2:30 PM | Record cold in Alaska AND Florida with half the country covered by snow

Discussion

Anyone who happened to watch a spring training game from Florida yesterday probably noticed the fans bundled up in winter coats as afternoon temperatures were generally in the 50’s along with a strong northerly wind at 25-30 mph throughout much of the state. Indeed, there was record-breaking cold yesterday in much of the Deep South from Texas to Florida. In fact, the following numerous Floridian cities either broke or tied their record low temperatures during the past 24 hours: Key West, Eglin, Cocoa Beach, Titusville and Lakeland. And, in what has to be a pretty rare coincidence, there was also record-breaking cold in Alaska at the same time as in the Deep South with the following numerous Alaskan cities either breaking or matching their daily record low temperatures: Fairbanks, Minchumina, Kake, Wainwright, Wasilla, Kenai and Homer. All in all, quite an impressive and expansive cold air outbreak for late March. Also, snow cover on March 25th covered about 48 percent of the country compared to 8 percent one year ago.

7:00 AM | Milder this weekend, but rain will threaten by later Easter Sunday

6-Day Forecast

Today

Sunshine this morning, clouds this afternoon, breezy, chilly, chance for a couple of rain showers, highs near 50 degrees

Tonight

Mostly cloudy, cold, chance for an evening shower, lows in the low 30's

Thursday

Partly sunny, still chilly, slight chance for a rain shower, near 50

Thursday Night

Partly cloudy, cold, low 30’s

Friday

Partly sunny, cool, low 50’s

Saturday

Partly sunny, a bit milder, mid 50’s

Sunday

Increasing clouds, mild, rain possible during the afternoon and at night, low 60's

Monday

Mostly cloudy, mild, showers likely, upper 50’s

Discussion

Low pressure in the upper atmosphere will continue to keep the weather a little unsettled today with the chance for a couple of afternoon rain showers. High pressure will gradually build into the region late this week and a warming trend will finally boost temperatures to seasonal levels over the weekend. However, clouds will increase on Sunday and rain will threaten by later in the afternoon or evening and the threat will continue on Monday as a cold front moves towards the East. Colder air will return by Tuesday behind this next cold frontal system as the below normal temperature pattern continues for awhile longer.

Video

httpv://youtu.be/oNfQzOre7Pk

7:00 AM | Still somewhat unsettled and on the chilly side, but weekend looks pretty seasonal

6-Day Forecast

Today

Mostly cloudy, chilly, chance for a couple of rain or snow showers, highs in the mid-to-upper 40’s

Tonight

Mostly cloudy, cold, chance for a rain or snow shower, lows in the low 30’s

Wednesday

More clouds than sun, still chilly with the chance for a rain or snow shower, upper 40’s

Wednesday Night

Mostly cloudy, cold, maybe a snow shower, low 30’s

Thursday

Partly sunny, chilly, upper 40’s

Friday

Partly sunny, a bit milder, low 50’s

Saturday

Mostly sunny, milder, low-to-mid 50’s

Sunday

Increasing clouds, even milder, chance for showers late or at night, upper 50’s

Discussion

In the wake of yesterday’s snow event, the atmosphere will remain quite unsettled for the next few days and rain or snow showers can occur at just about any time, but much of the time will be precipitation-free. Temperatures will remain below normal for this time of year generally holding in the 40's for the next few days (normal high is now 59 at Reagan National Airport). More seasonal temperatures are possible by the weekend as weak high pressure moves into the region, but another cold shot is likely to move in early next week in this continuing chilly early spring weather pattern.

Video

httpv://youtu.be/809dTnOZXkE

12:30 PM | Snow not quite done with yet; especially, across portions of New Jersey

Discussion

While the snow has lightened up in some parts of the Mid-Atlantic, this “March Madness” snow is not quite over with yet. In fact, the coastal low is intensifying rapidly and snow has resumed in the DC metro region after having stopped during the mid-morning hours. An expansion of the radar loop in the DC region is tied in with the upper level dynamics just now entering the picture in the Mid-Atlantic region. Snow is likely to continue into the evening hours at varying intensities throughout much of the Mid-Atlantic region between DC and NYC. The snow will also mix with rain at times; especially, when it lightens up, and the roads will simply be wet during the afternoon hours. However, slick conditions could return overnight on untreated road surfaces as temperatures will drop to slightly below freezing. The highest snowfall amounts may end up in the interior sections of central and southern New Jersey with 6+ inches possible in spots as the coastal low starts to really crank and generates heavy banding near the coast later today. Snow has already reached 3+ inches in many suburban Philly locations (e.g. 4.5 Glenmore, PA, 4.5 East Nantmeal, PA, 3.8 Royersford, PA, 3.2 Wayne, PA, 3.2 Gilbertsville, PA, 3.0 Exton, PA) and while more small accumulations are possible, there will be some melting as well given the high sun angle this time of year.

