11:20 AM (Wed) | ****Heavy rain, potential damaging wind gusts tomorrow night into early Friday in Mid-Atl/NE US…power outages on the table…temperatures plunge on Friday as much colder air arrives****

Excessive wind gusts are possible with the passage of this powerful cold front and power outages are on the table in the Mid-Atlantic/NE US from tomorrow night into early Friday. Map courtesy Weather Bell Analytics, NOAA

Overview

A powerful cold front will barrel towards the eastern seaboard from later tomorrow into early Friday and it’ll bring some wild weather to the Mid-Atlantic/Northeast US.  Ahead of the front, heavy rains, possible thunderstorms and potentially damaging winds will develop and raise the prospects for localized flooding and power outages.  It’ll become much milder as well on Thursday with temperatures soaring to the 60 degree mark in the DC, Philly and NYC metro regions. On the back side of the front, temperatures will plunge on Friday from their early morning highs to at or below freezing by later in the afternoon.  Any standing water on untreated surfaces that is left behind by the heavy rain event could freeze-up in a hurry on Friday as temperatures take a plunge.   

The strong cold front will be barreling eastward by later tomorrow night with snow, cold on its back side and heavy rain, potential damaging winds and thunderstorms on its front side. Map courtesy NOAA, tropicaltidbits.com

Details

Christmas Eve (Thursday) is likely to begin with decent snow cover in many areas of the Mid-Atlantic/NE US, but most or all of this will be washed away by the time Christmas morning rolls around; especially, on the east side of the Appalachian Mountains.  Heavy rain is likely from later tomorrow into early Friday - just ahead of and along a powerful cold front - and it’ll turn much milder with temperatures soaring through the 50’s in the DC-to-Philly-to-NYC corridor. 

Rainfall will be heavy on the front side of the advancing cold front with anywhere from 1-3 inches in the Mid-Atlantic/NE US by the time Friday afternoon rolls around. Map courtesy NOAA, tropicaltidbits.com

In addition to the heavy rain and milder conditions, winds will become a very important factor on Thursday night and early Friday with the potential of gusts of 50+ mph across inland locations and 70+ mph along coastal sections.  Winds in the lower part of the atmosphere will reach excessive levels tomorrow night - just ahead of the strong cold front - and it won’t take much in the way of “mixing” to bring these winds down to surface levels. In fact, one of the mechanisms that can result in damaging wind gusts will be strong thunderstorm activity that is likely to develop along the frontal system from later tomorrow into the early morning hours on Friday.  Unfortunately, these kind of gusts will raise the chances for power outages later tomorrow night and early Friday in the Mid-Atlantic/NE US. The cold front and an associated heavy rain band may pass through the DC metro around 1AM on Friday, around 4AM in Philly, and around 7AM in the NYC metro region.

Behind the strong cold front, temperatures are likely to crash on Friday in the I-95 corridor from their early days highs to at or below freezing by late in the day.  This rapid drop in temperatures following the passage of the cold front could result in a quick ice-up of any leftover standing water on untreated surfaces. There is the chance on Friday for a few snow showers in the I-95 corridor as the colder air pours into the region.  Elsewhere, the rain will change to accumulating snow later tomorrow across portions of the Ohio Valley such as in eastern Ohio and also in the western part of the Mid-Atlantic/NE US from West Virginia to western Pennsylvania to western New York State. High pressure takes control on Friday night and the weekend will start off quite cold with temperatures on Saturday struggling to reach the freezing mark in the I-95 corridor region from DC-to-Philly-to-NYC.

Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com

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