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<br />2. Analyses of Past Seasons, and 1985 C-band Doppler Radar Studies of Kine- <br />1I8tics <br /> <br />A combination of instruments (C-band and K-band Doppler radars, <br />radiometer, lidar, etc.) is beginning to provide a more comprehensive <br />picture of the evolution and workings of ~,inter orographic clouds. <br /> <br />With these instruments and subsequent analysis, there have been <br />several findings: <br /> <br />A. Airflow toward the Tushar Mountains ,raries in an understandable, if <br />not predictable, way during a storm nssociated with a cold front <br />passage. The airflow affects liquid formation and precipitation <br />development and seeding material dellvery. <br /> <br />B. The motion of constant colume balloons and the trajectories of <br />tracer materials are being examined to help establish the potential <br />for ground-based seeding. <br /> <br />C. Analysis of NCAR C-band Doppler data allows quantitative estimates <br />of convergence, updrafts, and rate of production of depositable <br />water substance in near upwind regions of the Tushar Mountains. <br /> <br />D. Radar estimates of depositable water substance are related to radio- <br />metric supercooled liquid water and precipitation rate. <br /> <br />E. Terrain can have a strong effect on the spot distribution of super- <br />cooled liquid water in cases of low-level flow toward the terrain. <br />The azimuths to various concentrations of radiometric liquid water <br />will depend on the chosen location of the radiometer and the direc- <br />tions to terrain features. <br /> <br />F. Radiometric measurements of liquid water often show rapid changes <br />between azimuth scans. This suggests the need for technical im- <br />provements to the radiometer to shorten its effective time constant. <br /> <br />G. The University of Utah lidar shows great detail in the evolution at <br />least the lower strata of orographic clouds, and its data are <br />complementary in important ways to those of the NOAA/WPL co-located <br />radiometer and Ka-band radar and surface microphysical observations. <br /> <br />H. There is some evidence of relatively more liquid water in shallow <br />orographic clouds, but the frequency of this may vary with season <br />and storm characteristics. <br /> <br />3. Analyses of Past Seasons and 1985 Tracer/Delivery Studies <br /> <br />A. Brief Summary of 1983 Analysis Resull~ <br />, <br /> <br />NAWC analyzed the 1983 5-cm weather radar data to derive half-hour <br />precipitation e(~ho types over the Tushar barrier. Six different radar <br />echo types were identified. One of the most frequent types was one in <br />which there was no 5-cm radar return but there was precipitation reported <br /> <br />39 <br />