A line of strong thunderstorms has moved southeast over Long Island and brought torrential rainfall Thursday night to much of Nassau and western Suffolk, the National Weather Service said.

The front will dissipate or move off by 8 p.m. and may bring pea-sized hail, localized flooding and wind gusts of up to 40 mph, according to the service’s Upton office.

The North Shore may be deluged early in the night and experience localized flooding under storm clouds that aren’t going to be passing through quickly, said NWS meteorologist Jay Engle.

The clouds may hit as far east as Commack and Brentwood, meteorologists said.

“They’re not moving very quickly,” Engle said. “They tend to move 10 to 15 miles per hour and a lot of times thunderstorms move 30 to 35.”

As another sign of the day’s volatile weather, a storm cell appeared to be forming over Garden City shortly after 6:30 p.m., he said.

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This comes after a Long Island forecast of storms, lightning, gusty winds and a flash flood warning, which expired at 6 p.m. Much of that did not materialize.

“These storms have been what we would call pulse-y,” Engle said. “They don’t seem to hold together for more than 20 minutes at a time.”

An air quality alert remains in effect for the region until 11 p.m. Friday.

Engle said the Island needs the rain because it is in a moderate drought.

Earlier Thursday, News 12 Long Island meteorologist Rich Hoffman said that the humid air mass hovering over the area could generate heavy rainfall.

As of around 3 p.m., the temperature at Long Island MacArthur Airport was 85 degrees, but felt more like 93, thanks to the humidity.

Friday morning conditions could include patchy fog, the National Weather Service said.

Hoffman said that temperatures through Saturday will be higher than normal. There’s also a chance for another round of showers and heavy rain, starting Friday night and lingering into Saturday, the service said.

With Patricia Kitchen and Gary Dymski