Simulation of an Air Mass Thunderstorm Using the Two-Scale Model

Abstract

The two-scale model (Raymond, 1979) is used to simulate a well-documented Colorado thunderstorm. Good agreement is found with the early and middle stages of the storm life cycle. Intense vertical mixing in the early stages is shown to have a crucial effect on both cloud dynamics and microphysics. In particular, precipitation particles formed at high levels in the storm are rapidly mixed down to low levels against the mean updraft even when sedimentation is suppressed. The termination of this mixing not only enables the simulated storm to develop explosively, but also sets the stage for its eventual demise.