Elsewhere, the immediate DC and Baltimore metro regions have already received 1-3 inches of snow with 3-6 inches in some of their northern and western suburbs (e.g. 3.8 Chantilly, VA, 4.0 Leesburg, VA, 3.2 Lorton, VA, 3.5 Chevy Chase, MD, 5.0 Parksville, MD, 5.4 Columbia, MD). Reagan National Airport (DC) has actually already recorded their highest snowfall amount since January 2011 with an inch and a half; BWI was at 2.1 inches as of late morning. Philly Airport needs to exceed 2.3 inches to make this their biggest snowfall in two years. The snow will increase in intensity in the NYC metro during the late afternoon and early evening hours, but those areas north of Long Island, NY will likely not receive any significant precipitation from this storm.

Finally, Opening Day is only a week away.

7:00 AM | **Monday Mid-Atlantic snowstorm**

6-Day Forecast

Today

Snow, mixed with sleet and rain at times, breezy, cold, 3-6 inches in the northern and western suburbs outside the beltway with 1-3 inches in the District and points to the south and east, temperatures holding generally in the mid-to-upper 30’s

Tonight

Snow or a mixture of snow, sleet and rain winds down this evening, windy, cold, lows near 30 degrees

Tuesday

Mostly cloudy, still breezy and cold, mid 40’s

Tuesday Night

Partly cloudy, cold, near 30

Wednesday

Partly sunny, cold, mid-to-upper 40’s

Thursday

Mostly sunny, cold, upper 40’s

Friday

Partly sunny, chilly, near 50

Saturday

Partly sunny, chilly, near 50

Discussion

A major springtime snow event is underway in the Mid-Atlantic region and it could turn out to be the biggest snowstorm in a couple of years around here. A strong storm is intensifying along the Mid-Atlantic coast this morning as energy transfers from a weakening primary low over the Ohio Valley. As a result, snow will fall heavily at times today, possibly mixed with sleet and rain on occasion and the winds will intensify as the day progresses. Accumulations of heavy, wet snow should pile up today and early tonight in the northern and western suburbs (outside the beltway) on the order of 3-6 inches, and 1-3 inches are likely in the District and areas to the south and east. The combination of the heavy, wet snow and increasing NE winds could cause some power outages throughout the Mid-Atlantic region from this coastal storm by late tonight. Once this storm passes by late tonight, the bulk of the week will remain colder-than-normal and on the dry side.

Video

httpv://youtu.be/y73bk5pyLP8

1:15 PM | **March Madness continues tonight and Monday with a springtime Mid-Atlantic snowstorm**

Discussion

March Madness continues in the Mid-Atlantic on Monday with a springtime snowstorm and perhaps the biggest snow event in a couple of years around here. A major coastal storm will affect the Mid-Atlantic region from tonight into early tomorrow night and significant snow accumulations are likely. Heavy snow is falling today across parts of the Midwest as one low pressure system heads towards the Ohio Valley. Meanwhile, heavy rain and thunderstorms have broken out across the Southeast US as a secondary low pressure system begins to take shape near the coastline. By tomorrow, the Ohio Valley primary low will begin to weaken as the secondary takes over near the Mid-Atlantic coast. This storm will then intensify rapidly on Monday as it slowly pulls to the northeast.

