An intense but brief thunderstorm swept across much of Long Island late Thursday afternoon, bringing frequent cloud-to-ground lightning, the National Weather Service said.

The storm moved east at 50 mph, packing 60-mph wind gusts, the service said.

There’s a mostly 30 percent to 40 percent chance for isolated or scattered showers and thunderstorms for Long Island through the overnight hours, forecasters said.

Meanwhile, afternoon flight arrivals at Kennedy Airport were averaging delays of close to two hours — and an hour and a half for LaGuardia — as a result of weather conditions, according to the Federal Aviation Administration’s website. Some departures were also being affected, the FAA said.

As about 2 p.m., the temperature at Long Island MacArthur Airport was 83 degrees, and felt more like 90, thanks to the humidity. Farmingdale was registering 84, feeling more like 93. Those numbers were 81 and 87, respectively for Shirley.

The warm front that brought the rain was accompanied by a low pressure system that will remain along the mid-Atlantic and help keep conditions warm and humid.

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With an elevated level of ozone expected, an air quality alert has been issued and is in effect for Friday from 11 a.m. to 11 p.m. Those who are very young and those with respiratory problems may be especially sensitive to the increased levels of the pollutant.

News 12 Long Island meteorologist Bruce Avery described the next few days as “classic summer weather.”

Avery called for hazy, very warm and humid conditions ahead, with highs mostly in the mid-80s.