Long Island weather: Clear night ahead before unsettled midweek

A clear night is in store Tuesday, the first of two days of sunshine and comfortable temperatures before unsettled weather moves in, meteorologists said.

Nighttime lows will range around the low 60s on Tuesday and Wednesday, with highs in the mid 70s and blue skies. Then it turns wet Wednesday overnight into Thursday and cooler with the arrival of fall, the weather service said.

The odds of showers and storms are low overnight Wednesday but rise to 80% Thursday.

The rain, though welcome because the Island remains in a severe drought, may only add up to a quarter of an inch of precipitation. Isolated thunderstorms, however, might produce more rainfall. 

A high for Thursday of 74 degrees is anticipated, but then the mercury drops.

"The main story later in the period will be the autumn-like temperatures for Friday and the first half of the weekend with Canadian high pressure building in. Temperatures on Friday are expected to only reach the 60s regionwide. Saturday will be a few degrees warmer, but still slightly below normal, with highs in the upper 60s to lower 70s," the weather service forecast said.

And there is a high risk of dangerous riptides and "energetic swells" from Wednesday night through Friday due to Hurricane Fiona, which has been deluging the Caribbean and is expected to move north. 

The weekend appears otherwise promising, with sunshine predicted from Friday through Sunday, due to a cloud-erasing high pressure system and temperatures rebounding somewhat to the low to mid 70s.

A warm front might dampen Sunday night, when there is a 30% chance of showers.

On Monday, the downpour odds climb slightly to 40% as a cold front reaches the Island. Highs should be in the mid-70s.