Better get the rain gear handy.
"There's a growing potential for a heavy rainfall event, probably late Friday into early Saturday," said Joey Picca, meteorologist with the National Weather Service, based in Upton.
Light to moderate rain could develop later Thursday into Friday morning, out in front of what the weather service calls "a more significant low moving up the coast from the eastern Gulf of Mexico" that "could produce several inches of rain" overnight Friday.
As of Wednesday afternoon, there was "still quite a bit of uncertainty in both timing" and location of the heaviest rainfall, Picca said.
At play is a low pressure area moving from the west and across the central United States, that is expected to "tap into the moisture of the tropical system" moving up the coast, Picca said.
Most of Thursday looks to be dry, including the evening commute time, with light to moderate rainfall starting later in the evening, said Lauren Nash, also a meteorologist in Upton. The weather service site indicates from "a tenth and quarter of an inch possible."
Friday during the day is expected to be "unsettled," Picca said, with an 80 percent chance of precipitation and from a half- to three-quarters-of-an inch of rain possible.
Overnight Friday, however, could bring possible new rainfall of 2 to 21/2 inches, the weather service said.
Bill Korbel, News 12 Long Island meteorologist, said Wednesday afternoon he's looking at from about noon Friday to sunup Saturday for the heavy rainfall.
Depending on the storm's track, Long Island "could see upwards of two or more inches of rain," he said, and with the ground already saturated, that could cause local street and highway flooding, but not coastal flooding.
Of course a shift in track of "100 miles one way or other," could cut that rainfall amount in half, he said.
As of Wednesday's forecast, the heaviest rain is expected to have moved out of the area by Saturday morning, but look for "possible lingering rain throughout the day," Picca said.
The one hope for the weekend? Sunday, which should be partly cloudy, with highs in the 70s, and just a 20 percent change of precipitation, he said. That looks like "the best day -- at the moment," Picca said.