Long Island forecast: Rain, flooding possible

The National Weather Service has issued a series of coastal flood advisories through Friday for Nassau and southwest Suffolk counties as well as parts of Queens.

Similarly, the Town of Riverhead issued a statement Thursday advising residents of possible inundation of vulnerable areas near the waterfront — in effect until 2 p.m.

The weather service also warned of dangerous rip currents through Friday evening, with the most dangerous areas along Suffolk's ocean shorefront.

There's also a chance of rain in the mix, though the weather service said any precipitation will likely be localized on the East End, with much of Nassau and Suffolk spared — though the risk of showers will increase Friday, when much of the Island could see some rainfall.

"It doesn’t look like a ton of rain either day," said Dominick Ramunni, a meteorologist with the weather service's Upton office. "But given how dry it’s been over the last week or so, any type of rain like this is certainly welcome."

Regardless of rain totals, the flood risk will remain, coming two nights after a full moon.

"This is being driven by high astronomical tides," Ramunni said. "And couple that with persistent onshore flow from a weak area of low pressure offshore, which basically helps pile the water a little bit higher than it normally would be, and we’ll see some minor inundation of typically dry ground."

The weather service warned early Thursday of the widespread minor-to-localized flooding as a result of a 1-to-2 foot inundation of vulnerable coastal locales due to those tides.

A coastal flood statement warned of the potential for brief minor flooding in southeast Suffolk, Nassau and Queens, in effect from 10 a.m. to 2 p.m. Thursday. There also is a substantial risk of flooding in vulnerable areas in Manhattan, Brooklyn and Staten Island, the weather service warned, with a coastal flood advisory in effect throughout much of the morning — as well as from 8 to 11 p.m. Thursday.

Those risks also figure to play out again on Friday, the weather service said, with coastal flood watches in effect for Nassau and Queens.

"Minor to localized moderate coastal flood impacts remain possible through the weekend," the weather service said Thursday, warning of "multiple rounds" of coastal flooding through Friday at the very least.

Residents of "the most vulnerable coastal locals" along the South Shore bays and the western portion of Long Island Sound can expect up to about a foot of coastal flooding, Ramunni said.

He added that coastal flooding is also not out of the question this weekend.

"Our forecast at this point has the flooding continuing for cycles thereafter," he said. "So an extension is very likely at this point beyond just tomorrow."

The weather service is warning of dangerous rip currents along the South Shore in Suffolk, with life-threatening rip currents likely for anyone entering the surf zone.

A small craft advisory is in effect for the Long Island Sound, New York Harbor, Peconic, Gardiners and other South Shore bays from Jones Inlet to Shinnecock Bay through Friday at 6 a.m.

A gale warning is in effect for all ocean waters from Sandy Hook, N.J., to Montauk Point.

With Nicholas Grasso

By John Valenti

john.valenti@newsday.com

John Valenti, a reporter at Newsday since 1981, has been honored nationally by the Associated Press and Society of the Silurians for investigative, enterprise and breaking news reporting, as well as column writing, and is the author of “Swee'pea,” a book about former New York playground basketball star Lloyd Daniels. Valenti is featured in the Emmy Award-winning ESPN 30-for-30 film “Big Shot.”