(AP) -- South Carolina is recovering from a winter storm that dropped up to 9 inches of snow in parts of the state, but officials warned there are still icy spots on roads.

The Department of Transportation said Wednesday all interstate highways are open and most are dry.

Spokesman Pete Poore (Pour) says water on the roads froze in some areas, causing dangerous patches. Most of the problems are reported northwest of a line from Edgefield to Chesterfield.

The National Weather Service issued a winter weather advisory until noon Wednesday for the northwestern corner of the state because of icy travel conditions.

Schools remained closed across much of the northwestern half of the state.

Duke Energy had fewer than 50 customers without service in South Carolina, most in Greenville County.

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