7:00 AM | Snow showers ending this morning as one coastal storm departs then another coastal storm threat continues for early next week

6-Day Forecast

Today

Snow showers ending this morning then a mix of clouds and sun for the afternoon, breezy, cold, highs only 40 degrees (normal high at Reagan National Airport is now 57 degrees)

Tonight

Partly cloudy, cold, lows in the mid-to-upper 20’s

Friday

Mostly sunny, still breezy and cold, mid-to-upper 40’s

Friday Night

Mostly clear, cold, upper 20’s

Saturday

Mostly sunny, cold, near 50

Sunday

Increasing clouds, cold, chance for rain or snow at night, low-to-mid 40’s

Monday

Cloudy, cold, chance for rain or snow, low 40’s

Tuesday

Partly sunny, cold, upper 40’s

Discussion

Low pressure off the Mid-Atlantic coast will pull farther away this morning after lingering morning snow showers and it’ll leave behind a very chilly air mass for this time of year. High temperatures this afternoon are likely to only reach the 40 degree mark – some 15-20 degrees below normal for this date. Colder-than-normal weather will continue around here right into the weekend and at the same time a significant storm will be crossing the country. This storm will head towards the Ohio Valley on Sunday and from there it’ll begin to transfer its energy to a developing Mid-Atlantic coastal storm which could generate some rain or snow around here in the Sunday night/Monday time frame.

Video

httpv://youtu.be/pGlQvMMRsX0

2:30 PM | Snow brushes the I-95 corridor late tonight/early Thursday; early week significant storm threat continues

Discussion

A strong cold front passed through the region on Tuesday and a secondary cold front is sliding through the area right now and it could generate a snow shower or two during the evening hours. This second shot of cold air will help to intensify low pressure off the Mid-Atlantic coast later tonight and, as the low intensifies, it’ll brush the I-95 corridor from DC-to-Philly-to-NYC with snow showers late tonight and tomorrow morning. While there can be some slick spots for the morning commute with a coating or so of snow along and west of I-95, the best chance for an inch or two will likely be on the east side of I-95 in places like coastal Delmarva, coastal New Jersey, New York City, Long Island and Boston.

Looking ahead, a more significant coastal storm threat continues for early next week (Sunday night/Monday) in the Mid-Atlantic region. The latest model runs continue their recent theme with a primary low pressure system that heads into the Ohio Valley early next week and then transfers its energy to a developing coastal low. This transfer of energy occurs rather late in the game with the latest GFS model run compared to some of the other models and, given the (“omega”) blocking pattern expected across Canada at this time, it would not be too surprising to see a different handling of the primary low in subsequent GFS model runs. Last night’s 00Z Euro run, for example, moved the primary low no farther north than West Virginia whereas this latest 12Z GFS run places the low as far north as northwest Pennsylvania early next week before the transfer of energy takes place – an important difference with respect to potential snowfall in parts of the Mid-Atlantic given the marginally cold conditions expected.

Stay tuned on this one.

7:00 AM | Coastal low could throw snow showers back into the region late tonight/early Thursday

6-Day Forecast

Today

Sunny for much of the day, but some clouds roll in late, breezy, cold, highs near 50 degrees

Tonight

Becoming cloudy, cold, rain or snow shower possible early then snow showers likely late, lows in the upper 20’s

Thursday

Snow showers early with possible slick spots then a mix of clouds and sun in the afternoon, breezy, cold, upper 30's

Thursday Night

Partly cloudy, brisk and cold, mid 20’s

Friday

Mostly sunny, cold, mid 40’s

Saturday

Mostly sunny, cold, upper 40’s

Sunday

Partly sunny, breezy, cold, mid-to-upper 40’s

Monday

Mostly cloudy, chilly, chance for rain or snow, low-to-mid 40’s

Discussion

Not sure if you can postpone the beginning of spring, but if it were possible, this is a case where it should be done. Actually, spring has officially begun this morning if you take a look at the calendar; however, there is no spring-like weather pattern in sight. A blocking pattern in the upper atmosphere will keep us generally below normal through the rest of March and perhaps well into the month of April.

