Posts

John Homenuk

Isolated severe thunderstorms likely today

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A deep southwesterly flow has developed this morning, allowing for increasingly warm mid level temperatures to advect into the area. Surface temperatures, as a result, are expected to rise much higher today than they did on Wednesday. Temperatures in the low 90’s are anticipated by early afternoon throughout much of New Jersey and New York City. Humidity will be on the rise as well. An Air Quality Alert is in effect for parts of NJ and NYC today, which means you should avoid prolonged exposure to the heat and humidity as air quality will be subpar. 

A wind shift boundary, sitting just to our north over the Lower Hudson Valley, will serve to enhance the development of instability to its south. Models are in good agreement that upward of 2500 joules of Surface Based CAPE will develop from Eastern PA into New Jersey and New York City during this afternoon. These numbers are quite high for our area — especially during this time of year.

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John Homenuk

Heat, severe weather threat will build this week

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Yesterday we wrote that “summer weather was finally here”. Well, if you’ve been here long enough you know that “summer weather” refers to sunshine and warmth, but also brings the potential for thunderstorms, heavy rain, and strong winds. We were able to luck out on Monday, as strong and severe thunderstorms (which produced widespread reports of damaging winds) stayed off to our west. Tuesday will be first day which storms will move through our area.

While the storms on Tuesday aren’t expected to be quite as severe as the ones which brought wind damage to the interior Northeast on Monday, they will still have the potential to produce gusty winds, small hail, and heavy rain. Lightning will, of course, also be a threat in any storms that develop. Instability will be a bit less than ideal for widespread storms, but wind shear may help them organize. The Storm Prediction Center has issued a Slight Risk for severe thunderstorms, mainly to the north of NYC into New England. 

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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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