Severe Weather Coordination Message #2 – Late Monday Night 8/7/23-Tuesday 8/8/23 – Severe Weather & Flood Potential

Hello to all…

..A risk for isolated to scattered strong to severe thunderstorms continues for the overnight hours Monday Night through Tuesday Morning with a second timeframe Tuesday mid-afternoon through early evening. Strong to damaging winds, frequent lightning and heavy rainfall leading to urban and poor drainage flooding to flash flooding are the primary threats with an isolated tornado or waterspout as the secondary threat. The Storm Prediction Center (SPC) has placed continued much of Southern New England in a Marginal risk for severe weather overnight Monday into Tuesday..
..SKYWARN Self-Activation will monitor the severe weather and flood potential overnight Monday through Tuesday. Amateur Radio and non-Amateur Radio SKYWARN Spotters should have multiple ways to receive weather alerts given that some of this severe weather and flood potential will be possible during the overnight/nocturnal period where most people are sleeping..

There is a risk for isolated to scattered strong to severe thunderstorms during the overnight Monday Night to Tuesday Morning timeframe with a second more limited round of isolated to scattered strong to severe thunderstorms Tuesday Afternoon into Tuesday Evening. The headlines depict the current thinking. Key factors include:
1.) Ability of jet dynamics, turning in the atmosphere and instability from very high dewpoints to compensate for other more limited instability parameters to allow for strong to severe thunderstorm development.
2.) The ability for the mesoscale factors of jet dynamics, turning in the atmosphere and high instability to overlap and maximize along with the formation of a triple point low which would increase the severe weather potential.
3.) Flooding from heavy downpours in thunderstorms depending on the intensity of the thunderstorms as they move through the area given still relatively wet conditions particularly in interior Southern New England.
4.) The morning convective potential will determine what occurs later Tuesday Afternoon into early evening. If the morning convection is significant, it will likely produce cloud debris and reduce the convective potential for later in the day Tuesday. if the morning convection is weaker or produces less cloud debris, the convective potential for later in the day would be present and would bear watching. At this time, the greater threat for severe weather appears to be the overnight to morning hours of Tuesday.

SKYWARN Self-Activation will monitor the severe weather and flood potential overnight Monday through Tuesday. Amateur Radio and non-Amateur Radio SKYWARN Spotters should have multiple ways to receive weather alerts given that some of this severe weather and flood potential will be possible during the overnight/nocturnal period where most people are sleeping. This will be the last coordination message unless a significant update to the situation occurs and time allows for an update. 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_20230807_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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