Cloud Seeding
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When you think of drought, you might picture cornstalks wilting under a hot summer sun, or clouds of dust rising on a roadside. You probably don't think of snowless mountain slopes and downcast skiers in the winter.

I'm Dave Thurlow and this is the Weather Notebook.

Drought can have just as big an impact in winter as it does in summer, especially in the western U.S. Skiing is big business there, and the snowpack is the main source of water for many areas. That's why cloud seeding takes place across the west each winter. Just like the rainmakers of summer, these cloud seeders sprinkle silver iodide into existing clouds.

The idea is to kick-start the natural process by which ice crystals form and grow inside a cloud, leading to snow. The people who do cloud seeding say they can raise snowfall as much as 10 to 15 percent. These figures are hard to prove, because you can never tell what would have happened if you hadn't seeded a particular cloud. Still, the state of Utah has been seeding in the winter since the 1970s, and a number of western ski areas are sold on the idea.

Durango Mountain, in Colorado, just jumped back on the bandwagon after stopping its program in the 1980s. The last two winters were so dry that the resort decided to give seeding another try. The local newspaper noted that cloud seeding won't make a bad winter great, but it could make a marginal seasonal better--and sometimes that's all a tourist industry really needs.

Thanks today to writer Bob Henson. And to the National Science Foundation and Suburu, the beauty of all-wheel-drive. The Weather Notebook is a production of the Mount Washington Observatory. Visit us on-line at www.weathernotebook.org.