In the near term, an area of low pressure will form later today along a secondary cold front as it heads towards the east coast and the low will likely produce snow showers around here late tonight and early Thursday. Slick spots are quite possible for the morning commute as a coating of snow could form on grassy areas and untreated road surfaces with low temperatures overnight ending up just below freezing. Cold high pressure from Canada will then control the scene to close out the work week and begin the weekend with temperatures remaining below normal for this time of year. A storm will form in the southeastern states late in the weekend and it’ll have to be monitored for a possible turn up the coast early next week which could give us the chance for rain or snow on Monday.

Video

httpv://youtu.be/IenD1t5AhMM

12:20 PM | Could be a wild and interesting beginning to spring

Discussion

Spring will begin officially get underway tomorrow, but there is no spring-like weather pattern in sight for the Mid-Atlantic region. In fact, the overall weather pattern may actually get colder and stormier before it gets better.

Last week we talked about the development of an impressive “omega-shaped” blocking pattern in the upper atmosphere to our north and that process is now well underway. Specifically, “omega-shaped” blocking refers to strong winds in the upper atmosphere that take on the shape of the Greek letter “omega” with large southward dips and northward bulges. This type of upper atmospheric blocking pattern will affect the temperature pattern in the Mid-Atlantic region in a couple of ways. First, it will act to force additional cold air masses into the central and eastern US from northern Canada and secondly, it will prevent any of the warm air building up in the southwest US from expanding into the northeastern US – at least not on any kind of consistent basis – through the rest of the month of March and perhaps right into early April.

Two forecast indices that can provide clues about this “omega-shaped” blocking pattern in the upper atmosphere include the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO). These index values are related to the “oscillation” between the pressure differences in the North Atlantic and when they are consistently in negative territory, atmospheric blocking patterns often form in the northern hemisphere. In fact, both of these indices have been dropping sharply in the last few days into deep negative territory not seen in months.

The colder-than-normal temperature pattern will continue to be quite active as well which is not surprising given the developing northern hemisphere blocking pattern and indeed, there are growing signs for significant coastal storms next week. Last night’s 00Z European model run not only features a “threatening-looking” coastal storm early next week that bears watching, but it also generates a second storm late in the week - exactly how far north they go in this blocking environment is still to be determined. The GFS computer forecast model has also been generating a coastal storm threat in its forecast for early next week.

Stay tuned…the beginning of spring could be quite wild and interesting in the Mid-Atlantic region. On the positive side, there is one definite sign of spring - Opening Day is now less than two weeks away.

7:00 AM | Noticeably milder this afternoon compared to Monday, but warm up will be short-lived

6-Day Forecast

Today

Cloudy this morning then becoming mostly sunny, breezy and milder, highs in the mid 50’s

Tonight

Mostly clear, cold, breezy, lows near 30 degrees

Wednesday

Some sun early, clouds late, breezy, mid 40’s

Wednesday Night

Rain or snow showers possible late, brisk and cold, upper 20’s

Thursday

Partly sunny, cold, low 40’s

Friday

Mostly sunny, cold, mid-to-upper 40’s

Saturday

Partly sunny, breezy, chilly, upper 40’s

Sunday

Increasing clouds, chilly, mid-to-upper 40’s

Discussion

It’ll turn briefly milder today just ahead of a strong cold front that will usher in colder air for the middle and latter parts of the week. An area of low pressure will form tomorrow along a secondary cold front as it heads towards the east coast and the combination could produce rain or snow showers around here tomorrow night. Cold high pressure from Canada will then control the scene to close out the work week and begin the weekend with temperatures remaining below normal for this time of year. Next week is taking on a stormy look with one potential storm to deal with early in the week and then a possible second storm later in the week.

