New Brunswick, Matawan, and Edison were among the areas hit hard.
Police in Keyport say there were multiple road closures due to flash flooding.
New Jersey Gov. Mikie Sherrill released a statement warning residents not to drive through flooded streets:
"Parts of the state are under a Flash Flood Warning through this evening's commute. Most flood deaths occur in vehicles. Please plan ahead, stay safe, and do not drive through flooded areas."
Streets in Matawan began to flood in the afternoon and cars were submerged in water.
Streets flood in Matawan, NJ during flash flood warnings Thursday
Major flooding closed 3 lanes of US 1 southbound, south of Plainfield Avenue in Edison, NJ.
Cars drive through waves of water on Route 1 in Edison, NJ
Several cars in New Brunswick tried to drive through flooded streets and got stuck in the high floodwaters.
Cars stuck in high floodwaters in New Brunswick, NJ
Meteorologist Jeff Smith says there is a potential risk for scattered thunderstorms on Friday, with downpours possible.
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