Heavy rains flooded streets on Long Beach Road between Sunrise...

Heavy rains flooded streets on Long Beach Road between Sunrise Highway and Merrick Road in Rockville Centre on Sunday afternoon. Credit: Jim Staubitser

Long Island residents shouldn’t plan on putting their umbrellas away just yet, with scattered showers forecast for Monday and Tuesday, according to the National Weather Service in Upton.

“It’s just an unstable environment and because it’s just been so humid, there’s just been a lot of water,” said weather service meteorologist Carlie Buccola.

The rain, which fell over the weekend, will continue into the beginning of the week across Nassau and Suffolk counties, due to a stalled weather front to the south, Buccola said.

Heavy downpours can crop up, but it’s difficult to pinpoint exactly where or when, she said.

The showers could lead to flooding over the next two days, particularly on the South Shore of Nassau County, as well as some places on the North Shore of Suffolk County, like Northport, said News 12 Long Island meteorologist Pat Cavlin.

“Any of these showers and thunderstorms have the potential to produce localized flooding, because they’re slow-moving and they’re going to be producing heavy rainfall,” Cavlin said, adding that the ground already is saturated in many areas.

The weather service Sunday afternoon had canceled a flash flood warning for western Suffolk County and southern Nassau County.

Westhampton, Beach, Mastic Beach and Center Moriches in Suffolk County saw flash flooding Sunday morning, according to reports on the weather service website. Reports from Mastic Beach included 2.79 inches of rain as of 8:24 a.m.

There were several incidents of flash flooding Sunday afternoon in Nassau County, including North Merrick, East Meadow, North Bellmore, and Bellmore, according to reports on the weather service website. The flooding caused road closures in several areas.

At 1:20 p.m. there were reports of 2.05 inches of rain falling within 40 minutes in North Bellmore, leading to major flooding and fire rescue responding to multiple rescues from vehicles, according to the weather service.

Elsewhere in Nassau County, Hicksville saw 1.48 inches of rain by 1:46 p.m. Sunday, and Uniondale had 1.39 inches as of 1:36 p.m., according to the report. Other areas including Port Washington, Locust Valley and Matinecock had more than an inch of rain as of Sunday morning, according to the report.

A flood advisory remained in effect in southeast Nassau County through 12:30 a.m. Monday, according to the weather service.

Rain that has made for a soggy Long Island summer has continued into August, with 3.42 inches recorded so far at Long Island MacArthur Airport, Tim Morrin, a meteorologist with the weather service's Upton office, said Sunday afternoon. The average rain total for the entire month is 3.98 inches, he said.

The storms shouldn’t impact the Monday morning commute, with showers likely to be on the lighter side, Cavlin said.

Temperatures are expected to be in the low 80s Monday and Tuesday, and sunny weather is predicted for Wednesday, when temperatures could reach the upper 80s to near 90 degrees, Cavlin said. “The middle of the week will dry things out.”

With Rachel Uda

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