High water closed Route 1 in both directions between Bethany Beach and Dewey Beach, DelDOT reported. Numerous other roads also were closed.
Southern Kent County received more than 5 inches of rain, and totals in New Castle County ranged from about an inch in the northern rim to over 2 inches at Blackbird for the past 24 hours as of 8 p.m. today.
The weather service issued a flash flood watch statewide through Friday afternoon.
In Sussex, several school districts announced delayed openings for Friday.
The wind gusted to 42 mph at Indian River Inlet, and the weather service said more strong gusts are expected overnights.