10:25 AM | *Snow late tonight/early Monday for DC, Philly metro regions…event can result in 3 or 4 inches at the Jersey Shore*
Paul Dorian
A potent wave of energy in the upper atmosphere near the Mid-Atlantic coastline come early Monday afternoon (shown in blue on 500 mb height anomaly 12Z GEFS forecast map); map courtesy tropicaltidbits.com, NOAA/EMC
A colder pattern has become firmly established and now there is likely to be some accumulating snow in the DC and Philly metro regions during the late night and early morning hours. The NYC metro region is likely to be on the very northwest edge of the expected snow field. The greatest potential for a few inches of snow looks like it’ll be over the Delmarva Peninsula and the southern half of New Jersey where up to 3 or 4 inches are possible by later Monday morning at places like the Jersey Shore (e.g., Cape May). A potent wave in the upper atmosphere will set off the development of a surface wave of low pressure overnight and this system will likely bring the snow to much of the region late tonight and early Monday.
12Z GFS surface forecast map for early Monday; map courtesy tropicatidbits.com, NOAA/EMC
The evening will start off on the quiet side, but then an area of low pressure will develop to our southwest this evening and strengthen overnight across the Delmarva as potent energy in the upper atmosphere phases in with the surface system. This area of low pressure will then push offshore during Monday morning and winds will pick up out of the NW with a residual snow shower possible during the PM hours. Temperatures should be cold enough for all snow during this event in the DC-to-Philly-to-NYC corridor and even down to the NJ coastline. Accumulations by later Monday morning should be on the order of a coating to an inch or two in the DC and Philly metro regions; 2-4 inches likely across the Delmarva Peninsula and southern/central NJ, and a coating is possible in and around the immediate NYC vicinity. Another system will likely affect parts of the Mid-Atlantic region on Tuesday with snow shower activity; especially, north of the PA/MD border and then another "clipper" is possible on Wednesday. Looking farther ahead, there are early signs for a possible Super Bowl Sunday (and Monday) storm in the Mid-Atlantic region, but that is still many days away.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com