Some cold fronts sweep into the Midwest behind potent storm systems, as strong, northwest winds develop behind an energized low; in these cases, destructive thunderstorms often precede the front while heavy snow and blizzard conditions develop to its west. Other cold fronts, usually dropping south from the Canadian Plains, arrive with barely a whimper as dense, frigid Arctic air flows through the Heartland like a slow, broad river. Often nudged from the North Pole by a developing ridge over Alaska and western Canada, the dome of cold, dry air funnels southward between the High Plains and the Appalachians, with the most frigid air settling across the Upper Midwest.
Record low temperatures had developed across Minnesota and the eastern Dakotas this morning (as the center of the dome crossed into the U.S.) and extreme cold is forecast for most of the Midwest throughout the coming week; the leading edge of the cold air, moderating as it flows to the south and east, will bring a hard freeze to the Gulf Coast and northern Florida over the next few days.
Since the cold, dense air behind these Arctic fronts is usually rather shallow, the higher terrain of the High Plains and Front Range often escapes the most severe air, which drains southward through the Missouri and Mississippi Valleys. Today, Denver, Colorado, will be in the 40s(F) while here in Columbia, Missouri, we'll top out in the mid teens (after an overnight low of zero).
