Long Island weather: Highs around 70 for Labor Day weekend, forecasters say

On one of the biggest travel weekends of the year, forecasters say the weather will be generally pleasant and somewhat changeable.

The National Weather Service expects Long Island's Sunday and Labor Day to be fine barbecue weather: mostly sunny with highs hovering around 80. 

Before that, the region faces a modest chance of thunderstorms, 20-30%, both Friday and Saturday, consistent with a generally pleasant start of the unofficial arrival of autumn. Forecasters say the best chance of rain is overnight Saturday into Sunday. 

"It's on the cooler side through the Labor Day weekend with temperatures in the 70s," said Dominic Ramunni, a meteorologist with the weather service in Upton. "We're looking at a little unsettled weather Saturday with a few showers possible Saturday into Saturday night,"

But then conditions are expected to dry out, bringing a comfortable Sunday into Monday, with highs both days in the lower 80s.

For the legions of New Yorkers headed out of town, similar conditions are expected to the north for upstate New York and New England as well as westward into New Jersey, Ramunni said.

Millions of people will travel for the Labor Day holiday and heavy volume is expected on the metropolitan area's road beginning Thursday into Saturday

Nearly five million vehicles are expected to pass through and over MTA facilities from Thursday to Monday, a projected 3% increase from last year, according to AAA. Bridges and tunnels will see 60,000 crossings every hour between 3 and 6 p.m. Thursday and 2 and 6 p.m. Friday.

If last year's patterns hold true, the agency predicts the busiest bridge will be the Verrazzano-Narrows Bridge, bearing more than 1.1 million vehicles, followed by the Robert F. Kennedy Bridge at over 950,000 automobiles and the Whitestone at nearly 750,000 vehicles, authorities said.

The Transportation Security Administration expects to screen more than 17 million air travelers from Thursday through Wednesday, which the agency said will break previous Labor Day records, capping a historically busy summer.

The Port Authority of New York and New Jersey, which runs the region's largest airports, predicts a 3% increase from last year’s record-setting Labor Day travel, with approximately 2.5 million passengers traveling through Kennedy, Newark Liberty, LaGuardia and New York Stewart airports during the holiday period,

With Nicholas Grasso