Recent developments in long‐range forecasting in the Meteorological Office

Six years ago at the end of November we issued the first monthly forecast to the British public. At that time the forecasts were based on an Analogue Selection procedure and a so-called Physical Discussion. In principle these two inter-related approaches still form the basis of the present operational method, but considerable changes have taken place and these are reflected in a modest improvement in the accuracy of the monthly forecasts. This overall improvement arises from three main sources. In the first place, we have steadily extended and improved our store of readily available, processed data. Many people have of course been responsible for the essential data-processing side of our work, which is still continuing, but I must mention J. M. Craddock and M. H. Freeman for laying good foundations in the early days. In the second place, we have carried out numerous synoptic and empirical studies. All of these have given useful background information and some understanding of the nature of large-scale circulation and weather anomalies. Many of our investigations have been aimed at providing statistically based aids for the prediction of UK weather. We have increased the scope and range of our studies which are not confined to the monthly time scale. In particular a good deal of work has been done on the seasonal time-scale, and in the past year or two we have carried out experimental forecasts, originally for winter and summer but now for every season. In the third place we have gained a lot of experience of the particular problems as a result of both research and operational forecasting. I would like to touch upon a few points in elaboration of these remarks.