Mammatus Clouds (IMAGE) Colorado State University Caption Mammatus clouds, associated with strong convection, grace a sunset over Fort Collins, Colo., home of the NOAA Cooperative Institute for Research in the Atmosphere at Colorado State University. Credit Steve Miller/CIRA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.