Observed trends in the daily intensity of United Kingdom precipitation

The intensity distribution of daily precipitation amounts in the UK has cha nged over the period 1961-1995, becoming on average more intense in winter and less intense in summer. This result is based on an analysis of 110 UK s tation records. In winter, and in terms of their relative contributions to total winter precipitation, there has been a decline in light and medium ev ents and an increase in the heaviest events. This change is fairly uniform across the whole country and is apparent even when longer records (with red uced spatial coverage/detail) are analysed back to 1931 or 1908. The revers e is found in summer: over 1961-1995 there has been a decline in the propor tion of the seasonal total being provided by the heaviest events. In the lo nger term context, however, the summer changes appear to be a return to ear lier levels after a period in the 1960s when heavy summer rainfall made a g reater than normal contribution. More complex changes have occurred in the intensity distribution of spring and autumn precipitation, with opposite ch anges in different regions of the UK. Copyright (VC) 2000 Royal Meteorologi cal Society.