Mobile radar projects in Colorado mountains

Water is a critical yet finite resource in the western U.S. and there is an ever-increasing need to improve quantitative precipitation estimates (QPE). The primary sources of QPE are weather radars and precipitation gauges. Yet due to the complex terrain of the Rocky Mountains, observations from these sensors have great uncertainty due to large gaps in radar coverage and sparse gauge networks. In order to better understand these uncertainties, mobile Doppler radar field projects were conducted in 2009 and 2010 in Colorado. Both projects included special rain gauge networks. The 2009 project was conducted in Gunnison County, Colorado using the NOAA/NSSL's NOAA/OU X-band Polarized research radar. Eleven portable recording tipping bucket rain gauges and four optical disdrometers were deployed along the eastern slopes of the West Elk mountains, an area of climatologically-preferred storm development. The polarization Shared Mobile Atmospheric Research and Teaching Radar deployed south of Durango, CO during August 2010 along with a network of thirteen gauges and two disdrometers in the San Juan Mountains in Colorado.

The objectives of these projects were to document the fine-scale spatial rainfall coverage and intensity in the complex terrain of CO, determine the potential for correction factors to WSR-88D data for improved operational QPE, and investigate the utility of dual-polarization technology. In addition, the 2010 Durango deployment included sending near-real time data to Weather Forecast Offices at Grand Junction and Albuquerque for evaluation in the Flash Flood Monitoring and Prediction – Advanced system.

This paper provides an overview of the projects and initial results. Implications for radar network designs to provide more complete coverage in complex terrain will be discussed.