The National Weather Service issued a flood watch in Bergen and Passaic counties in effect from 8 a.m. Thursday morning until 2 p.m. on Friday.
Thunderstorms and between two and four inches of rain are expected, area meteorologist Joe Cioffi reports.
The saturated ground would mean local small stream, urban, and river flooding is likely, he said.
Friday will bring leftover clouds and passing showers, with temperatures in the 50s, Cioffi said.
"A big warm up gets underway on Sunday with sunshine and highs in the 60s," he added. "Monday into Wednesday of next week we will see sunshine and temperatures in the 70s in many areas."