Debris Flow — Garfield, Colorado

2023-08-26 · near Allen, Garfield, Colorado

Event narrative

The Colorado Department of Transportation reported 4 separate mudslides occurred along portions of I-70 within the Grizzly Creek Fire burn scar as a result of heavy rain from thunderstorms. The slides took place east of Hanging Lake Tunnel and 30 cars were trapped in between the flows. The largest slide took place near the westbound exit ramp of Bear Ranch and was roughly 50 feet long and covered one lane. The radar estimated precipitation totals of 0.65 to 0.85 inches north of the interstate with 1.80 inches measured at the East Fork Dead Horse automated gauge. The road remained closed until early on the morning of the 27th.

Wider weather episode

Even as high pressure began to build into the region, plenty of deep moisture remained entrenched across western Colorado. This led to another round of scattered showers and thunderstorms. Daytime heating and marginal instability fueled some stronger storms, particularly over the higher terrain. One such storm was nearly stationary over the east side of the Grizzly Creek Fire burn scar for an extended period of time, which resulted in some debris flows over I-70. Additionally, heavy rain from storms resulted in debris flows in portions of Ouray County.

View location on OpenStreetMap → (39.5940, -107.1820)

Source: NOAA Storm Events Database, event_id 1113811. Narrative written by the NWS forecast office that issued the report.