Long Island weather forecast: Possible heavy rains, flooding

A flood watch is in effect across Long Island through Sunday evening as a storm that could produce torrential downpours with 3 to 5 inches of rain moves into the area.

A frontal system bringing showers and thunderstorms will move into the region late Saturday into Sunday, the National Weather Service said Saturday. “Multiple rounds” are expected throughout Sunday with rainfall amounts between 1 and 3 inches. Heavier rainfall could dump 3 to 5 inches in some areas, which could lead to flash flooding in urban and low-lying, flood-prone areas.

Most of Long Island is at a “slight risk” for flooding while areas of northern Nassau, the New York City metro area, northeast New Jersey and the Hudson Valley are at a moderate risk, according to the Weather Prediction Center.

“Long Island has been a little drier, so it’s a little more resilient to the heavier, torrential rainfall,” said Matthew Wunsch, a meteorologist with the weather service.

He said the storm also carries a “marginal risk” for severe thunderstorms, with isolated wind gusts of up to 60 mph possible. Wunsch said the primary risk for Long Island remains flash flooding.

A “high” rip current risk was also issued for ocean beaches along the South Shore. The weather service said the advisory means life-threatening rip currents are likely for people entering the surf zone.

Parts of the Hudson Valley are bracing for additional flash flooding as up to 5 inches of rain could fall in the wake of last week’s devastating, historic storm. The ground remains saturated and river and stream levels are still running high after nearly 9 inches of rain fell in a 24-hour period, leading to a public transit standstill, forced evacuations, collapsed roads and at least one death, according to state officials.

Gov. Kathy Hochul issued a warning Saturday to caution residents and said state officials are closely monitoring the forecast. “We stand ready to assist our local government partners in the event of additional flash flooding,” Hochul said in a statement.

On Long Island, the flood watch expires at midnight Sunday as lingering showers and thunderstorms fizzle out overnight. For the start of the workweek on Monday, mostly sunny skies and a high near 88 degrees are in the forecast with widespread haze as wildfires continue to burn in Canada.

“Some smoke in the upper atmosphere might work its way back into the area,” Wunsch said.

A chance for showers and thunderstorms returns Tuesday along with partly sunny skies and a high near 88.