Supercooled liquid water and precipitation enhancement opportunities in Australian winter mountain storm clouds

A study is made of supercooled liquid water in winter storm clouds over the Great Dividing Range of Victoria. The implications for precipitation enhancement by cloud seeding are considered. Several cloud and precipitation variables are treated. One is the supercooled liquid water flux in clouds passing over a target area for precipitation enhancement near Baw Baw Plateau east of Melbourne. Another variable is the precipitation flux over the target area. The ratio of these two fluxes is the seedability. The precipitation efficiency is the inverse ratio. One finding of the study is that winter storm clouds often produce precipitation with an efficiency that is only 0.2-0.3. At the same time the seedability varies from three to five during the storm studied. This high seedability suggests that cloud seeding as currently practiced could be improved, with a range of appropriate instrumentation and procedures, and a higher precipitation increase achieved.