Heavy snowstorms, high winds and sub-freezing temperatures are ripping through the Mountain West, forcing road closures and other emergency conditions. Despite it being Mother's Day, up to 15 inches of snow is possible in parts of Colorado and up to ten in Denver. Virtually all of northern and northeastern Colorado are operating under winter storm warnings, with four separate interstate closures as of late and crashes around the area. Snow began to fall in Denver about 9:30 a.m. local time. By noon a foot of snow had accumulated in Colorado Springs, an hour south of the state capital. The extreme conditions are expected to last through noon in Denver, before moving onto Nebraska, Missouri and Iowa where tornadoes will likely form from the pressure system.