"Fort Collins Flood"
28 July 1997

Case Summary

The Fort Collins, CO Flood was an unusual event for the location. The storm environment could best be described as "tropical" with an unusual amount of moisture through a deep layer of the atmosphere. Surface dewpoint temperatures approached 65°F with temperatures in the 80s. These tropical conditions lead to very efficient precipitation mechanisms. Backbuilding echoes increased the duration of the heavy rainfall period over the area. Enhanced duration and intensity of rainfall combined with urban runoff complexities and resulted in a very major hydrologic response. However, the intense rainfall rates and the urban environment were even more important than the duration, as is often the case with urban flash floods.

This event was one of the Significant Weather Events of 1997 and resulted in the loss of five lives and $190 millions in damage. For a more detailed description of the event, please view the Colorado Climate Center's Analysis.

Case Study 011