A blanket of snow hit the McHenry County area overnight Sunday and Monday morning. A winter weather advisory is in effect through 2 p.m. Monday, according to the National Weather Service. Between 3 inches and 6 inches could accumulate throughout Illinois, according to the service. Area law enforcement are encouraging care on the roads for those who are traveling. Illinois Department of Transportation is charged with salting and plowing state roads, including Routes 176, 23, 47, 14 and 31.