Right at the beginning, a DWD expert quite correctly observed: ”The climate change is beyond dispute, opinions are only divided on how much of it was caused by mankind.‟ After this topic was ticked off, the essentials were put forward. According to the DWD, floodings in Northern Italy, Slovenia and Croatia are due to a very rare weather phenomenon which was even augmented by the influence of the sun and the moon.
This means, a long-established anticyclone is dwelling over parts of Northern Africa and, at the same time, there is a widespread low pressure area over Scandinavia and Central Europe. And, as a matter of principle, winds always blow the direction from an anticyclone to a depression, the Adriatic was under the influence of strong southers pushing the waters towards its northern coast. Nevertheless, this alone was not sufficient. In addition, there was the influence of the tides as well as the full moon, with the force of the sun still enhancing the moon’s gravitation. And, in the case an approaching low pressure system would be heading towards the northern Adriatic region where it is pouring buckets of rain, i.e., up to 500 litres per square metre, the water continues to rise as the strong winds prevent part of the waters from draining off.
Mind you: 500 litres per square metre in a closed vessel would mean a water column 50 centimetres high. This situation is aggravated by the fact that intense precipitations on the southern flanks of the Alps partly came down as rain, partly as snow, finding their way back to the Adriatic Sea in the form of surface water.
Such an occurrence is actually very rare, the last time such a weather event happened about 50 years ago, as is reported from Venice. For the coming weeks, the DWD has given a slight all-clear: the winds and the effects of the tides on the water levels are decreasing, so the additional water masses from the northern Adriatic region can flow off and the situation will gradually ease. The consequences of the climate change, according to the DWD, always comprises a much greater time period than this time-limited flood event.
This assessment of the situation by sea Hamburg weather experts seems to be exactly right, as the SeaHelp support point in Lignano reports decreasing water levels, too. And only now, the extent of the damage as a whole is becoming more and more evident.