Most severe negative surges on the southern Baltic Sea coast 
39 
Fig. 5.7. a Pressure pattern and wind field over the Baltic Sea on 9 March 1969, 00 UTC 
5.7. March 1969 
Meteorological situation 
In the early hours of 8 March, a weak ridge of 
high pressure moved east across the Baltic Sea, 
with moderate westerly to southwesterly winds 
blowing on the southern coasts. In the afternoon, 
an active low pressure centre with an associated 
frontal system moved from the Norwegian Sea 
toward southern Sweden, where it arrived early 
on 9 March. Here, it slowed down slightly and 
changed direction toward the Baltic Sea Proper, 
continuing in easterly direction. In the afternoon 
of 8 March, the wind increased gradually and 
reached 7-9 Bft on the southern coasts. Shortly 
after midnight on 9 March, the squall line of a 
cold occlusion passed across the two eastern 
most water level gauges, while the western 
gauges remained in the area of the less gusty 
southwesterly storm, which was increasing in 
severity. 
Around noon on 9 March, a secondary cold front 
moved first across the water level gauges in the 
eastern part of the southern Baltic coast, then 
those in the western part. The storm, which now 
reached 9-10 Bft and 11 Bft in gusts, veered 
west and northwest, slowly decreasing in the 
evening. 
Hydrological response of sea level 
In the morning of 8 March, sea levels oscillated 
between 480 cm and 460 cm, falling gradually 
under the influence of freshening offshore wind. 
Levels had dropped to 450-430 cm by night, and 
shortly after midnight on 9 March all gauges 
except the Kotobrzeg station recorded levels just 
under 420 cm. 
At the same time, shallow minima of 430 cm and 
412 cm were recorded at Kotobrzeg and 
Swinoujscie, respectively. Levels at the western 
gauges continued to sink slowly, and the minima 
were reached around noon: 408 cm in Sassnitz 
at about 11 UTC, 392 cm in Wismar at 12 UTC, 
and 398 cm in Warnemünde at 13 UTC. 
Around this time, the disturbed water level curves 
at Kotobrzeg and Swinoujscie showed secondary 
minima. Levels rose again under the impact of 
the northwesterly storm and reached 520-480 cm 
in the late hours of 9 March.