WSPC03871 - Laserfiche WebLink

Home Browse Search

002541 (7) To perform preliminary analyses of processed data to obtain the characteristics and distribution of precipitation and other meteorological parameters over the San Juan Project area. The winter season 1974-75 was the final data collection season for the WSSI effort. The final report was dated March 31, 1976. It discussed the analyses of the comprehensive data sets collected during the 6-year investigation, with emphasis on describing the precipitation season, the type and frequency of storm days, the precipitation sequence in storms, the distribution of precipitation with elevation, the areal distribution of cumulative precipitation over the San Juan Mountains, the relationship of precipitation between adjacent gages, and the characteristics of daily and hourly precipitation amounts. Activated ice nucleus concentrations and precipitating ice crystal data were examined for evidence of cloud seeding. Finally, the precipitation data collected during the summer 1971 to 1974 seasons were analyzed to determine the contribution of summer precipitation to runoff. The final report evaluated the instrumentation selected for the CRBPP, the network design, and the equipment developed for the project. Sixteen recommendations were developed for future oro- graphic projects based on the experience gained from the CRBPP. CONTRACTOR: University of Wyoming, Laramie, Wyoming CONTRACT NO. 14-06-0-6801 PRINCIPAL INVESTIGATOR: Donald L. Veal PERIOD: July 1,1974, to August 31,1976 FUNDING: FY75 - $125,000 FY76 - $ 55,000 The University of Wyoming conducted a detailed study of the micro- physical and dynamical processes of the storms over the San Juan Mountains during the winter of 1974-75. Investigators studied both seeded and nonseeded storms to evaluate seeding potential and to search for seeding effects. Case studies of 12 storms followed the storm systems through the stable, neutral, unstable, and dissipation stages. Microphysical observations yielded several surprising results. Supercooled water regions were less extensive than antici- pated, and ice crystal concentrations were unexpectedly high. Analysis of the seeding potential of the San Juan storms concluded that the stable storm stage at the beginning has low seeding poten- tial; however, a physical basis for seeding the San Juan storms, particularly during unstable storm stages when much supercooled water is transported to high altitude and lost from the precipitation mechanism, is apparent. This water could be converted to additional precipitation if properly seeded. 11-6