UNDATED, Ala. More than three dozen school systems closed early today in north Alabama, postponing athletic events and at least one prom, as severe weather moves into the state.Forecasters have issued a tornado watch for northwest third of Alabama, and the weather service said powerful thunderstorms and twisters, gusty winds and hail are possible through the night. Weather Service meteorologists at the Huntsville office say eight counties are under a tornado watch until 8 p-m. They are: Cullman, Morgan, Limestone, Madison, Colbert, Lawrence, Franklin and Lauderdale.Schools as far south as metro Birmingham began dismissing students as early as noon. Baseball games were called off, and Hillcrest High School near Tuscaloosa delayed its junior-senior prom from Friday until tomorrow (Saturday) night. Copyright 2006 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.