Friday, 12:55 PM | ***First accumulating snow of the season for DC, Philly, NYC***
Paul Dorian
12Z GFS forecast map for 1pm on Saturday with snow (in blue) throughout the I-95 corridor; map courtesy NOAA/EMC, tropicaltidbits.com
Overview
If you had December 9th in your snow pool, you're looking pretty good right about now. Low pressure will push out of the eastern Gulf region later today and head to a position off the Mid-Atlantic coastline by later tomorrow and the big cities from DC-to-Philly-to-NYC will receive their first accumulating snowfall of the winter season. Snow fell this morning from this same storm system across many southern areas (e.g., Texas, Louisiana) that are not used to seeing much snow; especially, this early in the season.
Discussion
The 12-hour period of concern for the steady snow in the DC-to-Philly-NYC corridor is from around 4 or 5am to 4 or 5pm and accumulations on the order of 2-4 inches are likely in and around the big cities. Just to the east of the big cities, there can be as much as 3-6 inches from late tonight into late tomorrow including across the Delmarva Peninsula and in the interior sections of New Jersey. The snow winds down early tomorrow evening and there can be a few residual snow showers overnight along with stiff winds and below-freezing temperatures.
Wintry conditions across the Deep South early today with snow in Corpus Christi, Texas (left) where it was 82 degrees two days ago and ice/snow combination in New Orleans, Louisiana (right)
Temperatures should be cold enough to support accumulating snow from the big cities and to their north and west (i.e., highs only in the low-to-mid 30’s on Saturday), but they will be somewhat marginal as one moves east and closer to the coastline where grassy accumulations may dominate. Untreated roads will deteriorate early tomorrow shortly after the steadier snow arrives. There can be a couple of snow showers preceding the steadier snow late today and early tonight, but the evening rush hour should be fine for driving.
It stays cold on Sunday and Monday and then the next shot for snow or snow showers will come on late Monday night and Tuesday as a significant cold air outbreak arrives. This next snow threat may be highest across the northern Mid-Atlantic and interior Northeast US as upper-level energy pushes into that part of the country. Temperatures on Wednesday following the next snow threat may not reach the 30 degree mark in places like Philly and NYC.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com
AM video discussion: