Nor'easter's rain, wind bring 'locally major' flooding to Nassau's South Shore, southwestern Suffolk; worst impact Sunday, Monday, NWS says

A nor’easter will batter Long Island with high winds, several inches of rain and coastal flooding, dampening hopes of those pining for a three-day fall weekend — not to mention Columbus Day paradegoers and those putting up early Halloween decorations — the National Weather Service has forecast.

The rain and wind could begin as early as Saturday evening, according to the weather service, but the most dangerous impacts will begin on Sunday.

The weather service issued a high wind watch from Sunday at noon through 6 a.m. Monday, according to the brief. The strongest gusts could blow at 60 mph Sunday afternoon and evening.

"The combination of the wet ground and the winds, especially since a lot of the trees still have leaves on them, we could see potential for trees and power lines to fall in the peak of the winds ... Saturday afternoon through Sunday night," meteorologist Brian Ciemnecki said late Friday. "Anyone that has their Halloween decorations out, those could obviously be ... blowing away."

The weather service has issued a coastal flood warning from noon on Sunday through 6 p.m. Monday for southern Nassau County and southwestern Suffolk County.

The agency advised residents that moderate widespread or "locally major" flooding could close roadways and flood lawns, basements and even the first floors of homes and businesses along the water.

Flooding could also extend inland along bays and rivers, and even to "some areas that typically don’t see flooding," the weather service’s Friday evening briefing on the storm reads.

Widespread beach flooding and dune erosion could occur during Sunday and Monday high tides, the National Weather Service said. Waves between 3 and 6 feet could impact the North Shore. Even taller waves could splash over and flood roadways and shoreline properties in Orient Point, the agency warned.

A total of around 1½ to 3 inches of rain will probably fall across the island between Sunday morning and Monday evening, according to an agency brief issued Friday evening. Localized flooding due to drainage issues is also likely.

In a statement issued Friday, Gov. Kathy Hochul urged "all New Yorkers to stay alert, watch the forecast closely, and take steps now to prepare.

"Conditions can change quickly, so please use caution if you need to travel and check on friends and neighbors who may need extra help," Hochul continued. "Staying vigilant and informed will help keep everyone safe through the weekend."

Fire Island Ferries service will be suspended from 1 p.m. Sunday through Monday, and the Fire Island Water Taxi will not offer transportation on Sunday and Monday.

The Village of Babylon announced residents can park in Babylon municipal lots should they wish to move cars from areas that might flood. Officials also encouraged boat owners to check boat lines and make certain everything is secure at their boat slip.