Wednesday, September 23, 2015   |   Case Studies

Hildale, Utah Flooding Event – Sept. 14, 2015

On September 14, 2015, a severe flooding event occurred around 6 p.m. CDT in the Hildale, Utah area. Prior to the storms that caused the flooding, the region had already received several rounds of rain/storms with areas west/north of Hildale having already received .50-1.0” of rain over the previous 24 hours.

At 5 p.m. CDT, strong storms were moving back into the region from the south/southwest.

utah_flood_5pm_ref

At 5:14 p.m. CDT, the storm quickly approached the Hildale area. Notice the Baron Storm Track associated with the storm, which would have alerted residents of the approaching strong storm.

utah_flood_515pm_ref

Baron Dual-Pol Rain Rate shows the approaching storm is producing substantial rainfall rates of 3-4” per hour. It should be noted that these intense rainfall amounts would only last roughly 10 minutes at any one location.

utah_flood_518pm_rain_rate

At 5:23 p.m. CDT, the core of the thunderstorm was passing directly over Hildale, as well as the canyons immediately to the north. At this time, the storm was displaying an intense 70.5 dBZ of reflectivity.

utah_flood_523pm_ref

By 5:39 p.m. CDT, the strong storm had already moved north of the town of Hildale; however, additional storms producing heavy rains railed behind the original storm producing additional rainfall amounts for the area.

utah_flood_539pm_ref

3-hour Dual-pol Rain Accumulations at 6 p.m. CDT showed the thunderstorms that affected the town of Hildale and areas immediately north produced .90-1.20” of rain over the previous 3 hours.

utah_flood_6pm_dp_accums

The Baron Hail Swath product indicated that there was likely some hail mixed in with the intense rainfall as well.

utah_flood_hail_swath

The following three images are of NavWeather’s current weather product. They indicate moderate to heavy rain in the vicinity of Hildale for more than 30 consecutive minutes, leading up to the time of the tragic flooding event.

utah_flood_520pm_currentwx

utah_flood_535pm_currentwx

utah_flood_550pm_currentwx

The following two images are of Baron Road Conditions showing that for some time leading up to the tragic flood event, roads were possibly flooded due to the heavy rain in the vicinity of Hildale.

utahflood_530pm_roads

utah_flood_550pm_roads