Severe Weather Coordination Message #2 – Sunday 7/20/25 Severe Weather Potential
Hello to all…
..The morning round of potential thunderstorms for Southeast New England has tracked further south with only showers and an isolated thunderstorm expected over Cape Cod and the Islands this morning. There will then be a period of dry weather followed by the potential for isolated to scattered strong to severe thunderstorms Sunday Afternoon and Evening between 2-10 PM with strong to damaging winds, hail, frequent lightning and heavy downpours leading to urban and poor drainage flooding as the main threats..
..The Storm Prediction Center has maintained Southern New England in a Slight Risk for Severe Weather except for Cape Cod and the Islands which is in a marginal risk for severe weather for Sunday Afternoon and Evening..
..SKYWARN Self-Activation with Amateur Radio Call-Up Nets are likely Sunday Afternoon and Evening for much of the area where isolated to scattered strong to severe thunderstorms occur. Pictures and videos of storm damage, hail, and flooding can be sent as a reply to this email, via our WX1BOX Facebook, X and Bluesky feeds or to the email address pics@nsradio.org with credit given to the spotter unless otherwise indicated..
Sunday has potential to be a fairly active day in Southern New England with a brief period of heat and humidity. Morning thunderstorm activity with localized flood potential is tracking south and east of Southeast New England though showers and an isolated thunderstorm could occur through midday today particularly over the islands and possibly Cape Cod. As this area departs, there will be a period of dry weather with heating and destabilization that sets the stage for isolated to scattered severe thunderstorm development. The headlines depict the current thinking. Key factors include:
1.) The track of morning thunderstorms Sunday Morning with flood potential for Southeast New England is further south than modeled yesterday morning so while there will be some showers and an isolated thunderstorm, this should move out by midday. Satellite pictures show breaks in cloud cover especially across Northern Massachusetts and further breaks back into New York State that should allow for heating and destabilization for much of the region which will be monitored closely.
2.) Timing of the cold front to take advantage of favorable instability and shear profiles to offset a few negative parameters on severe weather potential. Current timing would be prime for development of strong to severe thunderstorms Sunday Afternoon and Evening if expected heating and destabilization occurs.
3.) As always with severe/non-severe thunderstorm events, not all locations will receive a severe/non-severe thunderstorm. They will be isolated to scattered with pockets of wind damage, hail and urban/poor drainage flooding in those isolated to scattered locations.
SKYWARN Self-Activation with Amateur Radio Call-Up Nets are likely Sunday Afternoon and Evening for much of the area where isolated to scattered strong to severe thunderstorms occur. Pictures and videos of storm damage, hail, and flooding can be sent as a reply to this email, via our WX1BOX Facebook, X and Bluesky feeds or to the email address pics@nsradio.org with credit given to the spotter unless otherwise indicated. This will be the last coordination message as we shift into operations mode. Below is the NWS Boston/Norton Area Forecast Discussion, Enhanced Hazardous Weather Outlook and SPC Day-1 Convective Outlook:
NWS Boston/Norton Area Forecast Discussion:
https://forecast.weather.gov/product.php?site=NWS&issuedby=BOX&product=AFD&format=CI&version=1&glossary=1&highlight=off
NWS Boston/Norton Enhanced Hazardous Weather Outlook:
https://www.weather.gov/erh/ghwo?wfo=box
SPC Day-1 Convective Outlook:
https://www.spc.noaa.gov/products/outlook/day1otlk.html
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)
Email Address: rmacedo@rcn.com
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