Vencore Weather
25Nov/14Tue

1:00 PM | **An update on tomorrow’s first significant snow event of the season**

NAM_snowfall
[High-resolution snowfall estimate forecast map from NAM model; courtesy NOAA]

Discussion

Overview
All systems go for the first significant snow event of the season in much of the Mid-Atlantic region. Snowfall estimates (see below) in the region from DC-to-Philly-to-NYC have not changed with the latest model guidance; however, the timing of the event has speeded up by a couple of hours. As a result, the precipitation will likely begin in the pre-dawn hours in many areas along the I-95 region between DC and Philly and will end in all locations a bit sooner tomorrow evening.

Details
Low pressure is developing today over the eastern Gulf of Mexico and it will intensify rapidly on Wednesday as it tracks quickly northeastward along the east coast. The low is expected to pass just east of Long Island on Wednesday evening before reaching Nova Scotia by Thursday morning. This storm will have a big impact on the interior Mid-Atlantic region on Wednesday with more snow to the north and west and less to the south and east. The map (above) shows snowfall estimates from the high-resolution version of the NAM computer forecast model and it clearly shows the higher amounts to the north and west and the lesser amounts to the south and east. The rain/snow line will be dropping from the northwest to the southeast tomorrow morning in the region near I-95. Precipitation will likely be in the form of all snow by early afternoon along I-95 and points to the north and west. Sleet can get involved as well on Wednesday during the transition period from rain to snow. Elevation will also play an important role with higher elevation locations to the north and west changing quicker to snow compared with nearby lower elevation locations.

Travel
As far as travel is concerned, precipitation from this coastal storm will begin in the pre-dawn hours in many locations so “beating it” will be somewhat difficult given its quick movement. However, there will be a time period during the initial changeover to snow in which the snow will melt on the roadways given the warmth of recent days. In general, the worst driving conditions are likely to occur from the mid-day hours through the afternoon and then into the early evening before winding down. The snow will wind down from southwest-to-northeast later tomorrow (late afternoon in DC, early evening in Philly, late evening in NYC).

Summary of snowfall estimates

DC area:
1-3 inches in and around the District
3-6 inches in the N and W suburbs
Coating-1 inch just S and E of the District

Philly area:
2-4 inches in and around Philly
4-8 inches in the N and W suburbs
Coating-2 inches at the Jersey Shore

NYC area:
3-6 inches in and around the NYC metro region
6-10 inches in the N and W suburbs
2-4 inches across Long Island

wv
[Water vapor image showing lots of moisture along the east coast; courtesy NOAA]

Filed under: NYC, PHL, WMA Comments Off
25Nov/14Tue

7:00 AM | **First significant snow of the season on Wednesday**

6-Day Forecast

Today

Partly sunny, cooler than yesterday, highs in the mid 50’s

Tonight

Mostly cloudy, turning colder late, lows in the upper 30’s by morning

Wednesday

Rain developing in the morning, changing to snow from northwest-to-southeast during the afternoon hours, breezy, noticeably colder, highs near 40 degrees

Wednesday Night

Snow likely before midnight, breezy, cold, total accumulations by morning of 3-6 inches in and around the NYC metro region, 6-10 inches in the northern and western suburbs, 2-4 inches across western and central Long Island, lows near 30 degrees

Thursday

Mostly cloudy, a bit of a breeze, cold, maybe a snow shower or two, near 40 degrees

Friday

Mostly sunny, cold, mid-to-upper 30’s

Saturday

Partly sunny, still cold, near 40 degrees

Sunday

Partly sunny, milder, upper 40's

Discussion

The first significant snowfall of the season is on the way for the NYC metro area and much of the Mid-Atlantic region. Low pressure will develop over the eastern Gulf of Mexico later today and intensify as it tracks northeastward along the east coast on Wednesday. The low is expected to pass just east of New Jersey on Wednesday evening before reaching the New England coastal waters late Wednesday night. This coastal storm will have a big impact on the interior Mid-Atlantic region on Wednesday and Wednesday night resulting in rather typical fashion in this region of generating more snow to the north and west and less snow to the south and east.

Precipitation should overspread the region from the southwest around dawn. Precipitation should start off as rain or a mixture of rain and snow before changing to all snow from northwest-to-southeast during the afternoon hours. Snow is likely for most, or all, of the storm in places well to the northwest of here such as in the Hudson Valley region. The last area to change over to snow will be over Long Island and they can expect less snowfall (2-4 inches in western and central sections). Northerly winds are forecast to increase to 10 to 20 mph on Wednesday with gusts to 25 or 30 mph possible. The snow will be of the heavy, wet variety.

As far as road conditions are concerned, initially the snow will have trouble sticking thanks to the recent round of warm weather. The worst driving conditions are likely to occur during the late afternoon and especially tomorrow evening when the effectiveness of the sun diminishes and temperatures drop to near freezing. One other note, looking ahead, signs point to a break in the weather pattern as we begin December with above-normal temperatures quite likely for awhile.

