Severe Weather Coordination Message #1 – Friday 8/18/23 Severe Weather Potential

Hello to all…

..Isolated to Scattered Strong to Severe Thunderstorms are possible in two rounds Friday Morning through late Afternoon Friday with strong to damaging winds, hail, frequent lightning and heavy rainfall leading to urban and poor drainage flooding as the primary threats with an isolated tornado as a secondary threat. The Storm Prediction Center (SPC) has placed all of Southern New England in a marginal risk for severe weather for Friday..
..SKYWARN Self-Activation will monitor the severe weather potential for Friday..

A dynamic warm front followed by cold frontal system will impact Southern New England. Despite this system moving in earlier in the day than peak heating, jet dynamics will likely allow for at least isolated to scattered strong to severe thunderstorms in Southern New England. The headlines depict the current thinking. Key factors include:

1.) The level of instability that can be generated despite timing of the system prior to peak heating.

2.) Wind shear and jet dynamics with this system are more typical of fall frontal passage than summer time and these parameters may offset other unfavorable instability parameters.

3.) Whether there will be two rounds of strong to severe thunderstorms, one in the morning through early afternoon and a second round in the mid to late afternoon. This will depend on the timing of the frontal system through the region and whether conditions dry out so much ahead of the cold front that a second round of strong to severe thunderstorms are unable to develop.

SKYWARN Self-Activation will monitor the severe weather potential for Friday. Another coordination message could be issued by 9 AM Friday Morning if time allows and we are not already in operations mode. 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://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-2 Convective Outlook:
https://www.spc.noaa.gov/products/outlook/archive/2023/day2otlk_20230817_1730.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
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