Presentation description

One of nature's deadliest weapons is flash flooding. Southeastern Utah is particularly vulnerable to flash flooding events arising from summer thunderstorms that deposit intense rain in very short amounts of time. These bursts of heavy rain, combined with soils that absorb little moisture, contribute to rapid runoff in local slot canyons, rivers, and creeks. This region does not have many permanent residents, but attracts millions of visitors annually to the region's many national parks and recreational areas. On 21 June, 2024, widespread flash flooding took place across this entire region, resulting in widespread damage, as well as two fatalities. The atmospheric conditions are described that led up to this event. Composite reflectivity images are obtained from NEXRAD Level 2 radar data from the KICX (Cedar City, UT) and KGJX (Grand Junction, CO) radars. Streamflow data comes from the US Geological Survey (USGS) to analyze discharges in the San Juan River at Bluff, as well as Mill Creek in Moab. The Iowa Environmental Mesonet provided data to visualize precipitation deviations from average. Precipitation accumulation data was sourced both from the USGS, as well as MesoWest. Finally, lightning density data was derived from the National Lightning Detection Network (NLDN).