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John Homenuk

Severe weather outbreak possible in the Midwest today

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Severe weather season is kicking up, and today could feature a dangerous outbreak of storms over the Midwest and North/Eastern Plains states toward parts of the Mississippi River Valley. The Storm Prediction Center has issued a large “Moderate Risk” for severe thunderstorms in those areas, the second highest risk category they use (only High Risk denotes a greater potential), with the potential for widespread damaging wind gusts and strong tornadoes.

A large high pressure ridge, currently situated over the Central United States, is slowly shifting eastward. But, more notably, the high pressure dome is serving as a highway for severe thunderstorm formation on its northern edge. Along the periphery of the ridge, atmospheric disturbances have been sliding east and then southeast from the Northern Plains into the Mississippi Valley. These disturbances are acting to force thunderstorm development within an incredibly unstable and supportive environment for severe thunderstorms.

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John Homenuk

Slight risk for strong storms this evening

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The Storm Prediction Center has placed much of the area from New York City westward in a Slight Risk for severe thunderstorms this afternoon and evening. Ahead of an approaching frontal boundary, warm and humid air is advecting northward into the region. Increasing dew points and surface heating will lead to the development of moderate instability throughout the area by the afternoon hours. Accordingly, the approaching front will aid in the development of storms from Eastern Pennsylvania into Western New Jersey.

These storms will move toward a narrow axis of instability over New Jersey reaching toward New York City this afternoon. Narrow, only because east of New York City a stout marine layer will remain in place. This will keep storms elevated and weaker — temperatures there will be cooler as well with less instability. Nevertheless, the storms will march eastward through New Jersey toward NYC right around the PM Commute. The main threats with any storms will be gusty winds, lightning, and heavy rain.

This post will be updated throughout the day with the latest information including watches and warnings.

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John Homenuk

Showers and storms with gusty winds, small hail today

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3:00pm Update: Showers and embedded thunderstorms continue to approach the area, now in Western New Jersey and shifting eastward. While radar presentation isn’t necessarily eye-grabbing, the winds just above the surface that are mixing down to the surface are impressive.

Philadelphia International Airport recently gusted to 71 miles per hour as thunderstorms passed through. Multiple gusts over 45 miles per hour have been reported in Eastern Pennsylvania. As storms continue to shift eastward toward the axis of more favorable instability and lapse rates, expect these gusts to continue.

None of these storms are currently producing sustained severe-level winds, but we are continuing to monitor the situation. Stay tuned for future updates over the next few hours.

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John Homenuk

Spring Weather: Severe thunderstorms, and the SPC

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Each year, as the atmospheric pattern begins to undergo a transition and wavelengths begin to change, the threat for strong to severe thunderstorms becomes a focus of the meteorological community in New Jersey, New York and Connecticut. Spring, in fact, marks the beginning of “Severe Weather” season in our area — which generally has been known to begin on May 1st. There have obviously been severe thunderstorms before May 1st, but in general the most consistent potential for organized severe storms begins in May and ends in August or September.

Interestingly enough, severe thunderstorms feature some terminology and atmospheric interactions which can be very confusing not only to interpret as meteorologists, but to understand on the public level. Knowing the basics of how organized thunderstorm events develop, and how forecasters attempt to predict and quantify their potential, will help to make things a little less confusing when severe weather season comes around this year.

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