Over the past few days, a deep trough has formed across the Central U.S. as the jet stream took a broad dip to the south. Dropping from the Northern Rockies to the Southern Plains and then northeastward across the mid Mississippi Valley, it has been directing storms along its path. Since the heaviest precipitation develops at and near the interface of cold, dry air and warm, moist air, the greatest impact of the trough has occurred along its southern margin.
As a result, heavy snow fell across eastern Texas, northern Arkansas and southeastern Missouri while areas to the north have received little precipitation. Though temperatures have been very similar, we have enjoyed partly cloudy skies in Columbia while St. Louis, 80 miles to our southeast, received ten inches of snow; even heavier amounts fell in the Ozarks of northwest Arkansas, well to our southwest.
After another blast of Canadian air tonight, the trough is expected to flatten out, the winter conditions will push off to the northeast and warm air will move in from the southwest. Just another round in the fickle month of March.
