Severe Weather Coordination Message #2 – Monday 7/18/22 Severe Weather Potential

Hello to all…

..Isolated to Scattered Strong to Severe Thunderstorms are likely across Western Massachusetts and Northwest Connecticut and possible through Northeast Connecticut, Northwest Rhode Island and Central and interior Northeast Massachusetts along and northwest of the I-95 corridor Monday Afternoon and Evening with strong to damaging winds, hail, frequent lightning and heavy rainfall with urban and poor drainage flooding as the main threats and an isolated tornado as a secondary threat.
..The Storm Prediction Center (SPC) has placed portions of Western Massachusetts and Northwest Connecticut in a slight risk of severe weather with a marginal risk for severe weather from the I-95 corridor of Boston to Providence north and west through Central and Northeast Massachusetts and Northeast Connecticut..
..SKYWARN Self-Activation will monitor the severe weather potential for Monday Afternoon and Evening..

An area of showers and thunderstorms is moving through the region Monday Morning. The area is mostly showers across interior Southern New England with some strong thunderstorms across South Coasal Connecticut and over Long Island Sound. The activity over Long Island sound will be monitored for an isolated strong to severe thunderstorm over Southeast New England but this area should largely be non-severe and should clear Western and Central Massachusetts and Western and Central Connecticut between 12-2 PM and areas further east around or after 2 PM. After that area moves through, the potential for isolated to scattered strong to severe thunderstorms will be likely in the Slight Risk for severe weather area and possible in the marginal risk for severe weather area for Monday Afternoon and evening. The headlines depict the current thinking. Key factors include:

1.) Amount of heating and destabilization that can occur after the initial showers and thunderstorms move through the area. As of 1030 AM Monday Morning, satellite imagery is showing a lot of clouds but some thinning occurring in Central Pennsylvania and Central New York. This clearing if it becomes more widespread coupled with the very strong shear profiles would set the stage for strong to severe thunderstorm development later this afternoon into early evening. Also, given the strong wind shear, it will not take much heating given the high dewpoint air in the region to allow for isolated to scattered strong to severe thunderstorm development particularly in the slight risk area. The key will be having at least some cloud breaks and the movement of the current rain area east of the slight and marginal risk areas by roughly the 12-2 PM time window and that the warm front gets far enough to the north to allow a good portion of the risk areas to be in the warm sector.
2.) The timing of the cold front and how far east the forcing gets to allow for thunderstorm and severe weather development.
3.) Heavy rainfall is expected. The rain will be beneficial but if its heavy enough and falls in a short enough period of time, it can result in urban and poor drainage flooding in susceptible areas.

SKYWARN Self-Activation will monitor the severe weather potential for Monday 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, SPC Day-1 Convective Outlook and WPC Day-1 Excessive Rainfall 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-1 Convective Outlook:
https://www.spc.noaa.gov/products/outlook/day1otlk.html

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

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
https://ares.ema.arrl.org
https://www.wx1box.org
Like us on Facebook – https://www.facebook.com/wx1box
Follow us on Twitter – https://twitter.com/wx1box