Precipitation should move into the DC region early this evening, then late this evening across Philly, and finally by very late tonight in the NYC metro region. The precipitation could start as rain or a mix of rain, sleet and snow at the onset, but should change to all snow fairly quickly; especially, in the northern and western suburbs of these three metro regions. The first wave of precipitation from this storm will come from the Ohio Valley primary low and then the coastal low takes over on Monday. In fact, the snow is likely to come down quite hard during the period from mid-morning to mid-afternoon on Monday after the coastal low takes over and the upper level dynamics reach their peak, and there is likely to be some disruptive effects on travel conditions. The snow can mix with sleet and rain at times on Monday; especially, during the afternoon hours in the big cities. The snow will be of the wet and heavy variety and the combination of the heavy, wet snow and intensifying northeasterly winds could lead to some power outages anywhere from Long Island to the Delmarva Peninsula. The storm does not look like it will ride up the New England coastline so Boston and Portland will likely be spared from any significant precipitation.

Preliminary snowfall accumulation estimates for the entire storm are as follows: 1-3 inches in the immediate DC, Philly and NYC metro regions and points south and east all the way to the coastline; 3-6 inches in the northern and western suburbs (outside the beltway in the DC metro region; Chester, Bucks, Montgomery Counties in the Philly area; northwestern NJ, Lower Hudson Valley near NYC).

Video

httpv://youtu.be/6bm4dDTbe4U

2:30 PM | *Snow accumulations on Monday in the N and W suburbs of DC, Philly, NYC*

Discussion

All systems are go for a significant coastal storm to affect the Mid-Atlantic region during the period of late Sunday to late Monday and snow accumulations are likely, perhaps even several inches on grassy surfaces; especially, in the N and W suburbs of DC, Philly and NYC. A strong storm, supported by a powerful upper level jet streak, is currently dumping heavy snow across the southern Rockies (e.g., 6-12 inches in Denver) and it will continue to cross the country this weekend. By later tomorrow, this “primary” low will grind to a halt over the Ohio Valley as it encounters the atmospheric roadblock that we’ve been talking about in recent days, and at this point it will transfer its energy to a developing “secondary” low near the Mid-Atlantic coastline. Precipitation will move into the Mid-Atlantic region late Sunday and come down hard for much of the day on Monday. All regions along the I-95 corridor from DC-to-Philly-to-NYC will likely see a mixed bag of precipitation at the onset of this event, but a changeover to primarily snow will occur in the N and W suburbs of these metro areas by later Sunday night or early Monday. The mixed precipitation is likely to hold on for a longer time in the immediate metro regions and to nearby locations to their south and east. Stay tuned.

2:30 PM | *Storm threat continues for late Sunday and Monday with significant snow accumulations still on the table for N and W suburbs*

Discussion

All of the latest indications continue to point to accumulating snow in the northern and western suburbs of the I-95 corridor cities of DC, Philly and NYC early next week with several inches of accumulation on the table. Even the big cities can end up with important snow accumulations from this storm, but there may be an extended period of mixed precipitation before a changeover to all snow in those areas.

A major storm will cross the country this weekend generating heavy snow from Denver to St. Louis and by later Sunday, it’ll run into an atmospheric roadblock over the Ohio Valley forcing it to grind to a screeching halt. At this time, energy will transfer from the initial “primary” low to a “secondary” low just off the Mid-Atlantic coastline. This coastal storm will then gradually intensify as it moves east-northeast from later Monday into Tuesday.

The approximate timetable for this storm in the Mid-Atlantic I-95 region is late Sunday into late Monday. Precipitation is likely to move into the DC metro region during the early evening hours on Sunday, and then reach the Philly area in the overnight hours and NYC by Monday morning. While the initial precipitation can be a brief mix of rain, sleet and snow in the northern and western suburbs of these cities, it should change to all snow in those locations and significant accumulations are possible. In the big cities and to places just to their east, accumulating snow is possible, but there will likely be an extended period of mixed precipitation during the storm. The northward extent of the significant precipitation shield with this storm may not go much past New York City given the blocking pattern in the upper atmosphere across eastern Canada. In fact, at this time it does not appear that places up the coastline such as Boston or Portland will get any significant precipitation from this storm.

Stay tuned to thesiweather.com this weekend for updates as this event is still a few days away. While it’s not saying much, this could be the biggest snowfall of the winter season in parts of the Mid-Atlantic and the Monday morning commute may be adversely affected.

