Severe Weather Coordination Message #2 – Monday Late Afternoon and Evening 6/21/21 Severe Weather Potential

Hello to all…

..Isolated to Scattered Strong to Severe Thunderstorms are possible late Monday Afternoon and Evening across Western Massachusetts along and west of the CT River Valley and Northwest Connecticut. Timeframe is between 5-10 PM Monday with strong to damaging winds, hail, frequent lightning and heavy rainfall with urban and poor drainage flooding as the main threats. There have been no changes to the outlook since yesterday..
..The Storm Prediction Center (SPC) has placed Western Massachusetts and Northwest Connecticut along and west of the Connecticut River Valley in a marginal risk for severe weather for late Monday Afternoon and Evening..
..SKYWARN Self-Activation will monitor the severe weather potential for Monday late Afternoon and Evening..

A pre-frontal trough will move through New York and Northern New England and then spread into Southern New England during Monday in the late afternoon and evening and bring the potential for isolated to scattered strong to severe thunderstorms over portions of Western New England. The headlines depict the current thinking and are unchanged from yesterday. Key factors include:

1.) Timing of the pre-frontal trough as earlier timing into Western New England would increase the severe weather potential there but later timing would reduce the potential.
2.) Wind shear profiles are favorable which may compensate for lower instability if current timing in the late afternoon/early evening holds.

SKYWARN Self-Activation will monitor the severe weather potential for Monday late afternoon and evening. 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:

NWS Boston/Norton Enhanced Hazardous Weather Outlook:

SPC Day-1 Convective Outlook:

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:
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