Extratropical Lows - Clippers

Sea Level Pressure and Temperature during an Alberta Clipper: Early on 19 December an Alberta Clipper cyclone with central pressures of 1008mb is present. The cyclone intensifies briefly and then migrates eastward across the Great Lakes during 20 to 22 December. Surface temperatures dropped to -20° F immediately after the passes of the low resulting in a brief cold outbreak over the Dakotas, Minnesota, and Wisconsin. Courtesy of Dept. Atmospheric Sciences, University of Illinois at Urbana-Champaign
National Radar during an Alberta Clipper: Precipitation associated with an Alberta Clipper develops on 20 and 21 December 2000 over the Great Lakes region. Moisture transported into the area from the Gulf of Mexico is lifted by the fronts associated with the cyclone resulting in widespread snowfall. Courtesy of Dept. Atmospheric Sciences, University of Illinois at Urbana-Champaign
300mb Heights & Winds during an Alberta Clipper: The 300mb height and wind field of late December 2000 shows a strong trough over the central United States. This trough provided divergence aloft for a surface low that traveled eastward along the United States/Canadian border - an Alberta Clipper. Courtesy of Dept. Atmospheric and Oceanic Sciences, University of Wisconsin - Madison
850mb Heights & Temperatures during an Alberta Clipper: The 850mb temperatures show the cold air found north and west of an Alberta Clipper that traveled along the U.S./Canadian border in late December 2000. Bitter cold air is rapidly transported southward on the western side of the 850mb low into the Midwest as the cyclone moves eastward and out over the Atlantic Ocean. Courtesy of Dept. Atmospheric and Oceanic Sciences, University of Wisconsin - Madison