Convective storms are of fundamental interest to scientists as well as important to the general public. Such storms produce severe weather that is economically disruptive and life-threatening as well as producing beneficial rainfall. Accurate short term predictions (up to 24 hours) of the location, timing, intensity and type of convective storm would be of substantial benefit to society. Using the Advanced Regional Prediction System numerical model developed at a NSF Science and Technology Center, Center for Analysis and Prediction of Storms, the Principal Investigator will attack various aspects of prediction of convective activity. By using broader parameter spaces as well as higher spatial resolution, more realistic methods for inserting pseudo-observational errors into the simulations during storm evolution, and a more accurate method for treating subgrid-scale motions, the Principal Investigator will evaluate the utility of various dynamical parameters in predicting storm behavior within a variety of environmental settings; examine linkages between helicity and energy dissipation; and attempt to understand how errors grow and propagate in convective storms so as to establish predictability limits as a function of storm type, environment and other parameters.