Heavy snowfall and blizzardlike conditions are being reported as a powerful winter storm moves through the middle of Nebraska. The Nebraska Transportation Department closed Interstate 80 and U.S. Highway 30 in both directions Thursday morning, from Lexington to North Platte. It cited whiteout and other weather factors. The National Weather Service has posted blizzard or winter storm warnings for several counties. Most of the warnings are scheduled to expire by Friday morning. Six inches of snow was reported in Cozad and Elwood.