12:15 PM (Wed) | **Watch out for freezing rain next 12-24 hours in the far N and W suburbs of the I-95 big cities…soaking rain event from later tomorrow into early Friday**
Paul Dorian
Temperatures later tonight will be near the freezing mark in many suburban areas to the north and west of the big cities in the DC-to-Philly-to-NYC corridor resulting in the freezing of the rain on some surfaces; map courtesy NOAA, tropicaltidbits.com
Overview
An active weather pattern will result in freezing rain for parts of the Mid-Atlantic region during the next 12-24 hours and heavy rainfall is likely from later tomorrow into early Friday with the potential of flash flooding. A strong cold frontal passage last night has resulted in a dramatic drop in temperatures from yesterday’s unseasonably mild conditions and they will drop quite close to the freezing mark in several of the northern and western suburbs along the I-95 corridor in the overnight hours. Meanwhile, another batch of rain will arrive here from the Tennessee Valley and this combination can result in freezing on some surfaces in these normally colder locations. This same front will push back to the north as a warm front on Thursday and pave the way for a strong low pressure system to generate heavy rainfall from later tomorrow into early Friday.
A powerful jet streak aloft will contribute to strong upward motion in the Mid-Atlantic region later tomorrow and tomorrow night leading to some heavy rainfall; map courtesy NOAA, tropicaltidbits.com
Details
A southward-moving cold front has flipped temperatures quite noticeably from yesterday-to-today and temperatures will bottom out later tonight not far from the freezing mark in some of the northern and western suburbs of DC, Philly and NYC. Meanwhile, another wave of low pressure will push to the northeast from the Tennessee Valley and rain will re-develop around here and there can be freezing on some surfaces later tonight into early Thursday. The best chance for the freezing rain will extend from the far northern and western suburbs of DC to areas north and west of the I-95 corridor in Pennsylvania, NJ and NY.
12Z Euro forecast map for just after midnight tomorrow night depicts some heavy rainfall along and to the east of Route I-95; map courtesy ECMWF, WSI, Inc.
By later tomorrow, the system that came through the region last night as a cold front will turn around and head back to the north as a warm front and temperatures will rebound to levels well above freezing. It is at this time that another low pressure system will pull out of the south-central states and head towards the Mid-Atlantic bringing with it the chance for some heavy rainfall. This low pressure system - likely the strongest of the recent series of low pressure systems - will be supported aloft by a vigorous wave of energy and a strong jet streak. The upper-level trough will take on some “negative” tilt and the Mid-Atlantic region will be positioned in the right entrance region of the jet streak in an area of strong upward motion.
The best chance for heavy rainfall later tomorrow and tomorrow night looks like it may take place along and east of the I-95 corridor. Given the already wet soil conditions, flash flooding may become a real concern with the heavy rainfall perhaps totaling as much as two or three inches in some spots by mid-day Friday. There can even be a few thunderstorms mixed in; especially, over the Delmarva Peninsula and areas south and east of there. In fact, there are some signs that a squall line will form late tomorrow/tomorrow night ahead of a cold front that will extend to the southwest of the low pressure center. Colder air will follow the passage of this cold frontal system on Friday and northwest winds will pick up noticeably in intensity. Also, there is a chance that the rain changes to snow and/or sleet in the Mid-Atlantic region before it winds down on Friday; especially, in areas to the north and west of the I-95 corridor. Over the weekend, a weak wave of energy will head into the eastern states and it may produce a bit of snow in the Mid-Atlantic region, but nothing significant which has been an on-going theme this winter.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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