Numerical Simulations of Low-CAPE Flows over a Mountain Ridge

In a recent study, the authors performed numerical simulations of conditionally unstable flows past a mesoscalemountain ridge in order to investigate the statistically stationary features of the solution precipitationcharacteristics for intermediate-to-high values of convective available potential energy (CAPE). That studyproposed a functional dependence of the rain rate on three parameters, related respectively to the triggeringand the orographic forcing of convection and to the ratio of the advective to convective time scales. The presentstudy extends that analysis to cover larger regions of the parameter space, including experiments correspondingto a wider range of CAPE. It is found here that the low-CAPE, moderate-wind experiments do not fit thefunctional dependence for rain rate amount and location proposed in the authors' previous study. The analysisof the present solutions suggests that two additional nondimensional parameters should be taken into account.