Mammatus At Sunset
September 08, 2004
The remarkable photo above was taken at sunset early last month from near Pueblo, Colorado and shows an impressive mammatus cloud formation. These pendulous clouds were observed just after a huge thunderstorm, producing baseball sized hail and heavy rain, ravaged parts of Pueblo. While mammatus clouds aren't always precursors of severe weather, their appearance is certainly menacing. They typically form as a result of cold downdrafts within mature thunderstorm cells.
Today is the 4th anniversary of the Earth Science Picture of the Day.