"Mesoscale Cloud Systems and Their Effects on Larger Scales of Motion" Many of the factors that are critical for understanding and predicting weather that is disruptive to human activity occur on what meteorologists term the mesoscale. Mesoscale phenomena are not well sampled by the operational weather network; therefore, progress is made through episodic field experiments specifically designed to study mesoscale processes. The principal investigator will study a broad range of mesoscale problems using data collected during NSF sponsored research programs. Numerical models of the convective and stratiform regions of mesoscale convective systems will be applied to and tested on analyzed data sets collected during the Global Atmospheric Research Program's Atlantic Tropical Experiment (GATE) and the Oklahoma-Kansas Preliminary Regional Experiment for STORM-Central (PRE-STORM: STORM stands for Stormscale Operational and Research Meteorology). Multiple Doppler derived wind fields of mesoscale convective systems observed during the PRE-STORM and of Hurricane Norbert will be constructed and used for quantitative diagnostic studies of the budgets of water, heat, momentum and wind circulation. The vertical distribution of momentum, wind circulation and large-scale environmental heating associated with these storm systems will be estimated from this data. Such calculations are of great importance to mesoscale research since the effect of these mesoscale systems on the larger scale circulation is an unknown energy transfer mechanism which is of great importance in controlling the weather.