Using two- and three-dimensional thunderstorm models, Mr. Farley and Professor Orville have made considerable progress in recent years in refining our knowledge of the role of water and ice microphysics in the formation of microburst and the growth of hail. Under this award, the principal investigators will continue their work with emphasis on the three-dimensional models. Numerical simulations ranging from meso-beta and cloud scales to subcloud scale will be experimented with grid-nesting. The observations will be extracted from the North Dakota Thunderstorm Experiment scheduled for the summer of 1989, and from the CCOPE Project in Montana in 1981 and the COHMEX Project in Alabama in 1985.//
