7:00 AM (Sunday) | ****Accumulating snow in the DC-to-Philly-to-NYC corridor at the front end of an Arctic invasion…several inches on the table…brutal cold to follow****

Overview

The snow can come down heavily in the Mid-Atlantic region from later this afternoon into early tonight and this sample forecast map (00Z HRDPS) shows hefty snowfall rates in an hourly period along the I-95 corridor. Map courtesy NOAA, Weather Bell Analytics

Low pressure over the southeastern US early this morning will intensify as it pushes northeastward to a position off the Mid-Atlantic coastline by early this evening and then to near the New England coast by later tonight. Snow or rain changing to snow will break out today across the DC-to-Philly-to-NYC corridor and several inches is possible by the time the system winds down later this evening. Bitter cold air will follow the snow for much of the week ahead with single digit overnight lows on the table and some spots may even touch the zero-degree mark. A mid-week winter storm will have a southern US focus likely producing accumulating snow and/or ice from Texas-to-northern Florida-to-the Carolina coastline…likely staying to the south and east of the Mid-Atlantic region. A third storm system may ride up the east coast by the end of the week with some snow possible in the Mid-Atlantic region in the late Thursday/early Friday time period.

The total snowfall between today and mid-day Thursday features a swath up across the Mid-Atlantic region from today’s event and a swath across the southern states from a winter storm that hits that part of the nation from Tuesday into Wednesday. Map courtesy NOAA, Weather Bell Analytics

Accumulating snow event on Sunday/Sunday night

An Arctic cold front has slowed down in its progression to the south and east this morning and low pressure is now developing along its boundary zone. This low will continue to intensify as it pushes northeastward today reaching a position near the Virginia coastline by later this afternoon and then to east of New Jersey by this evening. Precipitation is likely to begin during the morning hours in the DC metro region, mid-day to early afternoon in the Philly area, and then NYC metro during the early-to-mid afternoon hours. Precipitation may begin as a rain/snow mix along the immediate I-95 corridor with mainly snow to the north and west and rain to the south and east. As the precipitation intensifies through the afternoon and dynamic and evaporation effects kick in, expect any mixture to change to snow in the I-95 corridor and the snow can come down heavily from later this afternoon into tonight. In fact, during times of heaviest snowfall later in the day, the snow can reach or exceed one inch per hour in some of the heavier snow bands that are likely to develop. The snow winds down from southwest-to-northeast from this evening into the overnight hours along the DC-to-Philly-to-NYC corridor as the low pressure system tracks towards the eastern New England coastline while continuing to intensify.

Th expected snowfall accumulations for the DC, Philly and NYC metro regions follow as well as the starting and ending times of the precipitation:

DC:                 3-6 inches with isolated higher amounts

(mid-morning starting time/early evening ending time)

Philly:            4-8 inches with isolated higher amounts

(mid-day-to-early afternoon starting time/late evening ending time)

(The snow will make for quite an interesting Eagles-Rams playoff game that begins at 3pm).

NYC:               4-8 inches with isolated higher amounts

(early-to-mid-afternoon starting time/late night ending time)

Today’s snow event in the Mid-Atlantic region will be followed by brutally cold condition for much of the week with daytime highs in the teens in many spots along the I-95 corridor and overnight lows way down in single digits. Map courtesy ECMWF, weathermodels.com

The big Arctic chill that follows the snow

Once the snow ends later tonight, the focus of attention will shift to the Arctic chill that pushes into the Mid-Atlantic region and sticks around for much of the week ahead. Temperatures by Monday morning are likely to be in the teens in most areas and they’ll struggle to climb back to the 20-degree mark in the afternoon with much lower wind chill values making it feel even colder than the actual air temperatures. Temperatures on Tuesday and Wednesday are very likely to hold in the teens for highs and overnight lows on Monday night, Tuesday night, and Wednesday night are likely to drop into the 0 to +5 degree range in most locations along the DC-to-Philly-to-NYC corridor…a few spots can bottom out at zero degrees.

In terms of threats of snow after today’s event, there will be a winter storm that forms over the Gulf of Mexico later Tuesday and it is likely to produce accumulating snow and ice way down south from Texas-to-northern Florida-to-the Carolina coastline. Such southern cities as Houston (TX), New Orleans (LA), Tallahassee (FL), and Myrtle Beach (SC) can see some snow and/or ice during this upcoming event...a rarity indeed. It appears that the precipitation shield from this winter storm will stay to the south and east of the Mid-Atlantic region as the Gulf low pushes in an east-to-northeast direction to a position over the western Atlantic Ocean. Later in the week, another storm is likely to develop near or over the southeastern US coastline and it has a better chance of coming farther to the north…potentially bringing some snow to the Mid-Atlantic region in the time period from later Thursday into early Friday.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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