Evaluation and Optimization of Orographic Cloud Seeding to Enhance Precipitation in California
The Regents of the University of California, on behalf of the Davis Campus
Recipient
Davis, CA
Recipient Location
3rd
Senate District
4th
Assembly District
Completed
Project Status
Project Result
After kicking off in August 2025, the research team embarked on several significant project milestones. The team has begun characterizing opportunities for cloud seeding in California using the 40-year, 4-km WRF simulation over the continental US (CONUS404). Model set-up for the weather research and forecasting cloud seeding model (WRF- WxMod) and the weather research and forecasting hydrological model (WRF-Hydro) configurations is in progress. Two new instruments have been deployed at the Central Sierra Snow Lab (CSSL) to assess the impact of background aerosol and cloud condensation nuclei concentrations, which will be used in concert with existing observations to thoroughly explore the optimal conditions for orographic cloud seeding in California. A workflow to perform a retrospective analysis of radar data has been established in an effort to unequivocally identify cloud-seeding signatures for the first time in California. The project team also hosted a Preliminary Stakeholder Workshop at UC Davis in November 2025, which included representatives from PG&E and SCE.
The Issue
Cloud seeding for precipitation enhancement has been performed for decades, but only recently has it been conclusively demonstrated in the intermountain Western US that the process can be effective. As California strives to meet SB 100 goals and build climate resilience, cloud seeding could be an important strategy for bolstering zero-carbon electricity generation resources. This project will make a step towards demonstrating cloud seeding’s efficacy in California’s Sierra Nevada mountains and illuminating optimal conditions and seeding strategies for both precipitation enhancement and ultimately hydropower augmentation.
Project Innovation
This project will evaluate and improve understanding of how to optimize orographic cloud seeding in California in order to enhance precipitation and runoff into hydroelectric reservoirs. The project will examine the lifecycle of enhanced snowfall from seeding, using a multidisciplinary approach. This approach includes assessing the impact of background aerosol and cloud condensation nuclei concentrations, coupling of models that make it possible to simulate the impacts of seeding from precipitation through to melt and runoff, and the recipient will partner closely with energy stakeholders to determine how best the research results can be leveraged to meet the state's statutory energy goals.
Project Goals
Project Benefits
This project advances the scientific basis for optimization of orographic cloud seeding in California in ways that enhance precipitation and runoff into hydroelectric reservoirs. The project examines the lifecycle of enhanced snowfall from seeding using a multidisciplinary approach. This approach includes assessing the impact of background aerosol and cloud condensation nuclei concentrations, coupling of models that make it possible to simulate the impacts of seeding from precipitation through to melt and runoff, and the recipient partners closely with energy stakeholders to determine how best the research results can be leveraged to meet the state's statutory energy goals.
Key Project Members
Adele Igel
Subrecipients
The Regents of the University of California, on behalf of the Berkeley Campus
Stockholm Environment Institute U.S., Inc.
National Science Foundation National Center for Atmospheric Research
Match Partners
The Regents of the University of California, on behalf of the Davis Campus
