Census of Valley and Mountain Profiling Radar Characteristics during Winter Storms along Utah's Wasatch Front

Orographic precipitation in the western United States contributes to winter storms that affect transportation and public safety and build a snowpack that is critical for regional water resources. Due to fine-scale variations in topography and precipitation processes, orographic precipitation presents a major challenge for forecasting and understanding weather in mountainous regions. One region where orographic precipitation plays a significant role is in Little Cottonwood Canyon, which ascends into the central Wasatch Range southeast of Salt Lake City. During the cool season (October–April), the town of Alta at the top of Little Cottonwood Canyon averages 1200 cm of snow and 1050 mm of liquid precipitation equivalent, the latter four times greater than observed at the Salt Lake City International Airport only 37 km to the northwest. For the 2022/23 cool season, we installed and operated Micro Rain Radars (MRRs) and disdrometers at Alta and a low-elevation site (Highland High School) in the Salt Lake Valley to examine and compare lowland and upland profiling radar and hydrometeor characteristics during Wasatch Front winter storms. We will present comparisons of MRR reflectivity, doppler velocity, and spectrum width analyses, as well as disdrometer measurements, to illustrate key differences in storm structure and precipitation characteristics between the two sites due to valley dry layers, melting layers, mountain turbulence, and orographic convection.