Idaho Research Shows Cloud Seeding Works as Western States Seek Cure for Severe Drought


The drought in the western United States is so severe that it’s now getting frequent headlines in the east, where rainfall has been plentiful.

The latest comes from the Washington Post, which zeroes in on Idaho Power’s efforts to prove the worth of its two-decade-long cloud-seeding program for southern Idaho and eastern Oregon.

The private utility estimates its cloud-seeding operation results in about “600,000 acre-feet of additional water in the Payette, Boise and Wood River basins as well as over 400,000 acre-feet of additional water each year in the upper Snake River basin.”

Much of Idaho and Oregon are facing dire drought conditions.

You’ve probably heard about cloud seeding now and again over the years. Scientists discovered way back in the 1940s that injecting silver iodide into certain winter storm clouds appeared to prompt more rainfall, and various states and countries have been doing this for years to increase mountain snowpack.

But it’s always been hard to pin down whether this environmental manipulation really was making rain fall.

Now the Post reports that “the first unambiguous evidence that cloud seeding can increase snowpack levels” has led to a “small renaissance” in the practice.

That evidence, coming from Idaho Power’s work and the National Center for Atmospheric Research (NCAR), arrived last year.

The study, “Quantifying Snowfall From Orographic Cloud Seeding,” received little attention when it was published, no doubt because it landed in March 2020, just as the coronavirus pandemic was rolling over the country. But one NCAR scientist called the results “a revelation.”

“This study,” the authors write, “uses the approach of combining radar technology and precipitation gauge measurements to quantify the spatial and temporal evolution of snowfall generated from glaciogenic cloud seeding of winter mountain cloud systems and its spatial and temporal evolution.”

Got that?

The upshot, the researchers insist, is a more rigorous scientific approach to determining whether cloud seeding actually works. And the answer is … yes, cloud seeding does work. Though not by a huge amount.

The increase in precipitation that cloud seeding offers ranges from 3% to 5%.

But at this point, said Julie Gondzar, who heads Wyoming’s cloud-seeding effort, “every little bit helps.”