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Negative Surges in the Southern Baltic Sea 
5.14. January 1993 
Meteorological situation 
With an anticyclone over southern Europe, north 
ern Europe was under the influence of low pres 
sure. In the morning of 13 January, an active, 
newly formed depression from the Atlantic Ocean 
approached the British Isles from the southwest. 
The depression and associated fronts moved 
northeast, deepening fast, and reached the Kat 
tegat by night. Early on 14 January, the depres 
sion crossed southern Sweden and the Baltic 
Sea Proper and, slowing down, entered Estonia 
at 09 UTC. At 15 UTC on the same day, the 
depression was centred over St. Petersburg, 
from where it turned east, filling as it reached the 
area south of Lake Onega. On 13 January, strong 
westerly winds backing southwest prevailed over 
the southern part of the Baltic Sea. Early on 
14 January, as the low pressure centre and fronts 
crossed the Baltic Sea, the gale-force wind 
developed into a heavy storm which reached 
hurricane force over the southern Baltic Sea 
region between 02 and 06 UTC. Before leaving 
the Baltic Sea area in the morning of 14 January, 
the low pressure trough forced the storm to veer 
temporarily west to northwest (Fig. 5.14. a), 
causing the wind, still strong and gusty, to back 
and calm down very slowly. 
Hydrological response of sea level 
On the days preceding the surge, strong south 
westerly winds kept sea levels considerably 
below the mean values. The gauge at Wismar, for 
example, recorded levels below 420 cm for about 
6 hours on 13 January. In the following night, 
disturbances of wind direction and speed near 
the advancing atmospheric fronts first provoked 
a small decrease (between 00 and 03 UTC), then 
a rapid but short-lasting rise of water levels 
(between 02 and 06 UTC). The highest level of 
about 560 cm was recorded in Kotobrzeg, 
530 cm was reached about one hour earlier in 
Warnemünde, and about 535 cm was recorded 
at Swinoujscie at 05 UTC. 
This rise of water levels was followed by a much 
steeper drop: the water level in Swinoujscie 
dropped 130 cm in 4 hours, in Kotobrzeg about 
120 cm in 3 hours, and in Wismar 110 cm in 
6 hours. The decrease stopped abruptly when 
the storm veered slightly onshore. The minima at 
the individual stations were as follows: Kotobrzeg 
439 cm at 08 UTC, Swinoujscie 400 cm at 
09 UTC, Wismar 367 cm at 10 UTC, Sassnitz 
386 cm at 14 UTC, and 404 cm in Warnemünde. 
After having reached their minima, water levels 
rose again rather quickly though very unevenly 
due to the impact of highly variable air flow. 
Fig. 5.14. a Route of the low pressure centre from 09 UTC on 13 January to 00 UTC 15 January 1993, 
pressure pattern and wind field over the Baltic Sea at 06 UTC on 14 January 1993