Severe Weather Coordination Message #1 – Tuesday Night 9/14/21 & Wednesday Afternoon-Wednesday Night 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 conditionally Tuesday Night with the focus and more potent severe weather potential 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..
..A conditional threat for Isolated strong to severe thunderstorms is possible overnight Tuesday after midnight through 6 AM across Western and Northern Massachusetts..
..The Storm Prediction Center (SPC) has placed Western and Northern Massachusetts and Northwest Connecticut 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 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. The severe weather potential overnight Tuesday Evening is very conditional and low risk but will need monitoring and will hinge on favorable instability and wind shear parameters and whether there is enough moisture or a trigger for any strong to severe thunderstorms to develop.
A more significant and potent severe weather event is likely for Wednesday Afternoon and Evening and 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 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.
SKYWARN Self-Activation will monitor any activity overnight Tuesday Night and particularly the severe weather potential for Wednesday Afternoon and Evening. Another coordination message will be posted by 11 AM Wednesday Morning. Below is the NWS Boston/Norton Area Forecast Discussion, Enhanced Hazardous Weather Outlook, WPC Excessive Rainfall 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 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=2
SPC Day-2 Convective Outlook:
https://www.spc.noaa.gov/products/outlook/archive/2021/day2otlk_20210914_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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