2:20 PM | ***Strong-to-severe thunderstorm threat later today/early tonight with arrival of cool front…noticeably less humid tomorrow and nice weather continues Thursday and Friday***
Paul Dorian
Numerous showers and thunderstorms will arrive in the I-95 corridor region late today/early tonight associated with a strong cool front and some of the storms can be on the strong-to-severe side with downpours and very gusty winds. Map courtesy NOAA, tropicaltidbits.com
Overview
It has been quite dry in recent weeks across the Mid-Atlantic/Northeast US and some rain would be a welcome break in this pattern. A strong cool front will indeed bring some rain to the area later today and tonight and some of the thunderstorms that develop can be on the strong-to-severe side with brief downpours and gusty winds. The cool front clears the coast by morning and tomorrow will become quite breezy and noticeably less humid than the steamy conditions of both today and yesterday. The nice weather will continue on Thursday and Friday as strong high pressure builds into the northeastern states during the latter part of the week.
Showers and thunderstorms have increased in coverage across western portions of the Mid-Atlantic region at mid-day and will push to the east and reach the I-95 corridor late today/early tonight. Radar images courtesy NOAA, College of DuPage
Discussion
The combination of a strong surface cool front, vigorous support in the upper atmosphere, and an entrenched very warm and humid air mass will result in numerous showers and thunderstorms later today and tonight in the Mid-Atlantic/Northeast US. The most likely timetable for the storm threat along the I-95 corridor is as follows: 3-6 PM in DC metro, 4-8 PM in Philly metro, and 5-9 PM in NYC metro. Morning clouds have given way to increasing amounts of sunshine and daytime heating will help to destabilize the atmosphere over the next few hours. As a result, thunderstorms will become more widespread and tend to strengthen as they approach the I-95 corridor later in the day and some can reach strong-to-severe levels containing brief heavy rainfall and gusty winds. Upper-level support in the form of a vorticity maximum over the Great Lakes will help to promote upward motion later today contributing to the overall instability in the atmosphere and the potential of those strong-to-severe storms.
In addition to a strong surface cool front, a contributing factor to today’s unstable atmosphere is a strong short-wave aloft that will increase upward motion in the Mid-Atlantic region. Map courtesy NOAA, tropicaltidbits.com
The showers and thunderstorms will tend to weaken later tonight as they approach the coastline and drier air will begin to push in from the west in the wee hours of the morning. The day on Wednesday will feature comfortably warm conditions and a noticeable drop in humidity compared to the sultry air mass of the past couple of days. The breeze will also become noticeable tomorrow with gusts later in the day of up to 25 or 30 mph or so. Nice weather will continue on Thursday and Friday throughout the northeastern part of the country as strong high pressure that had its origins in Canada will build into New England by week’s end. The weather this weekend is likely to turn warmer and more humid as the same high pressure systems shifts to a position off the eastern seaboard and a southwesterly flow of air develops on its backside.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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