Storm Coordination Message #2 – Thursday 8/4/21 – Heavy Rainfall Flash Flood & Severe Weather Potential

Hello to all…

..Storm system will move through the region Wednesday Night into Thursday Morning bringing heavy rainfall and a few thunderstorms with the low risk of isolated strong to severe thunderstorms in Eastern New England..
..A Flash Flood Watch is now in effect for Wednesday Night through Thursday Morning for all of Rhode Island, Windham County Connecticut, Southern Worcester County and Eastern Massachusetts except for Cape Cod and the Islands for 1-3″ of rainfall with isolated amounts up to 4″ possible. This rainfall combined with a wet month of July will result in a renewed risk for flooding of urban, poor drainage areas, small rivers and streams. The Flash Flood Watch was expanded northwest into Northeast Connecticut and South-Central Massachusetts for this update..
..SKYWARN Self-Activation will monitor for rainfall, flooding and any strong to damaging wind and wind damage reports across Eastern New England Tonight into Thursday Morning..

Another round of heavy rainfall is expected across portions of Eastern New England tonight into Thursday Morning. The headlines depict the current thinking. Key factors include:

1.) High resolution models are in different locations with the heaviest rainfall ranging as far west as Eastern Connecticut, Rhode Island and Central and Northeast Massachusetts to areas further southeast even including Cape Cod and the Islands. The current Flash Flood Watch area represents the highest confidence area for potential flooding concerns. In this update, Windham County Connecticut and Southern Worcester County Massachusetts were included in the Flash Flood Watch as the consensus of models brings the heavy rainfall into these areas with a sharp northwest cutoff on heavy rainfall to the northwest of this area.
2.) With the heaviest rainfall occurring in the Flash Flood Watch and shifting a bit further north and west, areas of Southeast Massachusetts and Rhode Island could see an isolated severe thunderstorm threat develop with strong to damaging winds and the possibility of a couple rotating thunderstorms. This will be monitored closely.
3.) With the wet month of July, if this heavy rainfall falls in the current Flash Flood Watch area or areas further west, the flood potential for urban and poor drainage areas and small rivers and streams will be fairly high. At this time this is looking like the most likely scenario though if it shifts further east into the Cape and Islands, the rain would be beneficial as its been much drier in this area versus the rest of the region.

SKYWARN Self-Activation will monitor for rainfall and flooding reports across Eastern New England tonight into Thursday Morning. This will be the last coordination message as we shift into operations mode. Below is the NWS Boston/Norton Flash Flood Watch Statement, Area Forecast Discussion, Enhanced Hazardous Weather Outlook, SPC Day-1 Convective Outlook and NWS Boston/Norton Rainfall Map:

NWS Boston/Norton Flash Flood Watch Statement:

NWS Boston/Norton Area Forecast Discussion:

NWS Boston/Norton Enhanced Hazardous Weather Outlook:

SPC Day-1 Convective Outlook:

NWS Boston/Norton Rainfall Map:

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:
Like us on Facebook –
Follow us on Twitter –