Cloud Seeding: Enhancing Winter Snowpack to Bolster Utah’s Water Supply Lily Lambert1, Kendall Becker1,2, Binod Pokharel3,4, Scott Hotaling1,2 1
Utah State University (USU) Climate Adaptation Intern Program 2 USU Department of Watershed Sciences 3 Utah Climate Center, USU 4 USU Department of Plants, Soils, and Climate
For decades, Utah has been experiencing a declining snowpack paired with a shorter period of snow accumulation (Hotaling & Becker, 2024). These changes are negatively impacting Utah because the state relies heavily on snowpack for its water supply, agriculture, and recreation–– especially for winter sports such as skiing and snowmobiling. Warmer winter temperatures driven by climate change will continue to decrease Utah’s snowpack (Hotaling & Becker, 2024). Although large-scale mitigation efforts are needed to reduce greenhouse gases and slow warming, local adaptation tools can reduce impacts in the near term. One of these tools is cloud seeding—a safe, common form of weather modification that augments natural precipitation under suitable conditions by increasing the precipitation capacity of existing clouds. In Utah, cloud seeding is only performed in the winter, and current estimates suggest that where cloud seeding is used, it enhances the local snowpack by 3%–13% (Flanagan, 2024c, 2024d; Osborne & Yorty, 2024a, 2024b; Yorty, 2024a, 2024b).
Highlights
In this fact sheet, we describe what cloud seeding is, where it is currently used in Utah, and the safety measures and management practices that ensure its responsible use. 1
•
Cloud seeding is a safe form of weather modification that has been used in Utah since the 1950s to increase snowfall in targeted areas.
•
Comparisons of seeded and unseeded areas in Utah indicate that cloud seeding increases precipitation by 3%–13%.
•
Cloud seeding can increase precipitation when existing clouds are within an ideal temperature range and contain supercooled liquid water.
•
Warmer winter temperatures in Utah’s mountains could decrease the percentage of clouds suitable for seeding from 60% to 40%.