1:15 PM | **Cold shot reaches the Mid-Atlantic/Northeast US next Tuesday/Wednesday…lake effect snow showers for the first time this season**
Paul Dorian
Much colder-than-normal air will dominate the eastern half of the nation by the time we get to later Tuesday and Wednesday of next week. Map courtesy NOAA, tropicaltidbits.com
Overview
There have been a few chilly air masses that have reached the Mid-Atlantic/Northeast US in recent weeks, but the one destined to arrive here for next Tuesday and Wednesday will likely be the chilliest so far this season. A deep upper-level trough of low pressure will tend to rotate around and intensify during the next few days over the Great Lakes and southern part of Canada and then this system will spin its way into the eastern US by the middle of next week. With lots of instability in the atmosphere and the cold air mass pushing over the still relatively warm of the Great Lakes, snow showers are likely just downstream for the first time this season.
Snow showers (shown in blue) will develop later next Tuesday and Wednesday in portions of the northeastern states and Great Lakes for the first time this season. Map courtesy NOAA, tropicaltidbits.com
Details
There is a strong cool front working its way into the northeastern states today and it is generating numerous showers at mid-day and embedded thunderstorms will likely form later this afternoon. While it will turn a bit cooler on Friday following the frontal passage, the air mass on the way is rather moderate and the weekend will turn out to be decent for mid-October. In fact, high temperatures on Saturday and Sunday could end up near the 70 degree mark in portions of the I-95 corridor. By the end of the weekend and certainly during the first half of next week, the relatively quiet weather will give way to more activity as a deep upper-level trough slowly spins its way into the eastern states.
Showers will be possible in the Mid-Atlantic/Northeast US on Sunday night and Monday as the first of a series of disturbances slides to the southeast across the Great Lakes. By Tuesday, vigorous upper-level aloft will tend to rotate around and intensify as it moves into the eastern US and the air mass will turn increasingly colder. In fact, temperatures are likely to be confined to the lowest levels so far this season in terms of afternoon highs – well below-normal for the time of year.
Deep upper-level low will spin its way into the eastern US by the middle of next week and with it will come some of the chilliest air so far this season. Map courtesy NOAA, tropicaltidbits.com
In addition to the chill down, there will be much instability in the atmosphere on Tuesday and Wednesday given the intensifying low pressure system in the upper part of the atmosphere and the cold air moving over still relatively warm waters of the Great Lakes. This should result in some snow shower activity in downstream locations of the lakes for the first time this season. Specifically, snow showers could take place by later Tuesday and Wednesday in the eastern Great Lakes, interior Northeast US, and even in some Mid-Atlantic locations such as the Pocono Mountains of northeastern PA. A pretty quick warm up is likely to come to the eastern US later next week.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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