Even though dozens of countries practice cloud seeding, there has been very little rigorous academic study into whether it actually works. That’s changing. Scientists at University of Colorado Boulder have been running some promising trials in Idaho:
For the cases presented, precipitation gauges measured increases between 0.05 and 0.3 mm as precipitation generated by cloud seeding passed over the instruments. The total amount of water generated by cloud seeding ranged from 1.2 × 105 m3 (100 ac ft) for 20 min of cloud seeding, 2.4 × 105 m3 (196 ac ft) for 86 min of seeding to 3.4 x 105 m3 (275 ac ft) for 24 min of cloud seeding.
Although this study focuses only on three cases, the results are a fundamental step toward understanding cloud seeding efficacy that, for over half a century, has been an unanswered question for water managers wishing to utilize the technology for water resource management.
This from Katja Friedrich and colleagues, published in PNAS last month. Link here and some nice coverage of the work here in Science Daily. Maybe cloud seeding can offset any climate impacts on Western snowpack formation. The initiative is called SNOWIE (Seeded and Natural Orographic Wintertime Clouds – the Idaho Experiment).