Debris Flow in Garfield County, Colorado

Major flash flooding and debris flows occurred throughout Glenwood Canyon from the Grizzly Creek Fire burn scar as a result of significant rainfall from showers and thunderstorms. Multiple mudslides were reported by the Colorado Department of Transportation (CDOT). Numerous vehicles were trapped between slides for several hours. Rainfall rates in excess of 4 inches/hour were estimated with storms. Remote gauges recorded between 1 and 2 inches in less than an hour along the south and east sides of the burn scar. CDOT reported damage to the structure of Interstate 70 which remained closed for over two weeks due to cleanup operations and surveys.

Substantial monsoon moisture remained over the area as high pressure drifted east over the Plains. Additionally, strong instability was in place as a midlevel shortwave trough moved overhead. As a result, widespread showers and thunderstorms developed across the area with many storms producing heavy rain. This led to multiple debris flows across portions of west-central Colorado including over the Grizzly Creek Fire burn scar. Additionally, a severe thunderstorm produced large hail in Garfield County.