Video

httpv://youtu.be/VpEaYIUGEqs

12:00 PM | Mixed precipitation arrives in SE PA during the mid-to-late afternoon hours and a short time later in NYC

Discussion

A band of snow that produced a coating to an inch or so outside the beltway to the west of the District of Columbia this morning eroded while moving northeast towards southeastern Pennsylvania as it encountered a deep layer of dry air entrenched in this region. Dew points continue to hold at dry levels (in the teens) at mid-day across SE PA, but the atmosphere will become moist enough by the mid-to-late afternoon to allow for the development of a mixed bag of precipitation including sleet, snow and rain. Once the precipitation begins, temperatures will drop a few degrees at the onset due to some evaporational cooling effects. The mixed precipitation should last for a few hours in SE PA before a changeover to plain rain occurs later tonight. The rain will continue overnight and into tomorrow morning and some of the rain can come down hard at times. Snow or mixed precipitation should reach the New York City metro region late this afternoon or early this evening and continue there until late tonight at which time a changeover to plain rain is expected. Snow can come down quite heavily for awhile this evening in the NYC metro region after the initial round of mixed precipitation drops temperatures a few degrees. Snow and ice accumulations on the order of a trace to a couple of inches are possible from later today into later tonight in both the Philly and NYC metro regions, primarily on grassy surfaces to the N and W of the two cities. The DC region may have some sleet mixed in later this afternoon when precipitation resumes in that area, but the main form from here on out down there will be plain rain.

Looking ahead, despite a brief warm up tomorrow just ahead of a strong cold frontal passage, this overall winter-like pattern will continue for the second half of the week and beyond with the next threat for some snow or snow showers coming late Wednesday night or early Thursday. An even bigger storm threat is possible early next week. The good news – Opening Day is only 2 weeks away.

7:00 AM | *Rare "post-March 15th" accumulating snow throughout the District region this morning*

6-Day Forecast

Today

Cloudy with a burst of snow during the early-to-mid morning hours that will slacken off by late morning only; preciptiation then resumes later this afternoon in the form of sleet and/or rain, accumulations of a coating to a couple of inches during the early-to-mid morning hours; especially, on grassy surfaces to the west of the District and in higher elevation locations, highs in the upper 30's

Tonight

Cloudy, rain likely, lows in the mid 30’s

Tuesday

Cloudy in the morning with showers likely then some clearing possible during the afternoon, milder, breezy, low 50’s

Tuesday Night

Becoming partly cloudy, windy, cold, low 30’s

Wednesday

Partly sunny, windy, cold, snow showers possible in the PM, mid-to-upper 40’s

Thursday

Partly sunny, brisk and cold, mid-to-upper 40’s

Friday

Mostly sunny, cold, upper 40’s

Saturday

Partly sunny, breezy, cold, upper 40’s

Discussion

Another major winter storm will affect the Northeast US over the next 48 hours or so with a mixed bag of precipitation in and around the local area and more significant snow accumulations in New England. This storm will swing a strong cold front through the Mid-Atlantic region later tomorrow and that will usher in more cold air for the middle and latter parts of the week – setting the stage for a cold second half of the month of March.

Snow broke out late last night in parts of Virginia and West Virginia ahead of the approaching strong cold front and a burst of accumulating snow is now winding down in the DC metro region with accumulations of a coating to an inch or so; especially, on grassy surfaces to the N and W of the District. After a lull in the precipitation later this morning, sleet and/or rain will pick up this afternoon and rain showers will continue from tonight into early Tuesday in the local DC metro region. It'll get milder tomorrow just ahead of the frontal passage and winds will pick up and will also be quite strong tomorrow night and Wednesday post-frontal system. Temperatures will remain below normal from the mid-week time period right into the upcoming weekend.

By the way, how strange is it to be talking about accumulating snow around here after the 15th of March? Since 1990, there have only been two reports at Dulles Airport with an inch or more of snow accumulation after March 15th, none at Reagan National Airport, and only one at BWI Airport.

Video

httpv://youtu.be/iVggd0aSpys

4:50 PM | Winter hangs on for DC, Philly and NYC

Discussion

Another major winter storm will affect the Mid-Atlantic and Northeast US over the next 48 hours or so with snow, sleet and rain in the DC, Philly and New York metro areas and this’ll include possible snow/ice accumulations of a coating to a couple of inches; especially, on grassy surfaces to the north and west of these metro areas and in higher elevation locations. Farther north, this storm will bring another round of significant snow accumulation for much of New England by the time Tuesday evening rolls around.

