Better have your rain gear handy, as heavy precipitation is expected to impact the area Thursday night right through the Friday morning commute, forecasters say.

In a hazardous outlook, the National Weather Service warns of the possibility of heavy rain late Thursday and into Friday that could bring about the chance of flash flooding, as well as areal flooding, which is a more gradual buildup of water from prolonged rainfall, mostly in low-lying and flood-prone areas.

Rain is increasingly likely to start spreading across the Island from west to east by around sundown Thursday, becoming widespread by midnight, said Jay Engle, weather service meteorologist in Upton. The bulk of the precipitation was expected to fall from midnight through late morning Friday, he said, when there’s also potential for isolated thunderstorms.

Friday afternoon and night bring a slight chance for scattered showers, the weather service said. Highs for the day are forecast for the upper 70s to around 80 degrees.

Looking ahead, it’s shaping up to be a “50/50 weekend,” said Rich Hoffman, News 12 Long Island meteorologist.

Saturday brings unsettled conditions with a slight chance of showers and highs heading up to the mid-80s, the weather service said.

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Sunday’s looking to bring sunny skies, with highs in the low 80s — “beautiful,” Engle said.

Conditions Monday are expected to be similar, with mostly sunny skies, according to the Thursday afternoon forecast.

If that holds, it means commuters will be catching at least one break on the first day of a temporary reduction in rush-hour service on the Long Island Rail Road, brought about by Amtrak repair work at Penn Station. The work is scheduled to continue through Sept. 1.