Pseudo-Precipitation: A Continuous Precipitation Variable

The discontinuous and highly nonlinear nature of precipitation makes its statistical manipulation, like the reduction of bias in quantitative precipitation forecasts (QPF) or probabilistic QPF (PQPF) problematic. To ease the statistical post-processing of precipitation, a new continuous variable, pseudo-precipitation (PP) is introduced. Pseudo-precipitation is equal to precipitation when precipitation is nonzero and is proportional to the vertically integrated water vapor deficit (with a negative sign) otherwise. The concept of PP and its practical application is illustrated with analyzed and forecast data samples.