Saturday, February 17, 2007

Alberta Clipper

Alberta Clippers are relatively compact, high energy storms that drop down from central Canada and then race across the eastern U.S. Dragging a cold front with them, they usually produce high winds and brief, heavy snow. As they move eastward, backside flurries and strong, northwest winds can produce ground blizzards. However, unlike the big storms associated with Arctic and Pacific fronts, the clipper episode is usually over within 6-12 hours.

Clippers often develop rapidly and are thus hard to forecast. We had expected our first warm day in 6 weeks yesterday, awaking to cold sunshine and light winds. Turning on the tube, we were a bit dismayed to learn that an Alberta Clipper was diving southward through the Dakotas, heading our way. By noon the clouds were moving in and cold winds picked up from the west. A full-fledged snowstorm struck by early evening, producing high winds and a three-inch snowfall. Flurries and gusty winds were still around this morning but, by noon, the sun was breaking through and the clipper had moved on to the Tennessee Valley.