Global prediction of cumulative rainfall statistics from the simple knowledge of the yearly rain amount

An upgraded version of a one-parameter model for the prediction of the 1-minute Cumulative Distribution Function of rain rate (P(R)) is presented and tested. The model retains the analytical formulation proposed by the ITU-R Rec. P.837-5, but two out of its three input parameters, the 6-hour rainy period probability, Pr6, and the convective-over-total precipitation ratio, beta, are replaced by their average values pertinent to the meteorologically homogeneous areas identified in the study. The third parameter, the yearly rain amount, Mt, is the only site specific input. Tests have shown the ability of this simple model to reproduce measured P(R)s with very good approximation.