COMPARISON OF 3-PARAMETER PROBABILITY-DISTRIBUTIONS FOR REPRESENTING ANNUAL EXTREME AND PARTIAL DURATION PRECIPITATION SERIES

Performance of 8 three-parameter probability distributions for represe nting annual extreme and partial duration precipitation data at statio ns in the northeastern and southeastern United States is investigated. Particular attention is paid to fidelity on the right tail, through u se of a bootstrap procedure simulating extrapolation on the right tail beyond the data. It is found that the beta-kappa distribution best de scribes the extreme right tail of annual extreme series, and the beta- P distribution is best for the partial duration data. The conventional ly employed two-parameter Gumbel distribution is found to substantiall y underestimate probabilities associated with the larger precipitation amounts for both annual extreme and partial duration data. Fitting th e distributions using left-censored data did not result in improved fi ts to the right tail.