The National Weather Service says parts of South Jersey could see 1 to 3 inches of snow before the storm moves off the coast Thursday night.
With temperatures below freezing, the coating of snow caused very slippery conditions on the roads, and police reported numerous accidents. There were no immediate reports of fatalities.
The New Jersey Turnpike reduced its speed limit to 45 mph from Exit 7 at Bordentown to the Delaware Memorial Bridge.
The Delaware River Port Authority reduced speeds to 35 mph on its four Philadelphia-area bridges.
Forecasters expected the snow to taper off during the evening and end by 10 p.m.