Rainfall nowcasting by at site stochastic model P.R.A.I.S.E

Abstract

The paper introduces a stochastic model to forecast rainfall heights at site: the P.R.A.I.S.E. model (Prediction of Rainfall Amount Inside Storm Events). PRAISE is based on the assumption that the rainfall height H i+1 accumulated on an interval Δt between the instants i Δt and (i+1) Δt is correlated with a variable Zi(v) representing antecedent precipitation. The mathematical background is given by a joined probability density fHi+1,Z i(v) (hi+1,zi(v)) in which the variables have a mixed nature, that is a finite probability in correspondence to the null value and infinitesimal probabilities in correspondence to the positive values. As study area, the Calabria region, in Southern Italy, was selected, to test performances of the PRAISE model.