* WHAT. Heavy snow expected. Total snow accumulations of 6 to 14 inches. Winds gusting as high as 40 mph. * WHERE. Upper Kobuk Valleys. * WHEN. Until 5 AM AKDT Tuesday. * IMPACTS. Travel could be very difficult to impossible. Areas of blowing snow could significantly reduce visibility. * ADDITIONAL DETAILS. Rain will mix in at times, creating wet and dense snow. * IMPACTS. Travel could be very difficult to impossible. Areas of blowing snow could significantly reduce visibility.