With an eye to the long holiday weekend, Long Island’s pretty much ideal weather is looking to give way about halfway through, forecasters say, as the potential for two rounds of heavy rain enters the picture.

As well-above normal temperatures in the 70s continue, forecasters are also pointing to the potential for an inch or 2 of rain Sunday night into early Monday — Columbus Day.

advertisement | advertise on newsday

Sunday starts out with a slight chance of showers, increasing later in the afternoon, with precipitation likely at night, according to the National Weather Service.

That precipitation would result from “moisture from tropical storm Nate” potentially interacting “with a stationary front just northwest of the local area,” according to a briefing issued Friday by the weather service’s Upton office. The precise timing and areas seeing heaviest rainfall were yet to be determined, given the uncertainty over Nate’s track and the position of the front.

Nate, now in the western Caribbean and heading for the Gulf Coast, looks to be threatening coastal areas from Louisiana to the Alabama-Florida border, according to the National Hurricane Center.

Based on the Friday evening forecast, after chances of showers, a second batch of heavier rain could be arriving Monday evening and lasting overnight into early Tuesday, said Faye Morrone, weather service meteorologist in Upton. That would be courtesy of the approaching remnants of Nate.

advertisement | advertise on newsday

With all that, there’s a chance for urban flooding of low-lying and poor drainage areas, the weather service said.