Climatological Assessment of Winter Orographic Cloud Seeding Opportunities in Wyoming

Over the past 14 years, the state of Wyoming has invested in several research studies to investigate the potential for cloud seeding to enhance wintertime snowfall in key mountain ranges in the state. These studies included an assessment of climatological data in order to determine if the atmospheric conditions are conducive to seeding with silver iodide (AgI). The mountain ranges included in this study are the Wyoming Range, the Wind River Range, the Bighorn Mountains, and the Medicine Bow and Sierra Madre Ranges. Snow gauge data from SNOTEL sites were analyzed to characterize the precipitation in these regions. Radiometer and sounding data (as available) were also analyzed to examine the presence of liquid water and the thermodynamic characteristics of the atmosphere in these regions. However, the latter observations are quite limited (in both spatial and temporal coverage), and yet are crucial for understanding the amenability of clouds to cloud seeding. Therefore, the observational analysis was augmented with an 8-year, high-resolution (4-km grid spacing) model simulation that provided modeled values of temperature, winds, liquid water, and precipitation over these regions. This study integrates the observational and model-based analysis results from these climatological studies over each region to provide a comprehensive view of the potential for cloud seeding in these mountain ranges in Wyoming.