DC metro region
A wintry mix of snow, sleet and rain is likely to arrive in the DC metro region around 4 or 5 pm moving from southwest-to-northeast. With the cold, dry air mass in place, there can be “evaporative cooling” at the onset of the precipitation which could result in a quick drop in temperatures of a few degrees and this could result in a changeover from mixed precipitation to all snow for awhile throughout the DC metro region. In fact, there is the chance for a burst of heavier snow by early tonight which can quickly cause poor visibility and slick spots on roadways. The chances for snow in the DC metro region will diminish later tonight, but there can be sleet and freezing rain at times; especially, in areas to the north and west of the District which can cause additional slick spots on untreated surfaces. Precipitation winds down Tuesday morning in the form of freezing rain early in the AM and plain rain later in the morning. Accumulations of anywhere from a coating to as much 3 inches or so are possible during this event given the threat of a burst of heavier snow…watch for slick spots during any snow bursts this evening and also late tonight/early Tuesday with the likelihood of freezing rain and/or sleet.
Philly metro region
The push to the north and east of the moisture field with this system will be inhibited by the dense dry air mass that is entrenched across the northern Mid-Atlantic. As a result, snow may not arrive in the southeastern part of PA until late this evening and it could take an unusually long time for it to move from southern Chester County (late evening arrival) to Bucks County (after midnight arrival). Occasional light snow, sleet and freezing rain will continue from late tonight through tomorrow night and there can be slick spots on untreated surfaces and accumulations of a coating to an inch or two.
New York City region
The dense dry air mass in pace across the NE US will help to push off the arrival of the precipitation until tomorrow morning in the NYC metro region. There will be occasional light snow, sleet and freezing rain on Tuesday and Tuesday night and even into the early morning hours of Wednesday with slick spots possible on untreated surfaces and accumulations of a coating to an inch or so are possible.