Model prediction performance over the Southern Ocean and coastal region around East Antarctica

The Antarctic Meteorological Centre (AMC) at Casey Station, Antarctica (66.28°S 110.52°E), provides an analysis and prognostic service, over the summer months, to the Australian National Antarctic Research Expeditions (ANARE) and other organisations traversing the Southern Ocean around East Antarctica. Included in the service is a daily mean sea-level pressure (MSLP) prognosis, valid for 1200 UTC on the same day. The two numerical models available to the AMC, upon which the manual products are based, include the Australian Global Assimilation and Prediction system (GASP) (Seaman et al. 1995 and Bourke et al. 1995) and output from the European Centre for Medium-range Weather Forecasts (ECMWF). A comparison of skill scores for the ECMWF MSLP prognosis and the AMC manual prognosis over the summers of 1993/94 and 1994/95 showed that the forecasters were able to produce minor improvements in forecast skill over the numerical guidance. However, a preliminary study of numerical model skill for the period June 1994 to early January 1996, although highlighting a steady improvement in model performance, found there to be relatively poor model skill in the East Antarctic region, with a major source of error appearing to stem from the base analyses used by the models.