Severe Weather Coordination Message #1 – Thursday Afternoon & Evening 7/20/22 – Heat & Severe Weather Potential

Hello to all…

..Intense heat and humidity expected through Thursday with a cold front which will bring less humid air that will be a trigger for isolated to scattered strong to severe thunderstorms with damaging winds, hail, frequent lightning and heavy rainfall with urban and poor drainage flooding as the main threats. The Storm Prediction Center has placed much of Southern New England in a slight risk for severe weather north of South Coastal Rhode Island and Massachusetts with south coastal areas in a marginal risk for severe weather. The threat timeframe is between 12-8 PM Thursday Afternoon and Evening..
..A Heat Advisory is in effect through 800 PM Thursday Evening for much of Southern New England including Northern Connecticut, Rhode Island except for extreme south coastal areas and much of Western, Central and Eastern Massachusetts for heat indices up to 100-102 degrees expected. Use caution if outdoors doing strenuous activities and drink plenty of non-alcoholic and non-caffeinated drinks during this period..
..SKYWARN Self-Activation will monitor the severe weather potential for Thursday Afternoon and Evening..

We continue to be in a stretch of oppressive heat and humidity over the region that will last through Thursday. During Thursday Afternoon and evening, a cold front or more like a dewpoint front separating higher dewpoint air from lower dewpoint air will move across the region and set the stage for isolated to scattered strong to severe thunderstorm development across much of interior Southern New England with Northern Connecticut, Western, Central and Northeast Massachusetts the favored areas in Southern New England. The headlines depict the current thinking. Key factors include:

1.) The amount of forcing and the location of the cold front as it moves through the area at time of peak heating. This will determine the coverage and areal extent of severe thunderstorms in Southern New England. Some models favor just Northern New England with the most widespread activity with less activity in Southern New England while other models keep the coverage more widespread across both Northern and Southern New England away from south coastal areas. This should become better defined as we go into tomorrow morning.
2.) Instability, wind shear profiles and other factors are all quite favorable for severe thunderstorm development so if the forcing arrives at the time of peak heating, that will make severe thunderstorms more widespread but if it remains over Northern New England then activity will be isolated or scattered. In either case, not every city or town will receive a strong or severe thunderstorm but the amount of forcing and how quickly it shifts east will determine the coverage over the region.

SKYWARN Self-Activation will monitor the severe weather potential for Thursday Afternoon and Evening. Below is the NWS Boston/Norton Heat Advisory Statement, Area Forecast Discussion, Hazardous Weather Outlook and SPC Day-2 Convective Outlook…

NWS Boston/Norton Heat Advisory Statement:

NWS Boston/Norton Area Forecast Discussion:

NWS Boston/Norton Enhanced Hazardous Weather Outlook:

SPC Day-2 Convective Outlook:

Respectfully Submitted,

Robert Macedo (KD1CY)
ARES SKYWARN Coordinator
Eastern Massachusetts ARES Section Emergency Coordinator
Home Phone #: (508) 994-1875 (After 6 PM)
Home/Data #: (508) 997-4503 (After 6 PM)
Work Phone #: 508-346-2929 (8 AM-5 PM)
Email Address: