9 
1.4 Meteorological conditions accompanying high sea levels in 1951 -1999 
Storm surges on the southern Baltic Sea coast are most likely to occur after the passage of a 
low pressure centre with a system of atmospheric fronts. The most dangerous storms of the 
20th century raging along the entire southern coast usually accompanied a stormy 
depression tracking southeastward from the Norwegian Sea across Scandinavia and the 
Baltic Sea. 
Storm surges are induced by gale-force winds from northwesterly to northeasterly directions, 
which appear in the rear of such fronts. Storm surges of this type may last from a few hours 
to tens of hours. When such surges overlap with an already high sea level induced by large 
inflows from the North Sea, the resulting sea level may be very high, reaching extreme 
values in some cases. Sometimes the sea level rise begins simultaneously along the entire 
coastline, but more often the surges strike only part of the coastline or move along the coast. 
Heavy and long-lasting storms are usually accompanied by a considerable sea level rise 
along the entire coastline. 
2. LONG-TERM VARIATION OF STORM SURGE OCCURRENCE 
The long-term variation of storm surge occurrence and annual frequency distribution 
provides important information on this hydrological phenomenon. 
2.1 Gumbel probabilities 
Some principles of this statistical method were described by Stigge (1995b). The following 
table allows a comparison between the levels of flood protection (defence level - generalised 
mean sea level) and some high water levels of different probabilities of undercut P or 
intervals of recurrence T in years. 
Table 2.1. Some high water levels in m above MSL for Gumbel probabilities of undercut P 
and intervals of recurrence T in years for German coastal towns calculated in 2000 
Gauge/P 
0.80 
0.90 
0.95 
0.98 
0.99 
Defence 
level 
Name / T in years 
5 
10 
20 
50 
100 
Flensburg 
1.45 
1.63 
1.81 
2.04 
2.21 
3.50 
Schleimünde 
1.38 
1.54 
1.70 
1.89 
2.04 
3.70 
Eckernförde 
1.43 
1.63 
1.82 
2.07 
2.25 
3.60 
Kiel 
1.45 
1.65 
1.84 
2.08 
2.26 
3.40 
Neustadt 
1.38 
1.57 
1.75 
1.99 
2.16 
3.30 
Travemünde 
1.50 
1.70 
1.89 
2.14 
2.32 
3.70 
Wismar 
1.49 
1.68 
1.86 
2.09 
2.26 
3.20 
Warnemünde 
1.28 
1.44 
1.60 
1.80 
1.95 
2.85 
Stralsund 
1.17 
1.31 
1.45 
1.63 
1.77 
2.70 
Greifswald 
1.34 
1.50 
1.65 
1.85 
2.00 
3.00 
Swinoujscie 
1.16 
1.31 
1.46 
1.65 
1.80 
0.80 
Kotobrzeg 
1.13 
1.26 
1.39 
1.54 
1.66 
1.10 
The sequence of the gauges is from west to east. The highest levels occur in bights that are 
open to the northeast.