Understanding factors that control production of supercooled liquid water in mountainous terrain is not only an important fundamental research question, but such knowledge is needed to advance techniques of enhancing winter-time orographic precipitation. During the Austral winter of 1990, a joint experiment was held with scientists from Australia and the University of Nevada with most of the field costs covered by the Australian government. The research objectives were to measure mesoscale water budgets near mountainous terrain during the passage of extratropical cyclones and to understand how this budget is affected by mesoscale cloud structures. Under this renewal proposal, the Principal Investigator will continue his analysis of data collected during this experiment. His two research objectives are: to examine supercooled liquid water and precipitation development within moving mesoscale precipitation features and stationary orographic clouds associated with winter storms; and to estimate the precipitation efficiency of mesoscale features and orographic clouds to learn whether they contain excess supercooled liquid water which could be seeded for potential precipitation enhancement.
