Extratropical Cyclones Forming East of the Rocky Mountains

Online 10.3: An Upper-Level Cyclone Crosses the Rockies Water Vapor Satellite Imagery: This animation of water vapor satellite imagery shows where high concentrations of water vapor are present in the middle and lower atmosphere (bright white regions). Darker areas identify drier regions. Note the tropical origins of the moisture feeding into the center United States. This moisture (water vapor) will condense into droplets to form clouds and eventually precipitation associated with severe thunderstorms that forms just south of the low pressure center. Counterclockwise rotation around the low pressure center can be discerned starting in the Arizona / New Mexico region and migrating into the Texas panhandle. During this time sequence, heavy snow fell in the central and eastern half of Colorado.