Brothers Giovanni Giua, 5, right, and Edoardo, 5, of West...

Brothers Giovanni Giua, 5, right, and Edoardo, 5, of West Islip, play in the sand at field 5 at Robert Moses State Park, May 26, 2011. Credit: James Carbone

You might wake up to warm, sunny skies this weekend. But if you're headed to the South Shore beaches, don't believe your lying eyes, because the weather there will likely be cloudy and cooler, forecasters at the National Weather Service said.

While temperatures inland are expected to be in the high 70s or even low 80s Saturday, Sunday and Monday, beachgoers can expect weather that is about 10 to 15 degrees cooler, Upton-based weather service observation program leader Tim Morrin said Friday.

"You're probably going to get to the barrier bridges thinking it's a beautiful day," Morrin said. But those temperatures coupled with winds out of the south of 8 to 12 mph and gusts of up to 15 mph means you may need a jacket, he said.

Also, the water will be about 60 degrees, perhaps cooler, and there is a moderate risk of rip currents along the South Shore throughout the holiday weekend, Morrin said.

"You're probably not going to want to go in the water," he said.

The winds, caused by a high-pressure system offshore -- "a classic summertime Bermuda high," Morrin said, may cause low-lying clouds and fog to impact the Bethpage Air Show at Jones Beach on Saturday and Sunday.

Morrin said "it's very possible" the weekend weather along the shore will have "gray-slate clouds, stratus clouds, at an average height of 700 or 800 to about 1,200 feet," he said.

Daily forecasts for the weekend call for partly cloudy to mostly sunny weather, the service said. After dark, expect partly cloudy weather, with lows ranging between 62 and 66, the service said.

For those taking an extended weekend, Tuesday's high will be 83 under mostly sunny skies, forecasters said. Rain enters the picture Wednesday with a chance of afternoon precipitation.

With Gary Dymski

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