Severe Weather Coordination Message #2 – Wednesday Afternoon and Evening 9/15/21 Severe Weather Potential

Hello to all…

..A Strong cold front will move through Southern New England Wednesday Afternoon through Thursday Morning bringing the potential for severe weather Wednesday Afternoon and Evening..
..Scattered Strong to Severe Thunderstorms are likely Wednesday Afternoon and Evening anytime after 3 PM through midnight particularly over Western and Northern Massachusetts and Northwest Connecticut though areas as far east as the I-95 corridor of Southern New England should monitor. Strong to damaging winds, hail, heavy downpours leading to urban and poor drainage flooding and frequent lightning are the main threats with an isolated tornado as a secondary threat..
..The Storm Prediction Center (SPC) has continued Western and Northern Massachusetts and Northwest Connecticut with a slight expansion into Hartford CT to Worcester Mass. in a slight risk for severe weather and the rest of Southern New England from the I-95 corridor north and west in a marginal risk for severe weather for Wednesday and the Weather Prediction Center (WPC) has placed much of Southern New England along, north and west of the I-95 corridor in a marginal risk for excessive rainfall..
..SKYWARN Self-Activation will monitor any activity overnight Tuesday Night and particularly the severe weather potential for Wednesday Afternoon and Evening..

Another round of potential severe weather is expected for Southern New England this Wednesday Afternoon and Evening. The headlines depict the current thinking. Key factors include:
1.) Timing of the cold front and strong dynamics into the region. This looks most favorable for the locations in a slight risk area for severe weather and particularly western and northern Massachusetts.
2.) How far south and east the severe weather potential extends pending on the timing of the cold front, forcing along the front as it moves southeast and the location of the strongest wind shear levels.
3.) The overall intensity of the strong to severe thunderstorms as if conditions line up and overlap favorably, this could be a fairly widespread severe weather event with fairly numerous pockets of wind damage in particular over the slight risk area of Western and Northern Massachusetts and Northwest Connecticut. There is also a chance the most significant severe weather could stay further north into Northern New England with more isolated severe thunderstorms in Western and Northern Massachusetts and this will be watched through the day though current trends are shifting the potential slightly further south and east hence the expansion of the slight risk for severe weather.

SKYWARN Self-Activation will monitor the severe weather potential for Wednesday 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, WPC Excessive Rainfall Outlook and SPC Day-1 Convective Outlook:

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

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

WPC Excessive Rainfall Outlook:
https://www.wpc.ncep.noaa.gov/qpf/ero.php?opt=curr&day=1

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 (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
http://www.wx1box.org
Like us on Facebook – http://www.facebook.com/wx1box
Follow us on Twitter – http://twitter.com/wx1box