Probabilistic hydrometeorological forecasts: Toward a new era in operational forecasting

Under the auspices of the Cooperative Program for Operational Meteorology, Education and Training, pilot research has been conducted from 1991 to 1996 on operational methods for producing Probabilistic Quantitative Precipitation Forecasts (PQPFs) and Probabilistic River Stage Forecasts (PRSFs). The first integrated forecasts were produced using operational data and models of the National Weather Service on 19 October 1996. The PQPF was for a 24-h period and the PRSFs were for lead times of 1, 2, and 3 days. This article discusses these pilot forecasts, their interpretation, and their advantages to forecasters and end users with regard to communicating uncertainties and making decisions.