Remnants of Florence to bring heavy rain

September 17, 2018

The remnants of Tropical Storm Florence that dropped up to 30 inches of rain in the Carolinas, will move into Connecticut early Tuesday.

The heaviest rain is expected to fall in northern Connecticut where more than 2 inches could fall. Litchfield, Hartford, Tolland and Windham counties are under a Flash Flood Watch until 2 a.m. Wednesday.

Areas like New Milford and Torrington are in the 1 to 2-inch range.

The Connecticut shoreline is forecast to receive up to an inch of rain, with locally higher amounts possible.

The remnants of Florence, now a tropical depression, will not bring any strong winds. Wind speed between 7 to 10 mph from the south are expected Tuesday.

“The main concern for Tuesday is the potential heavy rainfall as tropical moisture from the remnants of Florence continue to interact with an approaching frontal zone and upper trough,” the National Weather Service says. “Showers and embedded thunderstorms will be increasing from west to east through the day.”

Estimates of rainfall estimates vary.

The NWS’s Boston office has higher rainfall forecasts for Connecticut including 1 to 3 inches in southern Connecticut and 2 to 3 inches from Waterbury to Windsor Locks. Up to 4 inches is possible in central to northern Massachusetts.

The Albany office forecasts 1.5-2 inches for most of Connecticut. It put the northeast of the state in the 2-3 inch range.

The NWS’s hourly forecast had the best chance of rain between 9 a.m. and 5 p.m. Wednesday.

The rain will further increase this year’s year-to-date totals. As of Monday, with 35.4 inches, Sikorsky Memorial Airport was 5 inches above normal, according to the Northeast Regional Climate Center. White Plains airport, near Greenwich, and Tweed-New Haven are about 2 inches above average; Danbury’s total precipitation for 2019 was average with 34.85 inches.

The system will moves offshore Tuesday evening bringing an end to the precipitation.

High pressure returns for Wednesday. Daytime temperatures will be in the middle and upper 70s and nighttime temperatures will generally be in the 60s and low 70s.

The forecast

Today: Patchy fog before 8am. Otherwise, partly sunny, with a high near 78. Calm wind becoming south around 6 mph in the afternoon.

Tonight: Showers likely, mainly after 3 a.m. Cloudy, with a low around 71. South wind 5 to 7 mph. Chance of precipitation is 60 percent. New precipitation amounts between a tenth and quarter of an inch possible.

Tuesday: Showers likely, then showers and possibly a thunderstorm after 9 a.m. Some of the storms could produce heavy rainfall. High near 78. South wind 7 to 10 mph. Chance of precipitation is 90 percent. New rainfall amounts between three quarters and one inch possible.

Tuesday Night: Showers likely and possibly a thunderstorm before midnight, then a slight chance of showers between midnight and 3 a.m. Some of the storms could produce heavy rainfall. Mostly cloudy, with a low around 64. North wind 5 to 7 mph. Chance of precipitation is 60 percent. New precipitation amounts between a quarter and half of an inch possible.

Wednesday: Mostly sunny, with a high near 74. North wind around 9 mph.

Update hourly