Supercooled Liquid Water In Winter Storms: A Preliminary Climatology from Remote Sensing Observations


  • Kenneth Sassen Department of Meteorology, University of Utah


Drawing from a remote sensing data base obtained from winter storm research programs in Colorado and Utah, the occurrence of supercooled liquid water over mountain barriers is examined. Combined polarization lidar and dual-channel microwave radiometer data reveal that liquid water was nearly always presenting the storms studied. Moreover, the highest frequency of occurrence and liquid water amounts were most often associated with relatively warm cloud base temperatures and Ku-band radar reflectivity factors between 0 and -10 dBZ at the liquid cloud base position. A preliminary climatology of super cooled liquid water in southern Utah reveals a bimodal distribution of liquid cloud base heights, representing of convective clouds (-3.0 km MSL) and generally prefrontal stratiform clouds (~4.5 km MSL). Although the liquid water associated with the efficient natural generation of precipitation may not always be detected by any single probe, the conditions which could be expected to yield a favorable seeding response can be identified through joint remote sensing observations.






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