Severe Weather Coordination Message #1 – Monday Afternoon and Evening – 7/20/20 Severe Weather Potential

Hello to all…

..Isolated to Scattered Strong to Severe Thunderstorms are possible Monday Afternoon and Evening in much of Southern New England away from Southeast Coastal New England. Strong to damaging winds, hail, frequent lightning, and heavy downpours with the potential for urban to poor drainage flooding are the main threats. The Storm Prediction Center (SPC) has placed Eastern Connecticut, Rhode Island and Eastern Massachusetts away from the southeast coast in a marginal risk for severe weather..
..SKYWARN Self-Activation will monitor the severe weather potential for Monday Afternoon and Evening..

Another day of intense heat and humidity will affect Southern New England Monday. A cold front will swing through the area Monday Afternoon and evening. The headlines depict the current thinking. Key factors include:

1.) The timing of the cold front with the time of max heating and destabilization
2.) The amount of forcing or triggering in the atmosphere. It could be strongest north of Southern New England but with the atmosphere so unstable, the instability could compensate for less triggering in the atmosphere and it may only take a small trigger in the atmosphere to allow for strong to severe thunderstorm development.
3.) The marginal wind shear and whether this will be sufficient for strong to damaging winds. Its noted that in Michigan, wind gusts over 80 MPH occurred with severe thunderstorms along the cold front. Its possible wind fields could be stronger than modeled and will bear watching.

SKYWARN Self-Activation will monitor the severe weather potential for Monday Afternoon and Evening. Another coordination message will be posted by 10 AM Monday Morning. Below is the NWS Boston/Norton Area Forecast Discussion, Enhanced Hazardous Weather Outlook and SPC Day-2 Convective Outlook:

NWS Boston/Norton Area Forecast Discussion:
https://kamala.cod.edu/ma/latest.fxus61.KBOX.html

NWS Boston/Norton Experimental Enhanced Hazardous Weather Outlook:
https://www.weather.gov/box/ehwo

SPC Day-2 Convective Outlook:
https://www.spc.noaa.gov/products/outlook/archive/2020/day2otlk_20200719_1730.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)
Work Phone #: 508-346-2929 (8 AM-5 PM)
Email Address: rmacedo@rcn.com
http://ares.ema.arrl.org
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