A new wind zone map of Germany

The revised version of the wind zone map of Germany is based on a refined extreme value analysis for three physical phenomena which are leading to high gust wind speeds: the typical storms induced by strong frontal depressions, thunderstorms and additional gust fronts especially in weaker frontal depressions which are induced by down-drafts of cold air and/or by rain and which are not fully covered by the usual flow field models of frontal depressions. Individual ensembles for each of these storm phenomena have been sampled for a large number of stations. Furthermore, it has been tried to increase the statistical stability of the estimated representative values by summarizing stations with a similar wind climate. The fitting of the theoretical extreme value distribution is performed for only the right tail of the observed traces of non-exceedence probabilities. The proposed new map presents five wind zones with characteristic values from 22.5 to 32.5 m/s. The zoning follows mainly the boundaries of the administrative districts. Compared to the preceding wind zone map, the new map specifies for many sites smaller wind loads. Additionally, directional effects have been analysed, however, the results are too inhomogeneous to be included in the code.