On satellite images, a midlatitude cyclone is often identifiable by a comma-shaped cloud mass.

A single cyclone can influence the weather over a large area, (in this case from Texas into Minnesota). This particular storm (in the satellite image above) left more than six inches of snow from Nebraska into Minnesota, while heavy rains occurred from Missouri into Texas.

Here is a movie loop of color enhanced infrared images spanning 18 hours. The center of the cyclone was initially located over the southcentral portions of the United States. As the cyclone evolved over time, notice the counterclockwise rotation of clouds around the cyclone center.

air masses

Terms for using data resources. CD-ROM available. Credits and Acknowledgments for WW2010. Department of Atmospheric Sciences (DAS) at the University of Illinois at Urbana-Champaign.

Upper Air Features