NWS Salt Lake City Support for the Brian Head Fire Burn Scar Debris Flows (83)

Darren Van Cleave, NOAA/NWS/WFO Salt Lake City, Salt Lake City, UT

Glen Merrill, NOAA/NWS/WFO Salt Lake City

Brian Mcinerney, NOAA/NWS/WFO Salt Lake City

Al Martinelli, NOAA/NWS/WFO Salt Lake City

 

Abstract:

In June of 2017, the Brian Head fire was ignited in southern Utah near the small resort town of Brianhead. This fire quickly grew to become one of the largest timber fires in Utah history, with supportive fuels in place due to rampant dead timber from beetle-kill in previous years. The fire burned very hot in many locations, leaving charred soils ripe for quick discharge of rainfall runoff. Combined with steep terrain on the northwestern flank of the burn scar this lead to frequent flash floods and debris flows during July and August 2017, which caused frequent washouts of the main highway connecting the town of Brianhead, Utah to the nearby interstate. Additionally, these events caused extensive damage downstream to homes and public utilities in the town of Parowan, Utah.

The National Weather Service (NWS) Weather Forecast Office (WFO) in Salt Lake City provided extensive support to public safety and transportation officials with an interest in flash flooding and debris flows from the Brian Head fire burn scar. Within a month of the fire, WFO Salt Lake dispatched staff to place a remote weather station on a particularly-sensitive drainage. This station was configured to send alerts to WFO Salt Lake forecasters when key rainfall thresholds were met, and also to transportation officials with the Utah Department of Transportation. In 2018, further research from the United States Geological Survey (USGS) Landslide Hazards Program lead to more robust understanding of flash-flood-prone areas and specific rainfall sensitivities. WFO Salt Lake was able to incorporate modeling from USGS into local forecast software to better predict potential flash flood threat areas. This poster will detail the operational support WFO Salt Lake has provided, as well as cutting-edge research-to-operations efforts in conjunction with the USGS.