NEW YORK, Aug 23 : Hurricane Henri kept on track to wreak havoc on New York early Sunday — but early downpours had already sparked major flooding in the Big Apple by Saturday night, shuttering subways and inundating roadways.

The tempest was on course to make landfall on Long Island or in southern New England by midday Sunday, according to the National Oceanic and Atmospheric Administration.

But storms caused in part by moisture from Henri hit the region late Saturday bringing heavy rains and flash floods to New York City, and even forcing drivers out of their cars in Brooklyn.

Photos captured by The Post in Gowanus showed police and firefighters assisting drivers whose cars appeared to be completely stuck in more than six inches of water.

Twitter users also reported flooding in Williamsburg, as drivers navigated streets-turned-rivers by the earlier than expected rains. The deluge, along with lightning, brought the star-studded We Love NYC Homecoming concert in Central Park to a halt at around 7:30 p.m. The highly anticipated event was officially canceled about two hours later.