Debris Flow in Garfield County, Colorado

Public reported water, rocks, mud, and other debris over Colorado State Highway 139 between mile markers 29 and 30, or about 5 miles south-southeast of Douglas Pass. The area around and south of Douglas Pass is very steep and prone to rock, mud, and debris flows under heavy, intense rainfall such as what fell on the afternoon of August 25th.

A strong southwesterly jet aloft was in place of eastern Utah and western Colorado, not only advecting rich monsoonal moisture into the area, but also providing enhanced lift a some decent wind shear. All this to say the environment was perfect for stronger, and more organized convection to form during the afternoon hours of August 25th. With the above normal moisture and indications of potential training thunderstorms, as well as the fact of the unusually supportive environment itself, the local Grand Junction office issued a Flash Flood Watch for portions of the area, in addition to a moderate risk of excessive rainfall from the Weather Prediction Center and a slight risk of severe weather from the Storm Prediction Center, prompting a Severe Thunderstorm Watch.