Long Island weather: Sunshine Friday, then heat

The weekend looks promising, starting with Friday, when sunshine and highs in the low 70s are predicted. On Saturday and Sunday temperatures are expected to get into the mid-80s, Joe Pollina, meteorologist with the National Weather Service in Upton said.

But before then, Friday looks great.

"Friday we're looking at warmer conditions than today but not nearly as warm as it will be over the weekend," Pollina said Thursday evening. "Highs in the lower 70s for much of the Island, the Twin Forks and immediate shore may remain in the mid to upper 60s on Friday."

Friday night there is a small chance of rain and thunderstorms, the weather service said.

"On Saturday is when we'll start to see heat come into the area, it won't be as warm as the city or New Jersey but it will be warm for this time of the year," Pollina said. "We're looking at highs in the middle 80s for much of Long Island and near the coast, shoreline and Twin Forks conditions will be cooler."

He said Sunday will be slightly cooler than Saturday, in the upper 70s and lower 80s, maybe in the middle 80s for northern Nassau County.

Pollina said a high-pressure system will build in the area Friday and push south and set up a southerly flow across the area.

"That will bring the heat and humidity over the weekend," Pollina said. 

Meanwhile, the first widespread 90 degree temperatures and heat indexes of the season are expected this weekend in New York City, according to the National Weather Service there.

Rain is possible Monday, but the day should otherwise be cloudy. Highs in the mid-70s are predicted. There is a chance of rain that night as well.

Tuesday will also be cloudy and even cooler, with highs in the upper 60s predicted. There could be rain that night, the weather service said.

Showers are also possible Wednesday, and highs should again be in the upper 60s, the weather service said.