Development and Testing of Single‐Parameter Precipitation Distributions

A general procedure was developed for calibrating multiparameter probability distributions of daily precipitation to single‐parameter distributions. The approach uses monthly precipitation summaries and data from U.S. Weather Bureau Technical Paper 57 (Miller and Frederick, 1966). The three‐parameter beta‐ P model of daily precipitation amount was calibrated for 33 sites east of the Rocky Mountains. The resulting single‐parameter Weibull distribution and two other single‐parameter precipitation distributions were compared with respect to their fit to Paper 57 summaries and historical daily precipitation records. The Weibull model was shown to yield significant improvement over the other models in reproducing precipitation probability distributions.