Could we help bring rain to fight fires by using cloud-seeding?

OGDEN -- Don Griffith is wondering if there isn't some way he could put out the massive fires near Los Angeles, something thousands of firefighters and millions of dollars haven't been able to do.

Griffith can be allowed such fantasy. Rain puts out fires, and his job is to make rain. Utah and water districts around the state pay his company, North American Weather Consultants, nearly half a million dollars a year and, he says, get back thousands of acre-feet of rain.

How much? It's hard to be precise, but Tage Flint, executive director of the Weber Basin Water Conservancy District, said the $24,000 he pays Griffith boosts his district's take about 5 percent.

Five percent is a lot when you're talking 600,000 acre-feet in the Ogden, Weber and Bear river drainages, he said. As an investment, it works out to about $2.50 an acre-foot, which is very cheap water.

"That's why we keep doing it," Flint said.

Not everyone thinks rainmaking is a good investment, at least not as government funds are drying up.

Nevada, the driest state in the nation, recently stopped funding rainmaking, saving $550,000 at a cost of an estimated 65,000 acre-feet of water. The funds were part of $2 million in cuts to the Desert Research Institute in Reno.

Utah is the second-driest state in the nation, and Griffith feels the pain of the rainmakers in Nevada.

"Some of the real pioneers in cloud seeding worked in Australia," he said, then moved to Nevada "and were very instrumental in developing a very well-respected capability in weather modification that's continuing to the present time."

His company contracts with individual water districts and the state. Over the years, he said, he has been able to boost precipitation statewide by 5 to 7 percent.

There is a popular image of cloud seeding being done by airplane: The plane flies over, seeds fall out of it, and it rains.

Reality is much different.

While it can be done from planes, almost all cloud seeding in Utah is done with silver iodide sprayed into the air from ground generators.

Griffith had 150 generators scattered around the mountains from Logan to St. George last year. He puts them out in October and they work through the winter.

Generators produce microscopic silver iodide crystals that float up into a cloud. In that cloud, if conditions are right, water vapor forms either liquid water or ice crystals around the silver iodide.

When the drops or snowflakes get big enough, they fall.

Nevada's decision to stop rainmaking won't really add much to Utah's take, he said. He said only a small percentage, perhaps 15 percent, of the moisture in a cloud falls as rain. Rainmaking adds 5 percent of that 15 percent, so the extra amount Nevada is leaving in clouds that float over Utah isn't all that great.

The issue of robbing Peter to pay Paul does come up, though. Flint said he's glad most of his rainmaking is done on storms that drop snow and rain on Utah's Uinta Mountains.

"We don't have to contend with a lot of other water users immediately east of us, so it works out pretty well," he said.

Griffith has wondered if cloud seeding could help put out forest fires because of an interesting phenomenon in which large fires actually create clouds. Griffith said people saw that happen in the massive Yellowstone Park fires in 1988.

Fires vaporize all the moisture in the plants and trees they're burning up. That vapor rises until it hits cold air and condenses, sometimes forming huge clouds.

"You'd actually see clouds forming over the fire because of the air streams pushing moisture up," he said. They are sometimes referred to a "pyrocumulus" clouds.

"If those clouds were to get their tops up above freezing level, yeah, I think you could potentially seed them to potentially induce precipitation to form."

He proposed the idea to the Forest Service more than a year ago but, "I never got much response."