Severe Weather Coordination Message #2 – Saturday PM & Evening 7/18/26 Severe Weather & Flash Flood Potential
Hello to all…
..A strong cold front will approach Southern New England Saturday Afternoon and evening setting the stage for potentially two rounds of isolated to scattered strong to severe thunderstorms one Saturday Early to Mid-Afternoon and the other Saturday late Afternoon & Evening with the more dominant severe weather potential late this afternoon and evening. Much of Southern New England has severe weather potential but the greatest risk is over Western and Central Massachusetts, Connecticut, Rhode Island and into South Coastal Massachusetts..
..The Storm Prediction Center (SPC) has Western and Central Massachusetts and all of Connecticut and Rhode Island in a slight risk for severe weather Saturday Afternoon and Evening and the rest of Southern New England along and north and west of the Cape Cod Canal in a marginal risk for severe weather. Threat potential timeframe is between 12 PM-12 AM Saturday though the highest risk in this timeframe maybe from around 3 PM-12 AM. Strong to damaging winds, hail, frequent lightning and heavy downpours leading to urban and poor drainage flooding are the primary risks but even an isolated tornado cannot be ruled out particularly in the slight risk for severe weather area..
..SKYWARN Self-Activation with Amateur Radio Call-Up Nets are possible Saturday Afternoon and Evening based on the severe weather and flash potential. Pictures and videos of wind damage, hail, flooding etc. can be sent as a reply to this email, via our Facebook/X/Bluesky feeds or the email address pics@nsradio.org with credit given to the spotter unless otherwise indicated..
The headlines depict the current thinking on severe weather potential for this Saturday Afternoon and Evening. Key factors include:
1.) Strong wind shear profiles are present but the degree of instability is in question between cloud cover and smoke. The level of instability or to the degree that strong wind shear can compensate limited instability will determine how significant and widespread severe weather can be in the area.
2.) Timing of the cold front to maximize instability that is present. The timing on some models has sped up a bit which is why the Slight risk has expanded eastward into more areas of Southern New England.
3.) A smoke plume may move through Southern New England which could limit instability. If its very thick like it was on Wednesday across all of Southern New England or like it was Thursday in Connecticut, it could limit severe weather potential but if its thin or moves through quickly like other parts of Southern New England on Thursday, it will be a non-factor.
SKYWARN Self-Activation with Amateur Radio Call-Up Nets are possible Saturday Afternoon and Evening based on the severe weather and flash potential. Pictures and videos of wind damage, hail, flooding etc. can be sent as a reply to this email, via our Facebook/X/Bluesky feeds or the email address pics@nsradio.org with credit given to the spotter unless otherwise indicated. This will be the last coordination message as we move to monitoring and 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
Home/Data #: (508) 997-4503
Email Address: rmacedo@rcn.com
https://ares.ema.arrl.org
https://www.wx1box.org
Like us on Facebook – https://www.facebook.com/wx1box
Follow us on Twitter – https://twitter.com/wx1box
Subscribe on YouTube – https://www.youtube.com/@wx1box-nwsboston-amateur-radio