The NWS has issued a Severe Thunderstorm Watch for Litchfield, Hartford, Tolland, and Windham Counties until 7:00 PM.
The Storms Prediction Center (SPC) has placed most of the state into the Slight Risk Category for severe thunderstorms this afternoon. A cool front currently located in eastern New York state is expected to move gradually to the southeast this afternoon. A line of thunderstorms is currently forming just to the northwest of Connecticut in eastern New York State. The HRRR model is forecasting this line of thunderstorms to move gradually across the state from northwest to southeast between 1:00 PM – 10:00 PM. The SPC is forecasting that any thunderstorms that develop will have a 15% chance of containing strong winds and a 2% chance for an isolated tornado.
The most significant impact may come from extremely heavy rainfall. The atmosphere is very moist with dewpoints in the mid 70’s and the HRRR model is forecasting a general 1” – 3” of rain over the next 10 hours (see map to the right). However, the HRRR model is forecasting a few pockets of 4” – 6” rainfall (see blue shading) as these storms move across the state. The current location of these pockets changes from run to run so towns should not focus on the exact locations in the current model. It appears likely that a few towns will experience extremely heavy rainfall and significant urban flooding. The timing of these thunderstorms (rainfall rates up to 3” per hour) may have a direct impact on the afternoon rush hour causing moderate urban flooding with significant ponding on some roads. The NWS has issued flood watches for most of the state except for New London County.
The Department of Emergency Services and Public Protection Division of Emergency Management and Homeland Security will continue to closely monitor conditions this afternoon.