7:00 AM | *Coastal storm to affect the region later Sunday into Monday*

6-Day Forecast

Today

Partly sunny, breezy, cold, highs in the upper 40’s

Tonight

Partly cloudy, cold, lows in the low 30’s

Saturday

Mostly sunny, still breezy and cold, upper 40’s

Saturday Night

Mostly clear, cold, near 30

Sunday

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

Monday

Cloudy, cold, snow likely with some accumulations, possibly mixed with rain at times, near 40

Tuesday

Partly sunny, cold, mid-to-upper 40’s

Wednesday

Partly sunny, cold, upper 40’s

Discussion

Temperatures will stay below normal in the Mid-Atlantic as we head into the weekend and attention will shift to a storm that will cross the country dumping heavy snow in its path. By Sunday, a “primary” low pressure system will head towards the Ohio Valley after dumping heavy snow on the southern Rockies and central Plains, but as a result of the atmospheric roadblock that this system will encounter, the low will grind to a halt and transfer its energy to a developing “secondary” Mid-Atlantic coastal low. That coastal low will spread precipitation into the I-95 corridor from DC-to-Philly-to-NYC later Sunday into Monday and, while some of it will likely be in the form of rain, accumulating snow is also a real threat given this type of pattern; especially, in the northern and western suburbs and in higher elevation locations. The blocking pattern across Canada may prevent the coastal low from riding up the New England coastline so, as of now, significant precipitation is more of a threat for DC, Philly and NYC as compared to Boston and Portland (but still some time for that to change).

Video

httpv://youtu.be/y4HHy9XVfqg

2:30 PM | Meteorological March Madness: accumulating snow threat continues for the interior Mid-Atlantic early next week

Discussion

An “omega” blocking pattern in the upper atmosphere across Canada will play a major role in the unfolding scenario for early next week. One climate index that we follow that gives an indication as to the strength of the blocking pattern is the Arctic Oscillation (AO). The AO index measures the difference in relative pressures between the Arctic and mid-latitudes and it plummeted yesterday to historically low values (-5.6) and it may even break a record with today’s reading.

Looking ahead to early next week, a “primary” low pressure system will head towards the Ohio Valley on Sunday after dumping heavy snow on the southern Rockies and central Plains, but as a result of the atmospheric roadblock that this system will encounter, the low will grind to a halt and transfer its energy to a developing “secondary” Mid-Atlantic coastal low. That coastal low will spread precipitation into the I-95 corridor from DC-to-Philly-to-NYC later Sunday into Monday and, while some of it will likely be in the form of rain, accumulating snow is also a real threat given this type of pattern; especially, in the northern and western suburbs and in higher elevation locations. Yesterday, we suggested the possibility that the GFS model run would shift somewhat in its forecast for the northward extent of the "primary" low pressure system and indeed the latest 12Z model run has made a change from 24 hours ago. The “primary” low is now forecasted to reach only as far north as West Virginia as compared to the previously somewhat unrealistic location way up in northwestern Pennsylvania. This seemingly subtle shift makes an important difference in parts of the Mid-Atlantic with respect to precipitation type as it yields a slightly colder solution which is critical given the expected marginally cold conditions. The blocking pattern across Canada may prevent the coastal low from riding up the New England coastline so, as of now, significant precipitation is more of a threat for DC, Philly and NYC as compared to Boston and Portland (but still some time for that kind of detail to change).

On another note, for those interested in viewing the cherry blossoms in DC, given the expected continuing cold pattern, it looks like the peak may not occur until the 1st week of April. Last year, the peak occurred around March 20th in a month that was far different than this year and much warmer than normal.

Finally, here are some interesting snowfall amounts for this winter season (up till now) for many cities with New England leading the way:

Worcester, MA 108.9” Portland, ME 97.8” Syracuse, NY 96.5” Erie, PA 94.1" Gray, ME 92.3” Concord, NH 83.2” Deluth, MN 78.3" Flagstaff, AZ 68.3" Madison, WI 66.9" Binghamton, NY 66.5” Bridgeport, CT 64.3” Boston, MA 63.1” Hartford, CT 56.9” Buffalo, NY 55.6" Denver, CO 46.9" Islip, LI NY 46.5” Providence, RI 46.3” Scranton, PA 33.6” Chicago, IL (O'hare) 29.9" Newark, NJ 29.5” Central Park, NY 26.1” JFK Airport, NY 17.6” Atlantic City, NJ 12.3" Philly Airport, PA 7.2” BWI Airport, MD 4.8" Reagan National, DC 1.7”