Lifeguards at Smith Point County Park in Shirley get some...

Lifeguards at Smith Point County Park in Shirley get some fitness training done, Tuesday. (May 25, 2010) Credit: John Dunn

An overcast day on Long Island may lead to thunderstorms Thursday afternoon, but the good news is forecasters are calling for mostly clear skies this Memorial Day weekend.

A "backdoor cold front" -- a system that moves southwest instead of east like a regular cold front -- will bring cooler temperatures to Long Island and perhaps some rain, said Joe Pollina, meteorologist with the National Weather Service in Upton.

Highs Thursday should be around 70, with lows Thursday night in the mid 50s.

A Coastal Flood Advisory also is in effect from 7 p.m. to 10 p.m. due to a "combination of  astronomically high tides and long period southeasterly swells hampering tidal drainage."

Islip hit 92 degrees at 3:56 p.m. Wednesday, breaking the previous daily mark for the date of May 26 -- 86 degrees -- set in 2007.

As for the holiday weekend, temperatures should stay in the 70s across the Island, with mostly clear skies, Pollina said.

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Wild weather on LI ... Deported LI bagel store manager speaks out ... Top holiday movies to see ... Visiting one of LI's best pizzerias ... Get the latest news and more great videos at NewsdayTV

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Wild weather on LI ... Deported LI bagel store manager speaks out ... Top holiday movies to see ... Visiting one of LI's best pizzerias ... Get the latest news and more great videos at NewsdayTV

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