45 
Fig. 6.10.2. Sea level changes during the storm surge of December 1989 
As the surge was preceded by comparatively low water levels, it reached a considerable 
amplitude ranging from 1.8 m in the western part to 1.3 m in the central parts of the coast, 
with water levels in these areas rising by an average 12.6 and 6,3 cm/h, respectively. The 
alarm levels were exceeded at all gauges, and sea levels remained high for periods ranging 
from 7 hours in Sassnitz to 12 hours in Kotobrzeg. Referred to the reference level indicator of 
513 cm on 6 December, this surge lasted from 21 hours in Wismar to 33 hours in Kotobrzeg. 
The final phase of the surge decay was accelerated by additional forcing due to stormy 
offshore winds in the western coastal zone of the Baltic Sea in the late hours of 7 December 
and on the next morning. This caused sea levels to drop to rather low values (467 cm in 
Wismar and 475 cm in Warnemunde on 8 December at 08 UTC) only a short time after the 
maximum had been reached. As soon as the wind abated and the water was no longer 
forced away from the coasts, sea levels in the western section of the coast returned to rather 
high values (560 cm in the western part, 550 cm in the central part of the coast) in the 
afternoon and late hours of 8 December. 
6.11 January 1992 
Meteorological situation 
On 16 January, Scandinavia and the Baltic Sea were influenced by a wide and deep 
depression (985 hPa) which moved slowly northwards from its position over Lake Ladoga. A 
secondary depression forming over the Norwegian Sea began to deepen and travelled 
southeastwards in the early hours of 16 January. It moved across central Scandinavia, the 
Aland Isles, Estonia and Latvia in one day, and its centre, with an atmospheric pressure as 
low as 982 hPa, reached the western parts of Bielorussia on 17 January, 06 UTC.