PREDICTING RAINFALL STATISTICS IN ENGLAND AND WALES USING ATMOSPHERICCIRCULATION VARIABLES

Regression models are developed to predict point rainfall statistics, with potential application to downscaling general circulation model (G CM) output for future climates. The models can be used to predict the mean daily rainfall amount and the proportion of dry days for each cal endar month at any site in England and Wales, and use the following ex planatory variables: (i) geographical (altitude, geographic coordinate s, and distance from nearest coast); and (ii) atmospheric circulation variables (mean values of air-flow indices derived from mean sea-level pressure grids). Values predicted by the models, for 10-km grid squar es covering the whole of England and Wales, are in reasonable agreemen t with the 1961-1990 climatology of Barrow et al. (1993). The potentia l use of the models in hydrological climate change impact studies is d iscussed. (C) 1998 Royal Meteorological Society.