Debris Flow in Grand County, Utah

A severe thunderstorm moved over the Moab area on the afternoon of the 27th, putting down very heavy rain and high rain rates. This caused flooding and debris flows across the area, including near Arches National Park. Flooding and debris flows outside the park on Highway 191 led to the closure of the road. Additionally, there were reports and photos of flooding and rockfalls/debris flows within the park on the scenic drive. These flows made the only entrance/exit road from the park impassable for a period of time.

Deep subtropical moisture increased across eastern Utah and western Colorado and combined with forcing from a strong low pressure trough digging across the Intermountain West to result in widespread severe thunderstorms. These storms produced severe wind gusts, large hail and heavy rain that resulted in flash flooding and debris flows.