Glaciogenic Cloud Seeding Potential in Southwest Montana

The Montana Department of Natural Resources and Conservation (DNRC) has interest in assessing the potential for glaciogenic cloud seeding to augment snowpack and subsequent streamflow in southwestern Montana. Based on outcomes from a climatology study of clouds and precipitation characteristics over the region, the Big Hole Basin was selected for initial focus of a feasibility and design study. The climatology study included using SNOTEL precipitation observations as well as the CONUS404 dataset (a 4-km, 40+ year high-resolution, hydroclimate reanalysis) under the current climate and future climate scenarios; key outcomes from the study provided insight for where and when to optimally employ ground-based and/or airborne cloud seeding and a preliminary program design was developed. To evaluate the potential impacts of the preliminary program design, WRF-WxModⓇ, a state-of-the-art numerical model developed at NSF NCAR that can simulate the physics of cloud seeding with silver iodide, was run for multiple case studies. A variety of ground-based and airborne program design scenarios were simulated in order to evaluate potential increases in snowpack from glaciogenic cloud seeding over the Big Hole Basin target area. This presentation will highlight key findings, including a refined program design based on results from the modeling component of this study.