Strong thunderstorms moving over Suffolk Tuesday evening may bring 50 mph wind gusts and "torrential rains," the National Weather Service said.
More than 2 inches of rain per hour may fall from the storm, and frequent cloud-to-ground lightning is expected, meteorologists at the Upton-based service said.
The line of heavy showers and thunderstorms has been moving across Suffolk at 15 mph, the service said, and may cause localized flooding in areas with poor drainage.
Meteorologist Joe Pollina said most areas won't see prolonged bouts of rain from the storm: "It's not really hanging around."
A flood advisory will remain in effect for eastern Suffolk County until 9:15 p.m. Tuesday, the service said.
The wet weather comes "as a weak low pressure and an associated warm front lift northward into the region," the weather service said.
Minor coastal flooding is possible again Tuesday night near the time of high tide along western Long Island Sound, forecasters said.
Tides of a half foot to 1 foot above normal are anticipated.