Objective
To conduct a pilot program to evaluate the effectiveness of snowpack augmentation
in two regions of Wyoming.
Description
The Wyoming Water Development Commission, on behalf of the State of Wyoming, is overseeing the conduct of the Wyoming Weather Modification Pilot Program, a winter cloud seeding program to increase snowpack and runoff within Wyoming's Green River, Wind River, and Platte River basins. This program involves cloud seeding operations, to be implemented by Weather Modification, Incorporated (WMI) based in Fargo, North Dakota, and scientific evaluations, performed by the National Center for Atmospheric Research (NCAR) Research Applications Laboratory (RAL).
Cloud seeding technology will be used in the pilot program and evaluated as a long-term water management tool rather than as a tool to mitigate the effects of drought conditions. Cloud seeding is most effective under normal or near-normal weather conditions. However, the benefits during dry years cannot be ignored.
The Wyoming weather modification program consists of two project regions that will use cloud seeding in an attempt to increase precipitation (snowpack) over targeted mountainous areas by up to 10 - 20 % per year; amounts well within the range of natural variability between winter seasons and for individual storms. The two proposed pilot cloud seeding regions are located in two diverse and widely separated areas, the Medicine Bow/Sierra Madre Mountains and the Wind River Range of Wyoming.
Ground-based and airborne cloud seeding efforts using a silver iodide-based
seeding agent are planned for each pilot program region over a period of 4.5
months, from November 15th through March 31st, over five successive winter
seasons. The pilot program will continue for a period of five years because
natural variability is high and five years should allow the technology to
be demonstrated over a range of winter conditions. Intense storm systems that
are forecast to produce heavy snows would generally not be seeded, because
these storms have been shown to be naturally efficient in producing precipitation.
Under average conditions, seeding may be feasible six to ten times per month
in each evaluation target area. Seeding in each event may vary from an hour
to many hours, depending on the persistence of suitable clouds. Monitoring
and evaluation of specific evaluation target areas will continue throughout
the 5-year pilot program and will culminate in a final report. more
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Project Sponsor:
Wyoming
Water Development Commission (WWDC)
