Meteorological factors contributing to negative surges 
29 
SEa - South-East Anticyclonic 
N 
1200 
■ 1000 
• 800 
■ 600 
■ 400 
200 
0 
■200 
■ —400 
-€00 
Fig. 4.4. c Atmospheric situation SEa (South-East Anticyclonic) from the group of meridional situations. 
Weather situations like this have caused long-lasting negative surges £440 cm on the southern Baltic Sea 
coasts (average surface level pressure anomaly chart, after G. Cawley) 
The first group of meridional situations usually 
induce negative surges of short duration, similar 
to the zonal and mixed types of atmospheric sit 
uations discussed above. During the period stud 
ied, 11.3 % of negative surge events were attrib 
utable to this group of atmospheric situations, 
with HB being the most important single situa 
tion. 
Only 5.1 % of all negative surge events were 
attributable to the second meridional group. They 
included events of above-average duration. 
Among southerly and southeasterly atmospheric 
situations, which are closely related and account 
for 4.8 % of all negative surges observed, the 
southeasterly anticyclonic type (SEa) prevailed 
(Fig. 4.4. c). It should be noted that no negative 
surge event of very long duration occurred in the 
central part of the southern Baltic Sea coast in 
the 56 years analysed in this monograph.