Numerical Weather Prediction Studies from the FGGE Southern Hemisphere Data Base

Abstract The quality of numerical weather prediction available for the Southern Hemisphere from the FGGE data base has been examined. The Australian Numerical Meteorology Research Centre (ANMRC) spectral prediction model has been initialized with analyses produced with the operational system of the Australian Bureau of Meteorology, and experimentally from the ANMRC assimilation scheme. The predictions to 48 hours from the assimilation-based analyses were at least comparable with operational levels of performance, even though the latter require substantial manual interaction. The impact upon predictions of TIROS-N retrievals and drifting buoy surface pressures was assessed by omitting these observing systems in turn from the assimilations. Both systems impact positively upon predictions. The effect of the buoys is greatest at sea level. The effect of the retrievals is evident both at sea level and aloft.