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FINAL OPERATIONAL SEEDING SUMMARY REPORT for the SAN JUAN WEATHER MODIFICATION PROGRAM WESTERN WEATHER CONSULTANTS, INC. submitted an application for a permit to augment natural winter precipitation in the southwestern portion of the San Juan Mountains. to the Colorado Department of Natural Resources. on August 19, 1983. The seeding areas requested for the operational 1983-1984 winter snowpack augmentation program were the Animas, La Plata, Mancos and Dolores River Drainages. This application was discussed at a public meeting held on October 7, 1983, before David H. Getches, Executive Director and Barbara Welles, Weather Modification Program Director, Colorado Department of Natural Resources, at 1:30 p.m., Room 110, 1313 Sherman Street, Denver, Colorado. Western Weather Consultants, Inc. was represented by Lawrence M. Hjermstad. President. WESTERN WEATHER CONSULTANTS, INC. received a Weather Modification Permit Renewal for the drainages in the San Juan Mountains listed above, granted effective November 15, 1983 and in force until March 31, 1984. One of the stipulations of the permit was that no generator should be operated under conditions when the plume might be. expected to reach Silverton, Colorado; other stipulations related to seeded area boundaries, generator sites, the selection of weather systems. suitable for seeding and program suspension criteria. The program was operationally ready by November 15, 1983, with six ground- based cloud nuclei generators in place to seed the southwestern San Juan target area. All of the generators were manually operated and utilized silver iodide as the nucleating agent. The first seeding for the 1983-1984 winter season was initiated on Nov- ember 24th; this was the only seeding event during November. During December there were four seeding events with the last one ending on December 20th. There were no seeding operations conducted during the last third of December because of heavy natural snowfall in the San Juan Mountains. The Snow Survey Unit of the Soil Conservation Service (SCS) estimated that at the end of Dec- ember, basin-wide snowpack statistics for the Dolores and Animas drainages were 184 percent of average. This exceeded program suspension criteria; there- fore, all seeding operations were suspended for January. . During January, precipitation over most of southwestern Colorado averaged less than half of the long-term average for the month. Estimates made by the SCS Snow Survey Unit at the end of January indicated that basin~wide, the snow- pack for the Dolores and Animas drainages were 144 percent of average. This was slightly above the 140 percent suspension criteria set for the month of February. The decision was subsequently made to place the San Juan program in a stand-by mode for February and keep operations suspended.