Utah Division of Water Resources meteorologist Jonathan Jennings briefed the Weber River Watershed Council on Nov. 26 about the state’s cloud‑seeding operations, recent expansions to drone platforms and a coordinated evaluation and environmental study to quantify benefits and monitor impacts.

Jennings framed weather modification as a scientifically studied tool best described as "rain enhancement," not a replacement for other water‑management strategies. He said Utah operates remotely controlled ground generators, aircraft programs and is now piloting drone‑based seeding in the Bear River Basin under FAA waivers. "This is the first time anything like this has ever happened," he said of the large drone program that will release silver iodide directly into cloud volumes and that Utah is funding at roughly $3,000,000 per year while Idaho contributes about $1,000,000.

On evaluation, Jennings acknowledged that assessing cloud seeding’s signal above natural variability is challenging because monitoring has historically relied on point observations. He described a multi‑partner field campaign (SNOWSCAPE) to deploy dozens of precipitation sensors, radiometers and radars to better capture cloud and precipitation processes, and to ingest that data into dispersion and hydrologic models for a stronger evaluation.

The state will conduct an environmental baseline and follow‑up sampling to measure trace silver in snow and water; samples will be analyzed at specialized labs (University of Wisconsin was cited as capable of parts‑per‑trillion analysis). Jennings said silver iodide in seeding agents is chemically bound and that modeled concentrations are well below EPA drinking-water standards and toxicity thresholds reported in the literature, but the environmental study is intended to provide local baseline measurements and monitoring.

Jennings cited prior state and program evaluations indicating a roughly 6–12% measured increase in snowpack using target/control methods and broader program estimates of 10–15% gains in some contexts; he stressed variability across terrain and the importance of albedo and delayed runoff for water‑supply benefits.

Members asked about costs and data ownership; Jennings said long‑term program costs translate to an estimated $10–$20 per acre‑foot of water production (state estimate) and that improved instrumentation and ensemble modeling are intended to provide policymakers better ROI calculations.