The late-winter/early-spring storm activity in the western US has shifted north since the late 1970s. This graphic shows how the peak winter storm tracks have shifted poleward since 1978. The blue line shows the storm track for February, March and April of 1978. The red line shows the track for the same months during the year 1997.
This image may be used only to accompany a story about the research described in this release. Credit must be given to: Stephanie McAfee, the University of Arizona, 2008.