Long Island weather: Sunny, with summer-like temperatures

Get out the short sleeves: unusually warm and sunny will describe Wednesday’s weather, the forecasters said.

While the National Weather Service does not predict any record high temperatures being set, daytime highs should spike about 15 degrees above normal, reaching the upper 80s to 90 in New York City "and points north and west," it said.

"To the east, highs will generally be in the lower to mid-80s, except the upper 70s across the Twin Forks and South Shore barrier islands of Long Island," the weather service said.

Wednesday's low humidity is another element of the forecast.

The weather service said: "Northerly winds across the area today will keep a dry air mass in place that will heat up very quickly this morning."

And aside from a stray shower or thunderstorm that may arise from Thursday to Saturday, at least partly sunny skies are forecast through next Tuesday, with one exception: Saturday may be mostly cloudy, according to the weather service.

Summer warmth in May

The early summer-like warmth should be confined to Wednesday, though Sunday will see a daytime high of 82 degrees, the weather service said.

Otherwise, daytime highs in the low 70s with night time temperatures mainly sticking to the mid-50s are predicted through Tuesday.

All this fine weather results from a high pressure system building across the eastern United States, the weather service explained.

Blue skies usually appear with these systems because their rising air cools and dries, preventing clouds from forming. Rain develops in low pressure systems because vapors condense as the warm air rises.

Between that high pressure system and a low pressure system in the south and east of the Canadian Maritimes and across the western Atlantic, a cold front will slip into the Island late Wednesday afternoon.

The cold front will bring light winds but, the weather service said, "there could be brief surge (10 to 20 mph) of stronger winds right behind the front with a cooler maritime air mass."

So look for Wednesday’s night time low temperatures to run from the low to mid-50s in outlying areas, to the low 60s across metropolitan New York and New Jersey, the weather service advised.

Thursday will not be nearly as warm. The weather service said temperatures should range about 10 degrees cooler than on Wednesday.

So look for highs in the 70s along the coast, in the 60s on Long Island’s South Shore, and in the low 80s across the lower Hudson Valley and New Jersey’s interior, the weather service said.

"Temperatures will warm just a bit on Friday as the air mass modifies and the flow becomes southerly," the weather service said.

Temperatures during the day may top out at 70 degrees on Friday, reach 75 on Saturday and 82 on Sunday.

After a cold front travels through the tri-state area, the weather service predicted, "temps should briefly cool off on Monday, with highs from the upper 60s to mid-70s."

Tuesday should be sunny with a similar high on Long Island. Thanks to a warm front, though, it may well be as much as 10 degrees warmer in northeast New Jersey and the lower Hudson Valley.