The predictability of seasonal maximum temperature in South Africa

Abstract

An analysis of the variability and predictability of seasonal mean maximum temperature over South Africa is conducted. Possible relationships between global scale sea-surface temperature fields and seasonal mean maximum temperature over South Africa are sought by means of a statistical technique, namely 'singular value decomposition'. Associations between sea-surface temperature and seasonal mean maximum temperature over South Africa are evident. In particular, associations between El Nino :Southern Oscillation related signals and seasonal mean maximum temperature over the eastern half of the country were found. Also, the long-term warming trend in the ocean temperatures has important influences on the temperature variability over South Africa. In this study canonical correlation analysis is used to construct a forecast scheme for the prediction of seasonal mean maximum temperature over South Africa at different lead times. Evolutionary patterns in the ocean temperature field are used as predictors from which categorical seasonal mean maximum temperatures for 77 stations in South Africa are predicted. Categorical seasonal mean maximum temperatures are predicted and evaluated for an independent test period to verify the skill and therefore usefulness of such predictions. © 1998 Royal Meteorological Society.