Wyoming cloud seeding study enters its 4th year
by Wyoming Water Development Office
January 9, 2009
(Cheyenne) - A study aimed at determining whether or not cloud seeding technology can increase Wyoming’s snowpack entered its fourth season this winter.
The Wyoming Weather Modification 5-Year Pilot Program got off to a good start in December with multiple seeding events conducted in the Medicine Bow, Sierra Madre and Wind River Ranges.
The five-year pilot program, which was approved and funded by the 2005 Wyoming Legislature, is aimed at assessing the feasibility of cloud seeding technology to increase snowpack.
The Wyoming water modification program is being monitored carefully by scientists around the world. In its June 2008 edition, the international weekly science journal "Nature" called the program "the most promising (weather modification) experiment in America" and praised it as "the type of targeted and rigorous study that needs to be done in weather modification."
The current operational season is building on a successful 2007-2008 campaign that included 26 seeding events in the Medicine Bow/Sierra Madre Ranges and 26 seeding events in the Wind River Range. This season’s operations will run through April 15, 2009.
The Wyoming Water Development Office oversees management of the program. The project was specifically designed to assess cloud seeding as a long-term water management strategy in water short basins. Key to the Wyoming project is a strong independent physical evaluation of the program’s results.
The cloud seeding is targeted at very specific, defined areas. Conditions are monitored to determine when cloud seeding in these areas should be most productive.
"While the cloud seeding process is highly sophisticated, the more difficult aspect of the program is to verify whether the cloud seeding is providing real benefits in terms of snow pack," said Director Mike Purcell.
During the course of the study, Wyoming Water Development Office officials have fielded several inquiries from interested citizens with regard to closures of Interstate 80, potential flooding and additional snow removal at individual homes.
"The program targets specific mountain peaks in each of the study areas," Purcell said. "The anticipated maximum benefit is an increase of 10 to 15 percent to the snowpack in these study areas." He said the program’s criteria, developed by a technical advisory team, include safeguards that require the suspension of operations when warranted by weather conditions.
Weather modification, or cloud seeding, has been deemed a strategy for increasing stream flows in the Colorado River Basin by the Seven Basin States. Lower Basin entities in Nevada, Arizona, and California have initiated a program to cost-share with the Upper Basin states of Colorado, Utah and Wyoming for cloud seeding.
No ownership is implied by this participation and any additional precipitation and subsequent stream flow is treated as a natural event, and in the case of Wyoming, is subject to Wyoming water law. Over the past two years, the Lower Basin Entities have contributed significantly to the Wyoming program, with additional funding already approved for this year’s operations.
The Wyoming Weather Modification 5-Year Pilot Program has also afforded a unique opportunity to faculty and students at the University of Wyoming to study additional aspects of the cloud seeding program to include microphysical changes in cloud properties and the hydrological impacts due to seeding. These additional studies have been funded through the UW/USGS Water Research Program.