"Excessive rainfall" throughout Saturday could lead to flooding and related storm damage for Long Island, the National Weather Service said.

Friday afternoon revision of rainfall predictions, the weather service said Long Island could see up to 2½ inches total, with lower amounts predicted for the East End. The weather service said the lower Hudson Valley region could see up to 3½ inches of rain.

Long Island could get up to 3½ inches of rain if the storm shifts, the weather service added. The forecast calls for rain beginning 2 a.m. Saturday.

"There is an increasing potential for flooding … " through late Saturday night, the weather service alert stated. "Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas."

The timing of most of what is now projected as potentially "excessive" rainfall will be Saturday afternoon into Saturday night.

Making matters worse is the potential that strong, gusting winds could lead to downed trees and power lines, with saturated soil from the rain playing a factor.

What is being called "a blustery, north wind" of 16-23 mph is expected later on Saturday — with gusts as high as 45 mph, the weather service said.

Wind chill values will make it feel as if it's between 20-25 degrees outside.

A flood watch is in effect for all of Long Island from Saturday morning through Saturday night.

A gale watch also is in effect for Long Island Sound east of Port Jefferson, as well as for all South Shore inlets, bays and ocean waters — and will remain in effect from Saturday morning through Sunday afternoon. "Strong winds can cause hazardous seas which could capsize or damage vessels and reduce visibility," the weather service said in an alert. "Mariners should consider altering plans to avoid possible hazardous conditions."

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 5 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME