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. . . . aircraft flights were suspended due to -severe turbulence and icing. The system therefore allows measurements to be taken in a wider variety of storm situations, including those where cloud liquid is primarily confined to regions below the minimum altitude allowed for aircraft terrain avoidance. Several case studies were used to document the cross-barrier tendencies of SL W. Some cases revealed marked temporal variability in the spatial distribution of liquid while others documented relatively steady- state conditions over periods of several hours. Numerous individual cross-barrier profiles and the average seasonal profile indicated that the maximum liquid depth occurred considerably upwind of the center of the plateau. Comparisons of mobile and stationary radiometer data also proved very useful in verifying this feature both temporally and spatially. Local topographic features, such as a minor valley and ridge on top of the plateau, influenced cloud liquid development, but the general trend of liquid depth to decrease from west to east was most likely due to removal by growing precipitation particles, the lack of vertical motion over the plateau top and downward motion upwind of the eastern edge of the plateau due to a westward tilted mountain wave. The removal by precipitation was supported by data that showed _ seasonal precipitation maxima downwind of liquid maxima. The depletion of water across the top of the plateau has. cloud seeding implications, in that a radiometer positioned on the windward slope or near the west edge of the top will likely overestimate the supercooled water that is available for precipitation augmentation by cloud seeding. The relatively infrequent number of observations across the plateau top warrants further observations to verify the general decrease in cloud liquid. With knowledge of cloud base height and temperature, the mobile radiometer measurements were found to be useful in developing estimated vertical profiles of cloud liquid. The adiabatic assumption used will not characterize the typical precipitating storm situation, but the average estimated cloud thicknesses agreed relatively well with the "mean" conditions during one aircraft flight and with earlier lidar- radiometer studies on another mountain barrier in Utah. The cloud seeding implications in both regions were similar; supercooled liquid was often available, but the temperatures in the lower cloud layer were generally warm compared to the activation temperature of the silver iodide compound used in Utah. The profiles also demonstrated the need for cloud seeding aerosols to be delivered to liquid zones as far upwind as possible to increase the probability of particle trajectories terminating on the plateau. _ This study represents one application of the mobile radiometer platfonn. Additional work is planned for the use of the data in verification of three-dimensional cloud model results for the Wasatch Plateau region and more detailed water budget studies for this mountain barrier, using a two-radiometer method. 8.16. Super, A. B., 1995a: Case studies of microphysical responses to valley-released operational AgI seeding of the Wasatch Plateau, Utah. J. Weather Modification, 27, 57-83. ABSTRACT . . An experimental field program was conducted on the Wasatch Plateau of central Utah in early 1991. Objectives included monitoring of the transport and dispersion of valley-released silver iodide and associated microphysical effects within the seeded clouds. Silver iodide ice nuclei were monitored by acoustical ice nucleus counters in a truck, an aircraft and at a Plateau-top observatory. An aircraft- mounted ice particle imaging probe was used to search for ice particle concentration differences between the seeded cloud and crosswind, nonseeded cloud. Other instruments monitored wind, cloud liquid water content, temperature and other parameters of interest. . . 61 l