Severe Weather Coordination Message #1 – 8/20/19 Severe Weather Potential

Hello to all…

..Isolated to Scattered Strong to Severe Thunderstorms are likely Wednesday Afternoon and Evening, 8/21/19, across much of Southern New England particularly along and north of the Boston to Providence line. Strong to damaging winds, hail, frequent lightning and heavy rainfall leading to urban and poor drainage flooding to flash flooding are the main threats with the main timeframe between 2-9 PM EDT Wednesday..
..The Storm Prediction Center (SPC) has placed much of Southern New England in a slight risk for severe weather except for South Coastal Massachusetts, Southeast Coastal Rhode Island and Cape Cod and the Islands which is in a marginal risk for severe weather..
..SKYWARN Activation with Ops at NWS Boston/Norton will commence by 2 PM EDT Wednesday to monitor severe weather potential..

A warm front will push its way through Southern New England on Wednesday. Most models take this warm front through the area with little to no cloud cover and precipitation setting the stage for a favorable environment for severe weather potential across the region with sufficient wind shear profiles and significant heating for destabilization and high instability with a trigger in an approaching cold front. There are a few models, however, that bring the warm front in with shower and thunderstorm activity, cloud cover, and perhaps slow the progress of the warm front which could mitigate the severe weather potential more if that were to transpire. At this time, the potential for a reasonable amount of strong to severe thunderstorms is likely but the position of the warm front, how active it is and any cloud cover will need to be monitored to determine the extent of the severe weather potential more clearly. A slower and more active passage may limit the severe weather potential while a more rapid and less active passage of the warm front could increase the severe weather potential. This will be monitored and updated Wednesday Morning. The headlines of the message depict the current thinking.

SKYWARN Activation with Ops at NWS Boston/Norton will commence by 2 PM EDT Wednesday to monitor severe weather potential. Another coordination message will be posted by 1000 AM Wednesday Morning. Below is the NWS Boston/Norton Hazardous Weather Outlook, Enhanced Hazardous Weather Outlook and SPC Day-2 Convective Outlook:

NWS Boston/Norton Hazardous Weather Outlook:
https://kamala.cod.edu/ma/latest.flus41.KBOX.html

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

SPC Day-2 Convective Outlook:
https://www.spc.noaa.gov/products/outlook/archive/2019/day2otlk_20190820_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
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