CONVECTIVE RAINFALL REGIONS OF PUERTO-RICO

Geographical regions of covariability in hourly precipitation over the island of Puerto Rico are exposed using factor analysis. It is argued that the data are consistent with a common factor model when an orthg onal rotation is applied to the factor loading matrix. The results sug gest that Puerto Rico can be divided into six regions, with each regio n having a similar covariance structure of summer season convective ra infall. The six regions can be grouped into a western area and an east ern area based on contrasting diurnal rainfall signatures. The study i s the first step in developing improved forecast guidance for precipit ation over the island. It is believed to be one of the first studies a ttempting geographical regionalization of precipitation on the convect ive scale.