PHILADELPHIA — A storm stretching from northern Texas to southern New England threatened to bring icy rains, sleet, and snow overnight Wednesday but also hopes it would be the last significant snowfall for the East Coast this winter.

Governors in Alabama, Mississippi, West Virginia and New Jersey declared states of emergency in advance of the storm, and Congress hurried to finish business amid a snow emergency declaration in Washington. Mississippi counties were advised to open shelters powered by generators to give residents an option beyond cold, dark homes in the event of power outages.

West Virginia, Kentucky and southeastern Ohio were expected to get hit the hardest overnight Wednesday and into Thursday with 8 to 10 inches, while Baltimore and Washington were looking at 6 to 8 inches of snow, said National Weather Service forecaster Bruce Terry.

Philadelphia, where a snow emergency was in effect Wednesday, could get 6 inches and New York could see more than 4.

Temperatures plummeted as the storm pushed east: The mercury fell from 71 degrees to 52 degrees in Monticello, Arkansas, and from 74 to 48 in Greenville, Mississippi — both within an hour. By Wednesday afternoon, readings were in the mid-20s across Arkansas.

Boston is a little more than 2 inches shy of its all-time snowfall record, and meteorologists predicted 1 to 2 inches would fall by storm’s end Thursday evening.

Schools from Texas to West Virginia closed early Wednesday and Penn State University canceled classes due to weather for the first time in eight years. About 1,200 flights were canceled, including 600 in and out of Dallas-Fort Worth.

Residents of Kentucky and West Virginia contended with flooded roads and mudslides. And by Wednesday night, a sheet of ice coated the roads in Memphis, Tennessee, making driving especially hazardous.