Flash floods in Connecticut kill at least 2, as some towns hit by ‘1,000-year’ rain events

Swaths of western Connecticut and Long Island were hit by heavy rainfall on Sunday into Monday, leading to flash floods and rescue operations – and officials confirmed Monday that at least two people were killed. The extreme weather caused power outages, rail disruptions and the closure of some state parks. Some towns experienced a “1,000-year” rain event, meteorologists said.

A flash flood warning was declared by the National Weather Service for parts of Fairfield, New Haven, Litchfield and Hartford counties in Connecticut, the state’s emergency management services said on X. The towns of Oxford and Southbury in New Haven County were among those affected.

In a briefing on Monday, local officials said two bodies had been recovered from Little River following the deluge. Col. Daniel Loughman, Connecticut State Police commanding officer, noted reports that two women had been swept away by floodwaters, and “it is believed that the recoveries were of the individuals witnessed and reported swept away.”

The two women were Oxford residents, the town’s first selectman, George Temple, said in the briefing.

Data from the NWS late Sunday showed nearly 10 inches of rain lashing the town of Monroe in Fairfield County, with Middlebury in New Haven County recording 9.55 inches of rainfall. Meteorologists said that rainfall in some towns would count as a 1,000-year rain event, or one that has a 0.1% probability of occurring in any given year.

Meteorologist Jacob Feuerstein wrote on X that the 1,000-year rain threshold was narrowly broached in Shelton, Connecticut. Craig Ceecee, another meteorologist, posted that a part of western Connecticut recorded 4 to 6 inches of rain in three hours, making it a once-in-1,000 year event, based on National Oceanic and Atmospheric Administration calculations.

Ryan Hanrahan, chief meteorologist at NBC Connecticut, said that 10 inches of rain over 12 hours, around the towns of Oxford and Southbury, made it close to a 1,000-year event.

As day turned to night, a new area of torrential rainfall inundated west-central Long Island to the east of New York City. A flash flood emergency was hoisted by the Weather Service for northwest Suffolk County during predawn on Monday.

Meteorologist Nick Bassill, director of the New York Mesonet, pointed to one-hour rainfall of 3.5 inches in Stony Brook around 1 a.m. Monday. About 9 inches of rain fell there, qualifying it as a part of another 1,000-year rain event just hours after the one in Connecticut.

Multiple water rescues and road washouts were reported by local officials.

“I don’t think our town is used to flash floods and a lot of people did the absolute wrong thing, which is trying to drive through without knowing what is on the other side,” Temple said in the Monday briefing.

Earlier in the day, the NWS forecast severe thunderstorms and flash flooding for areas in the Mid-Atlantic and Northeast United States through Monday.

NWS issued flash flood and severe thunderstorm warnings for other locations in New Jersey, New York and New England.

Government forecasters are expecting additional heavy rain potential Monday as a cold front begins to clear tropical moisture from the Northeast. A Level 2 of 4 flash flood risk runs from Connecticut through Vermont and New Hampshire, while there is potential for downpours from southeast Virginia to northern Maine.

Connecticut Gov. Ned Lamont described the flooding as “severe” and warned the public that several roads in western Connecticut were closed.

“We are coordinating with municipal officials to respond to today’s severe flooding and ensure public safety in the impacted regions,” he said on X.

Social media visuals showed floodwaters gushing on streets and roads, many of which appeared impassible.

Authorities in the town of Southbury requested civilians stay off roads and not drive through floodwaters. “There are approximately 800 power outages, 15 roadways are completely closed due to flooding conditions and multiple partial roadway closures throughout town,” city officials said in an update late Sunday on Facebook, adding that the Pomperaug River is flowing 3.5 feet above flood level.

The Metropolitan Transportation Authority announced the suspension of Waterbury and Danbury rail services through Monday. At least two state parks were closed due to the floods, Connecticut State Parks said on X.

Extreme precipitation events are increasing in frequency and are expected to continue doing so in most of the country, but particularly in the Northeast, according to NOAA. Although climate change did not cause the individual event, added moisture in the atmosphere made it worse than it would have otherwise been.

“We need to address this issue as a longer-term challenge. Resilience against climate change is not just for the coastline. Flash flood and other disasters affect all of Connecticut,” Sen. Richard Blumenthal, D-Conn., said in the Monday briefing. “We all have a stake, in planning and preparing.”