DC Outlook: Snow is likely to break out late tonight across the DC metro region and it will have an impact on the morning commute as slippery spots are quite possible on untreated surfaces. This snow will then mix with sleet and rain for awhile during the morning hours before changing to plain rain by later in the afternoon. Accumulations of a coating to a couple of inches are possible before the changeover to plain rain; especially, on grassy surfaces to the north and west of the DC metro region and in higher elevation locations. In fact, as with the last big winter storm to affect the DC area, the greatest accumulating snow in this general vicinity will likely occur in western Virginia and eastern West Virginia. Rain will continue tonight into early Tuesday in the DC metro region and some of it can fall heavily at times.

By the way, how strange is it to be talking about accumulating snow around DC after the 15th of March? Since 1990, there have only been two reports at Dulles Airport with an inch or more of snow accumulation after March 15th, none at Reagan National Airport, and only one at BWI Airport.

Philly Outlook: Snow is likely to break out during the mid-to-late morning hours across the Philly metro region and it could be mixed with sleet and/or rain. Gradually, the precipitation will changeover over to plain rain by later in the day or early tomorrow night. Accumulations of a coating to a couple of inches are possible before the changeover to plain rain; especially, on grassy surfaces to the north and west of the Philly metro region and in higher elevation locations. Rain will continue from later tonight into Tuesday in the Philly metro region and some of it can fall heavily at times.

New York City Outlook: Snow, sleet and rain is likely to break out during the mid-to-late afternoon hours across the NYC metro region and it will continue into the evening. Gradually, the precipitation will changeover over to plain rain by later tonight and the rain will continue on Tuesday. Accumulations of a coating to a couple of inches are possible before the changeover to plain rain; especially, on grassy surfaces to the north and west of the NYC metro region and in higher elevation locations.

1:45 PM | Snow will resume later today across SE PA; next threat for snow comes late Sunday night/early Monday across SE PA and possibly as far south as the DC metro region

Discussion

There is a lull in the action right now across SE PA with respect to today’s precipitation event, but heavy snow bands exist upstream across south-central PA and occasional snow will resume later this afternoon possibly mixed with sleet at times. Snow accumulations are likely from today’s fast-moving low pressure system across SE PA; especially, on grassy surfaces and in higher elevation locations, and some of the snow will may come down quite hard for a brief time. Another snow threat exists for SE PA early Monday as the next system in this active weather pattern approaches the region from the southwest. Furthermore, while today’s system is producing only rain in the DC metro region, this next system could produce snow as far south as DC come late Sunday night/early Monday at the onset of the next precipitation event. Eventually milder air will cause a changeover of the snow to sleet and then to plain rain later Monday and the rain will likely fall quite heavily at times from Monday night into early Tuesday as a strong cold front plows towards the east coast. That cold front will usher in more cold air for the Mid-Atlantic region and the remainder of the month of March continues to look quite a bit colder-than-normal with no sustained spring weather in sight.

2:50 PM | I'll bet the groundhog is hiding

Discussion

What a difference a year makes! Last March, the temperatures in Philadelphia ended up a whopping 8.7 degrees above normal whereas this year, the monthly temperatures are almost certain to end up below normal thanks to a colder-than-normal second half. No change today in the colder-than-normal outlook for the second half of March in the Mid-Atlantic region. In fact, all of the latest information confirms this longer-term outlook with an especially “nasty-looking” cold during the last ten days of the month. On the precipitation side of things, it does look like an active and fast-moving overall weather pattern for the next couple of weeks with numerous systems to deal with in the Mid-Atlantic.

The first system that will affect us is currently dropping southeastward across the Northern Plains and it will spread precipitation into the region early Saturday. While plain rain is likely in and around the DC metro region on Saturday, it should be just cold enough for some snow and sleet north of the PA/MD border, and there can even be some snow accumulations across SE PA, central NJ, and points northeastward to the NYC metro region; especially, on grassy surfaces and in higher elevation locations. After a short break on Sunday, a second system will approach the I-95 corridor from the southwest by early Monday and it should be just cold enough again in the morning hours on Monday for some more snow and sleet in parts of the Mid-Atlantic such as SE PA before milder air moves in and changes all of the precipitation to plain rain for the period from later Monday afternoon into Tuesday. In fact, some of the rain can actually become quite heavy Monday night/early Tuesday ahead of a strong cold front which will usher in cold air for the middle and latter parts of next week – setting the stage for some “nasty” cold during the last ten days of March in the Mid-Atlantic.