From The Pueblo Chieftain (Matt Hildner):
Southern Colorado Farms, which has used the program for 15 years on its ground northwest of town, has reapplied for a permit with the Colorado Water Conservation Board.
The farm uses the cannons to pelt storm clouds with sound waves. In a cloud in which hailstorms have yet to form, the practice prevents them from forming. But if the clouds coming over the farm are already latent with hailstones, the cannons aren’t able to break them down, said Amy Kunugi, the farm’s general manager. “Sometimes it works and sometimes it doesn’t,” she told 14 people who attended the permit hearing.
The cannons are a way to protect the farm given that crop insurance for lettuce and spinach are not available, she said. Since their last permit hearing five years ago, the farm has recorded its use of the cannons and set up a system of rain and hail gauges on the property During that span, the farm deployed the cannons an average of 11 times per year, with a high of 22 times in 2007 and a low of once last year.
Opponents and skeptics of the hail cannon plan raised concerns that there wasn’t enough monitoring downwind of the farm to know the full impact of the use of cannons.
More coverage here. (Scroll down.)