1:30 PM (Tuesday) | ***A changeover to snow around or shortly after midnight…continues into early Wednesday...watch for black ice**
Paul Dorian
Around or shortly after midnight it should get just cold enough for a changeover to snow in the immediate I-95 corridor region; map courtesy NOAA, tropicaltidbits.com
Overview
A slow-moving cold front will push across the region later this afternoon and temperatures will fall through the evening hours. Showers ahead of the front will continue through the afternoon in the I-95 corridor and then enough cold air will filter into the region for a changeover to snow around or shortly after midnight. The snow will then continue into early Wednesday with some accumulations along the I-95 corridor on the order of a coating (urban areas) to 2 or 3 inches (northern/western suburbs). The snow will have a much more difficult time sticking to the asphalt roadways during this event after today’s warmth as compared with grassy surfaces, but that raises the chances for black ice during the morning commute as temperatures will be near freezing.
Snow is forecasted by the 12Z GFS for the I-95 corridor at 7AM Wednesday (shown in blue); map courtesy NOAA, tropicaltidbits.com
Discussion
Ahead of a strong and slowly moving cold front, temperatures in the DC-to-Philly-to-NYC corridor have climbed to well up in the 50’s, but they’ll start to drop later in the afternoon following the passage of the front. Rain has returned to much of the Mid-Atlantic region and it’ll continue through the afternoon, but it could actually slacken off or end for a brief time this evening. A second area of moisture will then push back into the region later this evening as temperatures drop into the 30’s. Around or shortly after midnight, it should get cold enough for a changeover to snow from northwest-to-southeast and that snow should continue into the morning hours along the DC-to-Philly-to-DC corridor. Accumulations are likely to average out in the range of a coating to two or three inches with the lower amounts in the urban areas and the higher amounts in the northern and western suburbs. In addition, the snow will have a much more difficult time sticking to the asphalt roadways during this event after today’s warmth as compared with grassy surfaces, but that raises the chances for black ice during the morning commute as temperatures will be near freezing.
Mid-day radar shows an area of precipitation in the Lower Mississippi Valley that is behind the surface cold front and this is the area that will push to the northeast overnight and result in some snow for DC, Philly, NYC; map courtesy WSI, Inc., intellicast.com, NOAA
As the precipitation winds down later Wednesday morning, the snow could mix with some rain and then the afternoon should feature some clearing skies, but the cold conditions will remain. In fact, the cold air really moves in full force tomorrow night with overnight lows near the 20 degree mark in much of the DC-to-Philly-to-NYC corridor and highs on Thursday will be held in the low-to-mid 30’s in most areas.
Looking ahead, there is the chance for a significant rain event on Friday night and then another storm is on the horizon for next Monday night or Tuesday and this one could have some cold air to work with - stay tuned.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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