be a few strong thunderstorms with very gusty winds**

6-Day Forecast

Today

Cloudy, mild with occasional showers from later this morning into the mid-afternoon, some of the rain will come down hard for a brief time, a strong thunderstorm or two is possible and any storm can contain strong wind gusts, highs in the upper 50’s

Tonight

Becoming partly cloudy, turning colder, watch for black ice late, lows near freezing

Saturday

Mostly sunny, still mild, mid-to-upper 50’s

Saturday Night

Mostly cloudy, chilly, mid-to-upper 30’s

Sunday

Mostly cloudy, mild, slight chance for some rain or rain changing to snow late at night, mid 50’s

Monday

Partly sunny, colder, low 40's

Tuesday

Mostly cloudy, cold, chance for some snow at night, upper 30’s

Wednesday

Mostly cloudy, cold, chance for some snow, mid-to-upper 30’s

Discussion

A strong cold front will cross the region today and it will generate some brief downpours along with the possibility of a strong thunderstorm or two containing gusty winds from late morning into mid-afternoon. Temperatures will climb into the 50's ahead of the front, but a cooling trend begins this weekend and intensifies next week. In fact, a very winter-like and cold pattern will re-establish itself next week in the central and eastern U.S. and there will be snow threats as we close out February and head into March.

Video

httpv://youtu.be/Lqcw-jnQ4n8

12:00 PM | **Winter comes roaring back next week with bitter cold and multiple snow threats**

[map courtesy Penn State eWall]

Discussion

“Siberian-connection”, “polar vortex” and “omega-block” may become part of the weather dialogue in the eastern half of the nation as we close out the month of February and begin the new month of March since it appears winter will make a roaring comeback following the current brief mild spell. A strong cold front moves through the Mid-Atlantic region on Friday and it will be accompanied by brief downpours and possible strong thunderstorms. Temperatures on Friday will spike well into the 50’s ahead of the cold front in much of the Mid-Atlantic region, but a cooling trend begins later this weekend and then much colder air returns next week.

Last night’s 00Z GFS 500 millibar forecast map (above) for the 7-10 day time period supports the idea that a deep trough of low pressure will form in the southeastern part of Canada (blue) and a strong ridge of high pressure (red/orange) will extend northward along the west coasts of the U.S. and Canada [map courtesy Penn State eWall]. The combination of these two upper-level features will likely force numerous Arctic air masses to drop southward from central Canada into the central and eastern U.S. next week and beyond – just as it did earlier this winter. In fact, one such air mass that is destined to reach the northern U.S. later next week will cross the North Pole from Siberia in the next couple of days and then plunge southward through Canada towards the northern U.S. To make matters worse, the high pressure ridging that virtually surrounds the eastern trough is reflective of an “omega-shaped” blocking pattern in the upper atmosphere that promises to keep the cold air in place for an extended period of time in the central and eastern U.S. Yesterday’s GFS Ensemble 850 millibar temperature forecast map (below) shows the coldest air in North America centered over the western Great Lakes region during the middle of next week and this is reflective of a pattern in which the usual “polar” vortex is distributed to the mid-latitudes [map courtesy WeatherBell Analytics].

[map courtesy WeatherBell Analytics]

As far as snow is concerned, this upcoming pattern will produce multiple snow threats with more accumulating snow almost a certainty and there is an increasing chance for another major snowstorm in the Mid-Atlantic region. The first threat for snow will come in the Sunday night/early Monday time period when the initial batch of cold air arrives into the Mid-Atlantic region. A second threat comes late Tuesday into Wednesday as another wave of energy approaches the Mid-Atlantic region. Finally, a third threat could arrive late next week or early next week (Friday/Saturday) as a strong system looks like it may pull out of the Deep South and heads to the east coast, but it is way too early to tell how far up the coast this storm can go - certainly something to monitor. Today’s video discussion focuses in on the cold - and potentially snowy weather pattern - for next week and beyond.

Video

httpv://youtu.be/hil97z3Faqo

7:00 AM | Possible downpours on Friday morning as strong cold front passes through the region; cooling trend this weekend evolves into a cold pattern to close out February and begin March

6-Day Forecast

Today

Mostly cloudy skies today and quite mild, highs in the mid 50’s

Tonight

Cloudy, mild, some rain or drizzle with patchy fog, lows in the mid 40’s

Friday

Cloudy, windy, very mild with occasional showers during the morning and mid-day hours, some of the rain can be briefly heavy, a thunderstorm is also possible with strong wind gusts, upper 50’s

Friday Night

Becoming partly cloudy, turning colder, low 30's

Saturday

Mostly sunny, still mild, upper 50’s

Sunday

Partly sunny, breezy, mild, low-to-mid 50's

Monday

Mostly sunny, colder, low 40's

Tuesday

Mostly cloudy, cold, chance for some snow, mid-to-upper 30’s

Discussion

A strong cold front will cross the region on Friday morning and it will generate some brief downpours along with the possibility of a thunderstorm containing strong wind gusts. Temperatures on Friday will climb to well up in the 50’s, but then a cooling trend will take over for the upcoming weekend. Next week looks to be quite cold as the overall weather pattern returns to the type seen earlier this winter with a deep trough in the eastern US and a strong ridge along the west coast. This pattern will likely bring multiple Arctic air outbreaks and snow threats into the Mid-Atlantic region as we close out February and begin the new month of March.

