Thunderstorm Wind in Grand County, Utah

A severe thunderstorm moved through portions of Grand County on the evening of the 21st, producing severe winds in addition to other hazards. The strongest winds likely occurred south of the KCNY ASOS at Canyonlands Field, as the core of the storm moved through Moab, about 10 miles to the south. The peak recorded gust was 58 mph at KCNY ASOS at 5:37 PM MDT. No reports of damage due to winds alone were received.

Very deep tropical moisture associated with the remnants of Tropical Storm Alberto combined with monsoonal moisture was forced through eastern Utah and western Colorado due to a large high pressure ridge over the Central U.S. and a deep low pressure trough over the Great Basin. This deep moisture combined with strong instability and shear to produce widespread severe weather across eastern Utah and western Colorado with thunderstorms producing severe wind gusts, large hail and heavy rain which resulted in flash flooding and debris flows. One particular storm even produced a landspout tornado in southeast Utah. Frequent lightning also resulted in lightning damage in Montrose, Colorado.