The NOAA National Severe Storms Laboratory (NSSL) deployed a mobile radar near Durango, Colorado, during the month of August to collect data on thunderstorm rainfall and resulting flash flooding. The deployment was part of the collaborative “Southwest Colorado Radar Project” to better understand and forecast an annual event known as the “Southwest Monsoon.”
Historically, the Southwest Monsoon has triggered many flash floods across the mountains of Colorado killing more than 350 people since the late 1800’s.
Flash flooding is the leading cause of hazardous weather-related deaths.
Project sponsors include the Colorado Water Conservation Board, Colorado Division of Emergency Management, Southwestern Water Conservation Board, and the Southern Ute Indian Tribe.
NSSL shared real-time data from the Shared Mobile Atmospheric Research and Teaching Radar (SMART-R) with the National Weather Service (NWS) Weather Forecast Office in Grand Junction, Colorado, for comparisons with operational observations. The SMART-R is equipped with dual-polarization technology, which more accurately estimates precipitation amounts. The mobile radar was located on Bridge Timber Mountain, southwest of Durango, and at the Durango-La Plata County Airport.
Earlier this summer, the same SMART-R mobile radar was used in the Great Plains during the VORTEX2 tornado research project.
Over a dozen recording rain gauges were installed in the San Juan Mountains by the National Center for Atmospheric Research to help calibrate the radar data. Additional recording rain gauges were provided by counties in southwest Colorado, the Southern Ute Tribe, and the NWS. Ft. Lewis College and Durango-La Plata County airport are hosting additional meteorological sensors provided by the NSSL and the University of Colorado.
NSSL’s Q2 project, a suite of products that combine the most effective multi-sensor techniques to estimate precipitation, was a test bed platform for the merging of SMART-R data with data from surrounding WSR-88D radars.
NWS storm spotters, official climate observers, and CoCoRaHS (Colorado Collaborative Rain and Hail Study) climate observers provided additional reports of rainfall, hail, and other significant weather for the duration of this radar research project.
The project demonstrated the potential of a gap-filling radar in the Four Corners region, a region not optimally observed by surrounding NWS WSR-88D radars, leaving uncertainties in surface rainfall rates. The NWS will assess the usefulness of the data for improved detection of flash floods, and NSSL will use the data for advanced evaluation of dual-polarization rainfall algorithms.
A similar project was held in the upper Gunnison River Basin last summer.