Video

httpv://youtu.be/hil97z3Faqo

7:00 AM | Rain today with a rumble of thunder in some areas and icing possible in the far N and W subrubs; should get into the 60's on Friday

6-Day Forecast

Today

Rain moves in this morning and maybe even a rumble of thunder mixed in, in the far N and W suburbs there can be some freezing on some surfaces and ice pellets can mix in, becoming partly sunny and milder this afternoon, highs in the low-to-mid 50’

Tonight

Partly cloudy, cold, lows near 30 degrees

Thursday

Partly sunny, mild, near 50

Thursday Night

Mostly cloudy, chilly, some rain and patchy fog possible late, upper 30’s

Friday

Mostly cloudy, very mild, windy, some more rain is likely, possibly a thunderstorm with strong gusts, low 60’s

Saturday

Cooler and partly sunny, near 55

Sunday

Partly sunny, breezy, even cooler, near 50

Monday

Partly sunny, chilly, upper 40’s

Discussion

A weak system could throw some light rain our way this morning, but then partial sunshine will return for the afternoon with temperatures climbing to the 50’s. By Friday, as a strong cold front approaches from the west, temperatures could actually reach the low 60’s along with some rain and possibly even a thunderstorm. It’ll gradually turn cooler over the weekend and then a return to much colder weather is likely by the middle of next week.

Finally, some impressive snowfall numbers from this winter: 6th snowiest winter on record in NYC, 5th snowiest ever in Chicago, 3rd snowiest ever in Philly, and the 4th snowiest winter in the last 25 years in DC.

Video

httpv://youtu.be/YZDE50RISoY

7:00 AM | Much milder conditions takeover for a few days with 60+ degrees likely on Friday

6-Day Forecast

Today

Becoming mostly sunny, milder, highs in the mid 40's

Tonight

Becoming cloudy, chilly, lows near 30 degrees

Wednesday

Cloudy in the morning with a few rain showers possible, partly sunny and mild in the afternoon, low-to-mid 50’s

Wednesday Night

Partly cloudy, chilly, near 30

Thursday

Mostly cloudy, mild, breezy, maybe a shower or two, near 50

Friday

Cloudy, very mild, windy, chance for some rain and possibly even a strong thunderstorm with gusty winds, low 60's

Saturday

Cooler and partly sunny, low-to-mid 50's

Sunday

Partly sunny, cool, low 50's

Discussion

The quick thumping of snow early this morning that dropped anywhere from a coating to an inch or two was associated with milder air trying to advance into the Mid-Atlantic region and it will finally succeed and become noticeably milder during the second half of the week. A strong cold front, however, will cross the region on Friday and this will begin a downward trend in temperatures after a 3-day break in the cold during the Wednesday, Thursday and Friday time period. The front may actually generate some strong thunderstorm activity in the Mid-Atlantic region on Friday with some gusty winds while temperatures climb to or just past the 60 degree mark. Much colder air will return to the region later next week.

11:45 AM | ***Accumulating snow late tonight and early Tuesday with increased totals***

Discussion

There is something about the President’s Day holiday and snow that just seem to go together. Low pressure will move well north of the Mid-Atlantic region later tonight and early Tuesday, but a second area - supported by strong upper-level dynamics and upward motion - will try to organize farther south along the coastline (see 12Z NAM surface forecast map for early Tuesday). This secondary low pressure system combined with advancing milder air from the southwest will likely generate a "quick thumping" of "warm advection" type snows late tonight and early tomorrow in the DC, Philly, NYC corridor. In fact, the recent trend in most of the computer forecast models has been to increase precipitation totals for this upcoming event from late tonight into early Tuesday.

As a result, snowfall accumulation estimates have been bumped up to 2-4 inches in the DC metro region, and 3-6 inches in the Philly and NYC metro regions (mixing issues on Long Island cut accumulations in that area). As far as the timetable is concerned: in the DC region, snow begins around midnight and ends early in the morning, in Philly, the snow begins after midnight and continues until mid-morning, and in the NYC metro region the snow begins towards morning and continues there until midday. In all locations along the I-95 corridor the heaviest snow will come in a "burst" and there is the chance that the snow mixes with or changes to sleet and/or freezing rain for awhile before ending on Tuesday after the precipitation intensity diminishes. Numerous slick spots are possible for the Tuesday morning commute and - at least in Philly and NYC - the snow could actually be falling at its heaviest rate right around the morning rush hour.

