Observed changes in extreme temperatures over Spain during 1957-2002, using Weather Types

The aim of this paper is to identify and analyze the daily variability of observed changes in the extreme temperatures in relation to the atmospheric circulation. In order to carry this out, a joint probabilistic analysis of Weather Types (WTs) and the corresponding surface observations has been performed, comparing daily surface observations of extreme temperatures, in two different periods of time (1957-1979 and 1980-2002) over mainland Spain and the Balearic Islands. The results show that there were significant changes in the extreme temperatures between the two periods of study; moreover, these changes were heterogeneous in space, time and WT. Finally, we have noticed that these observed alterations were more related to changes in the extreme temperatures of the corresponding WTs than to changes in the occurrence probability of the WTs.