Extratropical Cyclones Forming East of the Rocky Mountains

Edition 1 - Example of Rocky Mountain Cyclone Visible Satellite Imagery of the April 2001 Cyclone - Visible satellite imagery from 11 and 12 April 2001 shows the comma cloud associated with a Rocky Mountain cyclone that moved into the Great Lakes area from the Central Plains. The leading front south of the cyclone is visible as a distinct line of clouds next to clear skies. Rotation of the low is evident in the widespread cloud structure as it moved into the Great Lakes. Nighttime darkness limits the tracking of the storm in visible imagery.