Milder conditions move in for the second half of the week, but winter is far from over as there are signs for much colder air to return later next week.

[NAM precipitation totals for the upcoming storm]

7:00 AM | ***Finally - a break in the pattern this week to bring 60 degrees to the region - but first more accumulating snow***

6-Day Forecast

Today

Sunshine followed by increasing cloudiness, brisk and cold, highs in the mid 30’s

Tonight

Becoming cloudy with some snow developing by midnight and it could mix with or change to sleet and/or freezing rain towards morning, cold, lows near 25 degrees

Tuesday

Cloudy, brisk and still cold in the morning with snow or a wintry mix winding down then partial clearing in the afternoon and becoming milder, 1-3 inches of new snow accumulations, mid-to-upper 40’s

Tuesday Night

Partly cloudy, cold, upper 20’s

Wednesday

Partly sunny, even milder, maybe a shower, mid 50’s

Thursday

Cloudy, very mild, chance for a few rain showers, mid-to-upper 50’s

Friday

Mostly cloudy, still very mild, chance for some rain, near 60

Saturday

Partly sunny, not as mild, maybe a few showers, low 50’s

Discussion

The big news this week is that noticeably milder conditions will finally move into the Mid-Atlantic region, but we’ll have to get through more accumulating snow before we get there. Yet another system dropping southeastward from Canada will push snow into the region late tonight and early Tuesday and this snow could change briefly to sleet and/or freezing rain before ending tomorrow. 1-3 inches of new snow accumulations are likely and the Tuesday morning commute will likely have numerous slick spots. Once this system departs the region by later Tuesday, milder air will begin to filter into the area and high temperatures in the 50’s are likely on Wednesday and Thursday. This week's break to milder weather conditions does not signal the end of winter and we'll actually begin to cool down some this weekend with much colder air likely to return later this month.

Video

httpv://youtu.be/Npn0kmRBhS8

1:45 PM | **More accumulating snow for the Mid-Atlantic region on Saturday**

Discussion

The next storm coming down the pike has quite an impressive upper-level trough that is actually eerily similar to yesterday’s powerful coastal storm, but it is likely to move too quickly through the Mid-Atlantic region for major snow accumulations. Still, the next storm is nothing to sneeze at and moderate snow accumulations are very likely. As the storm intensifies rapidly on Saturday while moving up along the east coast, there will likely be increasing snowfall accumulations as one goes northeast along I-95. In fact, by the time the storm reaches eastern New England, major accumulations and blizzard conditions are quite likely.

The 12Z GFS 24-hour 500 millibar forecast map (above) for Saturday morning shows a deep upper-level trough in the Southeast US – similar in many ways to that associated with yesterday's powerful coastal storm. The 12Z GFS 36-hour surface forecast map (below) for early tomorrow afternoon shows low pressure off the Mid-Atlantic coastline after having traveled rather quickly from central North Carolina in just a six-hour time period. Snowfall accumulation estimates for tomorrow are 1-3" in DC where the road surfaces will be quite warm, 2-4" in Philly, 3-6" in NYC, and at least 6-10" in Boston with blizzard conditions extending from eastern Massachusetts to eastern Maine. The timetable for the snow in the DC-to-Philly-to-NYC corridor is generally from early morning into the late afternoon hours on Saturday.

Looking ahead, more accumulating snow is likely late Monday night and early Tuesday in the Mid-Atlantic region, but that next round of wintry weather will transition us to milder conditions for awhile beginning later Tuesday afternoon - and 50 degrees is possible for high temperatures by late next week.

7:00 AM | ***One storm ends and another approaches...more accumulating snow late tonight/early Saturday***

6-Day Forecast

Today

Mostly sunny, brisk and cold, highs in the upper 30’s

Tonight

Becoming cloudy with some snow developing late, cold, lows in the low-to-mid 20’s

Saturday

Cloudy, brisk, cold with periods of snow in the morning, new accumulations of 2-4 inches, near 35

Saturday Night

Mostly cloudy, very cold, upper teens

Sunday

Partly sunny, very cold, near 30

Monday

Partly sunny, cold, chance for snow, sleet and/or rain at night, upper 30’s

Tuesday

Cloudy, not as cold, chance for rain showers, low-to-mid 40’s

Wednesday

Partly sunny, still pretty mild, upper 40’s

Discussion

First the good news...the sun is out, the major coastal storm is over, and 50 degrees is possible next week. Now the bad news...there is more accumulating snow and very cold weather before we get there. One storm is over, but another one will intensify along the Mid-Atlantic coastline on Saturday and it could generate another 2-4 inches of snow for the region from very late tonight through about mid-day on Saturday. Another round of snow, sleet and/or rain is possible Monday night before milder air moves in on Tuesday.

Video

httpv://youtu.be/PnXFlCMSLlg