Extended-Range Forecasts for the Southern Hemisphere with the ANMRC Spectral Model

Abstract

A series of twelve 4-day forecasts for the Southern Hemisphere was made, including both summer and winter cases using a hemispheric spectral model. The model had a resolution of wavenumber 31 in the horizontal and nine levels in the vertical. The model forecasts were verified in terms of various objective measures and a subjective evaluation of the synoptic charts. From this limited study it appears that the winter forecasts are significantly better than the summer forecasts. Given the present data network, analysis procedures and the parameterization of physical processes in the model used, the useful forecast period is about two days for summer and three days for winter.