11:45 AM (Tuesday) | **An energetic cold frontal passage on Wednesday night in the Mid-Atlantic region...50 mph wind gusts possible on Thursday**
Paul Dorian
An energetic frontal passage will take place tomorrow night in the Mid-Atlantic region and it’ll be supported by a “negatively-tilted” upper-level trough; map courtesy NOAA, tropicaltidbits.com
Overview
There will be mild conditions and occasional rain or drizzle in the Mid-Atlantic region this afternoon, tonight and on Wednesday along with patchy, dense fog at times; especially, in the overnight hours. A much more energetic weather situation is evolving for tomorrow night as a strong cold front will come barreling through the Mid-Atlantic with possible downpours and perhaps even some strong-to-severe thunderstorm activity. It’ll turn very windy and much colder following the frontal passage late Wednesday night and Thursday with NW wind gusts possible to 50 mph. The colder-than-normal air conditions that develop on Thursday will stick around right through Sunday as a reinforcing shot of cold air will arrive by the early part of the weekend.
Intensifying low pressure will be situated right over southeastern Pennsylvania by later tomorrow night and there can be some locally heavy rainfall along with possible strong thunderstorm activity; map courtesy NOAA, tropicaltidbits.com
Details
Several waves of low pressure will push along a frontal boundary zone over the next 24 hours or so producing occasional rain or drizzle and there is likely to be some patchy, dense fog at times; especially, in the overnight hours. It’ll stay relatively mild through the period with highs of 50+ degrees both this afternoon and tomorrow afternoon in the DC-to-Philly-to-NYC corridor. By later tomorrow, surface low pressure will form along the Blue Ridge Mountains and intensify on its way to the northeast as it’ll have plenty of support in the upper atmosphere. Specifically, a long-wave trough of low pressure will push eastward later tomorrow from the central US into the Great Lakes/Ohio Valley region and it’ll take on a “negatively-tilted” trough axis (i.e., oriented northwest-to-southeast) which will enhance upward motion in the I-95 corridor. This system will feature a powerful jet streak in the upper part of the atmosphere as well and given the strengthening wind fields and increasing wind shear values, isolated severe thunderstorms may develop late tomorrow into tomorrow night as a strong cold front pushes from west-to-east across the Mid-Atlantic. Showers will accompany the frontal passage late tomorrow and tomorrow night and there can be brief downpours to go along with gusty winds and perhaps damaging wind gusts in strong-to-severe thunderstorms.
A strong cold front will barrel through the Mid-Atlantic region tomorrow night and “frontogenesis” (shown in purple) will be quite high adding to the instability in the atmosphere; map courtesy NOAA, tropicaltidbits.com
Following the front, winds will increase in intensity from a northwesterly direction and temperatures will drop sharply in the overnight hours. Rain is likely to change to snow across higher elevation interior sections of the Mid-Atlantic including in, for example, the Poconos Mountains of northeastern Pennsylvania where a quick couple of inches could fall. There is even a chance that a few snow showers work their way into the northern and western suburbs along the I-95 corridor late tomorrow night as the colder air arrives.
On Thursday, stiff NW winds could gust to 50 mph and it’ll feel much colder in the Mid-Atlantic compared to what we’ve experienced during the past couple of days with temperatures struggling to climb from early day highs in the low-to-mid 40’s. Snow showers and snow squalls are likely on Thursday afternoon in central and northeastern Pennsylvania as the atmosphere will remain quite unstable. Unlike most of our recent (brief) cold snaps, this one is likely to persist for a few days as a reinforcing shot of cold air will push in by the early part of the weekend and it could be associated with some snow shower activity for parts of the Mid-Atlantic region. It looks likely, however, that a warm-up will take place by the middle part of next week.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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