Performance of the ECMWF and the BoM Ensemble Prediction Systems in the Southern Hemisphere

Abstract The performance of two ensemble prediction systems, that of the European Centre for Medium-Range Weather Forecasts (EC-EPS) and that of the Australian Bureau of Meteorology (BM-EPS) are compared over the Southern Hemisphere annulus (20°–60°S) and over the Australian region. Ten-day ensemble forecasts for 152 daily cases (from 2 April to 31 August 2001) of 500-hPa geopotential height are examined. A comprehensive set of verification measures documents the different spread and skill characteristics of the BM-EPS and EC-EPS. Overall, EC-EPS deterministic (i.e., unperturbed control) products and the probabilistic ensemble-based products are more skillful than the corresponding BM-EPS products. The utility of the BM-EPS for the Australian region is indicated.