The National Weather Service has put Long Island under a tropical storm warning, forecasting that the system known as Fay is coming up the coast with downpours and gusty winds through Friday and Saturday.
"We will have heavy rain between 1 and 3 inches with locally higher amounts possible; that is the primary hazard," said NWS meteorologist Da'Vel Johnson of the Upton office. There will be sustained winds of 30-35 mph and gusts of up to 50 mph, he said.
The service expects the storm to affect the area from 6 a.m. Friday though 2 a.m. Sunday, he said.
The NWS storm warning said in an email: "the main threat with this system will be locally heavy rainfall and potential for flash flooding Friday into Friday night."
Long Island is also under a flash flood warning.
"It's going to be a lot of rain, a lot of wind … those are the main concerns," Johnson said. The accompanying high surf and rip currents will mean "any beachgoing is definitely not a good idea."
This is the first tropical storm warning of the season for Long Island, he said.
The system could include quick-moving and severe thunderstorms and the "low potential" for damaging winds or tornado, the weather service said.
Elizabeth Flagler, a spokeswoman for PSEG Long Island, said company officials were monitoring the forecast Thursday night and said employees “are always prepared to work 16-hour shifts.”
She said a more detailed plan will come together if a storm does materialize sometime Friday.
“We’ll have people on standby and ready to respond. We’ll have a full complement ready and prepared to deal with any challenges that might come with the heavy rain and wind.”
Nassau County Executive Laura Curran put out a statement Thursday evening warning residents about the story and telling them to prepare for emergencies. She said the county's office of Emergency Management would be in touch with PSEG, police and other first responders during the two-day storm.