Video

Filed under: NYC Comments Off
25Nov/14Tue

7:00 AM | **First significant snow of the season on Wednesday**

6-Day Forecast

Today

Mostly cloudy, cooler than yesterday, highs in the mid 50’s

Tonight

Mostly cloudy, turning colder late, chance for rain or a mixture of rain and snow towards morning, lows in the mid-to-upper 30’s

Wednesday

Rain or a mixture of precipitation in the morning should change to snow from northwest-to-southeast during the mid-day and afternoon hours, noticeably colder, highs in the upper 30's

Wednesday Night

Snow ending during the evening, breezy, cold, total accumulations of 1-3 inches in and around the District, 3-6 inches in the northern and western suburbs, a coating to an inch in areas just to the south and east of DC, lows in the upper 20's

Thursday

Mostly cloudy, breezy, cold, a few morning snow showers likely, near 40 degrees

Friday

Mostly sunny, cold, mid-to-upper 30’s

Saturday

Partly sunny, still cold, low 40’s

Sunday

Partly sunny, milder, mid 50’s

Discussion

The first significant snowfall of the season is on the way for the DC metro area and much of the Mid-Atlantic region. Low pressure will develop over the eastern Gulf of Mexico later today and intensify as it tracks northeastward along the east coast on Wednesday. The low is expected to pass just east of New Jersey on Wednesday evening before reaching the New England coastal waters late Wednesday night. This coastal storm will have a big impact on the interior Mid-Atlantic region on Wednesday and Wednesday night resulting in rather typical fashion in this region of generating more snow to the north and west and less snow to the south and east.

Precipitation should overspread the region from the southwest before dawn. Precipitation should start off as rain or a mixture of rain and snow before changing to all snow from northwest-to-southeast during the mid-day and afternoon hours. The last area to change over to snow will be down at the Eastern Shore and they can expect the least amount of snow (coating to an inch). Northerly winds are forecast to increase to 10 to 20 mph on Wednesday with gusts to 25 or 30 mph possible. The snow will be of the heavy, wet variety.

As far as road conditions are concerned, initially the snow will have trouble sticking thanks to the recent round of warm weather. The worst driving conditions are likely to occur during the late afternoon and early evening hours when the effectiveness of the sun diminishes (yes, even on a cloudy day) and temperatures drop to near freezing. A couple of other notes, yesterday was indeed a record-breaker at DCA with a high of 74 degrees. Also, looking ahead, signs point to a break in the weather pattern as we begin December with above-normal temperatures quite likely for awhile.

Video

Filed under: WMA Comments Off
25Nov/14Tue

7:00 AM | **First significant snow of the season on Wednesday**

6-Day Forecast

Today

Mostly cloudy, cooler than yesterday, highs in the mid 50’s

Tonight

Cloudy, turning colder late, chance for rain towards morning, lows in the mid 30’s

Wednesday

Rain or a mixture of precipitation in the morning should change to snow during the mid-day and afternoon hours from northwest-to-southeast, noticeably colder, highs in the upper 30's

Wednesday Night

Snow ending before midnight, cold, total accumulations by morning of 2-4 inches in and around Philly, 4-8 inches in the northern and western suburbs, a coating to 2 inches at the Jersey Shore, lows in the upper 20's

Thursday

Mostly cloudy, breezy, cold, a few morning snow showers possible, upper 30’s

Friday

Mostly sunny, cold, mid-to-upper 30’s

Saturday

Partly sunny, still cold, low 40's

Sunday

Partly sunny, milder, low 50's

Discussion

The first significant snowfall of the season is on the way for the Philly metro area and much of the Mid-Atlantic region. Low pressure will develop over the eastern Gulf of Mexico later today and intensify as it tracks northeastward along the east coast on Wednesday. The low is expected to pass just east of New Jersey on Wednesday evening before reaching the New England coastal waters late Wednesday night. This coastal storm will have a big impact on the interior Mid-Atlantic region on Wednesday and Wednesday night resulting in rather typical fashion in this region of generating more snow to the north and west and less snow to the south and east.

Precipitation should overspread the region from the southwest towards morning. Precipitation should start off as rain or a mixture of rain and snow before changing to all snow from northwest-to-southeast during the mid-day and afternoon hours. Snow is likely for most, or all, of the storm in places well to the northwest of here such as the Poconos, Lehigh Valley and Berks County. The last area to change over to snow will be down at the Jersey Shore and they can expect the least amount of snow (coating to 2 inches). Northerly winds are forecast to increase to 10 to 20 mph on Wednesday with gusts to 25 or 30 mph possible. The snow will be of the heavy, wet variety.

As far as road conditions are concerned, initially the snow will have trouble sticking thanks to the recent round of warm weather. The worst driving conditions are likely to occur during the late afternoon and evening hours when the effectiveness of the sun diminishes and temperatures drop to near freezing. A couple of other notes, yesterday was indeed a record-breaker at PHL with a high of 72 degrees. Also, looking ahead, signs point to a break in the weather pattern as we begin December with above-normal temperatures quite likely for awhile.

Video

Filed under: PHL Comments Off