The sensitivity of simulated convective morphologies to cloud microphysical scheme parameters

Over the past twenty years, a number of weaknesses in understanding inherent in the design of bulk microphysical parameterizations have been identified. The uncertainties in particle parameter specifications can significantly affect the processes that govern warm season convective system morphology and especially rainfall. While modifying the uncertain parameters in microphysical parameterizations can alter precipitation patterns, it is yet unclear if the processes involved in the morphology of different types of mesoscale convective systems [linear (trailing, leading and parallel stratiform) and non-linear] have different sensitivities to microphysics.

The present study will use the Weather Research and Forecasting (WRF) Advanced Research WRF (ARW) model at fine grid spacing (4 km or less) to investigate the sensitivity of different types of mesoscale convective systems to changes in fall velocities. The experiment will provide an understanding of the important processes involved in the morphology of different types of convective systems. The effects of this experiment on precipitation forecast accuracy will also be examined.