A severe thunderstorm warning is in effect Wednesday night for eastern Nassau and well into Suffolk that could bring hail and winds as high as 60 mph, the National Weather Service said.
"An approaching cold front will bring potential for isolated to scattered strong to severe thunderstorms this evening," the weather said in a statement on it's website. "Strong to damaging wind gusts will be the main threat."
The storms should weaken, however, as they travel across Long Island and eastern Connecticut, the weather service said.
While Thursday should be sunny and clear, storms may bedevil Memorial Day celebrations, with rain likely Friday afternoon and Saturday morning.
Thursday should be nearly ideal: sunny with a high near 81 degrees.
Friday should start off just fine.
"Cooler and drier weather behind the (cold) front will then overspread the Great Lakes and the Northeast into Friday morning," the prediction center said.
Yet the odds of drenching rain arriving after midday are 50% and it will be much cooler, with a top daytime temperature of 67 degrees, according to the weather service.
The Ohio Valley will be delivering a low pressure system to the south and east of the tristate region Friday night and into Saturday, the weather service explained.
"This will be the first widespread rainfall event across the area since May 9-10," the weather service cautioned.
From half an inch to 1½ inches of rain may fall, and there may be minor to moderate coastal flooding across the western Great South and Jamaica bays during high tides on Friday night and possibly Saturday night too.
"At this point, dune impacts should be limited to localized and minor," the weather service said.
Saturday morning likely will start with rain, mainly before 9 a.m. The odds of showers are 70%, and the daytime high will be 64 degrees.
The weather service said its models now predict "conditions drying out Saturday morning," but there is another possible low pressure system that could run along the coast from Sunday and Monday.
Right now, Sunday looks like it will offer partly cloudy skies, with a high of 67 degrees.
Monday’s Memorial Day could be a winner, with mostly sunny skies with a high of 71 degrees.
The workweek resumes Tuesday with sunshine and just slightly warmer temperatures.