Mesoscale convective systems in weakly forced large-scale environments. Part III: numerical simulations and implications for operational forecasting

Abstract

Results suggest that mesoscale models may be capable of producing useful simulations of convective events associated with weak, large-scale forcing, including quantitative precipitation forecasts with the correct magnitude and approximate location of heavy rainfall, if the important mesoscale circulations are incorporated into the model initial condition and a sufficiently realistic trigger function is used. Results indicate that the effects of boundary layer forcing must be included in the trigger function in order to initiate convection at the proper time and location. The locations of heavy rainfall are shifted by greater than 100km, or disappear altogether, if particular mesoscale features are not included subjectively in the initial condition. -from Authors