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5.3 Storms from the eastern sector 
Storms from the eastern sector (E - NE wind directions) pose a particular threat to the 
western basins of the Baltic Sea. 
a) With a stable high-pressure system over Scandinavia, often the ridge of an anticyclone 
from northern Russia, an easterly air flow passes across the southern basins. When a 
depression approaches from southeastern Europe or Poland, a steep pressure gradient 
forms along the southern or southeastern edge of the anticyclone. A SE - NE storm of 
rather long duration develops over the southern part of the Baltic Sea because the 
anticyclonic pressure pattern over northeastern Europe often has a quasi-stationary 
character. This wind pattern leads to a gradually rising sea level which reaches high 
values in the westernmost part of the southern basins, e.g. in the Bights of Mecklenburg 
and Wismar, which are open towards the northeast. An example of this anticyclonic 
pressure pattern over Scandinavia with an eastward extension was the meteorological 
situation on 12 January 1987, which resulted in a long-lasting E storm and rising sea 
levels, which reached 673 cm at the Wismar gauge. The wind setup was much less 
pronounced in the central parts of the coast and farther to the east. 
There are some easterly weather patterns, especially those in which the high-pressure 
zone over Scandinavia does not extend far to the east, in which only a rather small area 
of the southern Baltic Sea is affected by the wind field of the depression approaching 
from the southeast. A storm from N - NW directions developing as the depression 
approaches influences primarily the eastern and central parts of the coast, causing sea 
levels to rise only in these areas, e.g. on 29 November 1978, 18 January 1981 and 
6 September 1992. 
The above grouping of typical pressure patterns is not meant to be a classification of 
meteorological situations based on the similarity of their impact on sea levels along the 
southern Baltic coast. Such groups cannot be precisely defined because meteorological 
conditions in the area are continually changing, and it is impossible to find two identical 
pressure patterns even in an area as limited in extent as the Baltic Sea. Summarising 
the above, it can be said that, irrespective of the direction of the approaching depression 
and the prevailing pressure pattern, the response of sea levels in a particular section of 
the coast depends on its morphometric conditions and the resulting impact of the wind 
on the near-shore coastal waters. Any type of onshore wind may lead to a considerable 
rise of sea levels on the coast, provided it is strong enough and has a long fetch, both of 
which are factors extending the duration of the storm. The problem is to determine the 
threshold values of these factors. 
b) In some other stormy “easterly” situations, especially when the high-pressure zone over 
Scandinavia does not extend far eastward, the wind fields of depressions travelling 
northwards from the southeast or southwest may influence a rather limited area of the 
southern Baltic Sea. A NE - NW storm developing during the approach of a depression 
of this type usually does not extend farther west than the central coastal area, with sea 
levels in most cases rising only in these coastal sections. Storm events of this type 
occurred on 29 November 1978, 18 January 1981, and 6 September 1992.