12:00 PM | ***Rain-to-snow scenario in the Mid-Atlantic region from later Monday into Tuesday...accumulations are possible; especially, to the north of the PA/MD border***

With colder air to the north and west wrapping into the departing coastal low, precipitation can change to snow across at least some of the DC-to-Philly-to-NYC corridor late Monday night or Tuesday morning and accumulations in some areas are likely. Map courtesy ECMWF, Pivotal Weather

Overview

The next two days will be very mild across the Mid-Atlantic region with highs reaching the upper 50’s in many areas and 60+ degrees in a few spots. A cold front pushes through later Saturday with some rain shower activity, but there will not be any truly cold air mass following it for the beginning of the new week. Later Monday, an intensifying storm system will push towards the Mid-Atlantic region and with no cold air established, rain is likely to fall in the DC-to-Philly-to-NYC corridor. As the storm pushes to the Mid-Atlantic coastline, colder air will wrap into the system from the north and west on Monday night and a changeover to snow is possible all the way down to the I-95 corridor. Accumulations of snow are on the table by early Tuesday; especially, in areas to the north of the PA/MD border.

The next two days will feature well above-normal conditions in the Mid-Atlantic region with some spots crossing the 60 degree mark for afternoon highs. Map courtesy NOAA, tropicaltidbits.com

Details

A couple of very mild days are on the way to the Mid-Atlantic region with temperatures likely peaking at 60+ degrees in, for example, places like Washington, D.C. despite featuring plenty of clouds. A cold front pushes through later tomorrow with some rain shower activity and though it will turn cooler behind it on Sunday, temperatures will remain at relatively mild levels going into the new work week.

On Monday, low pressure will push northeastward out of the Tennessee Valley to around West Virginia and then transfer to a coastal low near the Delmarva Peninsula that intensifies before heading out-to-sea in and east-to-northeast fashion. The speed at which this system intensifies and moves away from the coast is still somewhat uncertain and those factors will play important roles in a potential scenario where rain changes to snow.

With little in the way of cold air established ahead of an incoming stream of moisture, precipitation at the onset of the next storm system later Monday will likely be in the form of rain across the DC-to-Philly-to-NYC corridor. However, colder air is likely to wrap into the system and a changeover to snow is likely in many areas. Map courtesy ECMWF, Pivotal Weather

With little in the way of cold air established upon the arrival of the storm’s large moisture field, rain is likely to break out in the I-95 corridor later Monday, but colder air will be posed just to the north and west. As the storm near the coast intensifies on Monday night, colder air to the north and west will get wrapped into the system and the rain is likely to change to snow in many areas; especially, to the north of the PA/MD border and on the northwestern side of I-95. Accumulations are likely in many areas by early Tuesday and amounts will ultimately depend on the strength and speed of the coastal low. From this vantage point, preliminary snowfall estimates would be a coating to an inch or two in and around DC, a couple to a few inches near Philly, and a few-to-several inches possible in and around the NYC metro region…stay tuned as this weather event is still a few days away. Looking ahead, there may be another snow threat in the Mid-Atlantic region by the end of next week or during the subsequent President’s Day weekend.

Meteorologist Paul Dorian
Arcfield
arcfieldweather.com

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