Storm surges from extra-tropical cyclones

The possible influence of climate change on the tracks of the extra-tropical cyclones as well as storm surges is studied. Two different data bases have been used: one for the Great Lakes of North America and the other for the German Bight in the North Sea of Europe. For the Great Lakes region, significant east-west and north-south shifts in the tracks of ETC'S with decadal periodicities have been observed. However, there was no trend in the amplitudes of storm surges. The most important result for the Great Lakes is that, depending upon its position relative to the constantly shifting storm tracks, a given location could either experience a major storm surge or could miss out completely. The storm surges in the German Bight in general, and at Cuxhaven in particular, appear to show a slightly increasing trend in the latter part of the 20th century. However, the most significant result for the German Bight is that the number of storm tides (i.e., multiple peaks in a given storm surge event) definitely has shown an increase in the second half of the 20th century. This increase is interpreted as due to the influence of meso-scale weather systems embedded in the synoptic scale ETCs.