Genoa – What is happening in our region? It is the classic “block situation”, as it is defined by us insiders. The Atlantic perturbation, the first real autumnal one, does not evolve, it does not pass to the east. Very hot sirocco winds coming from North Africa are loaded with humidity along the Tyrrhenian Sea and collide right on our region with the north wind coming out of the Apennine valleys. The CD point of convergence of these winds, unfortunately we are seeing it, it is the area of Savona and the far west of Genoa. In Roussillon, our station has already recorded 440 mm of rain: a figure, equal to the annual amount of rain often recorded in some areas of the Imperia and the Côte d’Azur.
The system is currently swinging between the Savona area and the western Genoese area with particular criticality between Rossiglione and Campoligure. What should we expect? We are in what is the “prefrontal phase”, the most critical for our region from the point of view of hydrogeological effects, as the abundant rainfall tends to discharge on the same areas, thus putting the hydrographic basins under stress.
The situation will suffer an evolution only with the arrival of the libeccio which will be able to “unhinge” and therefore advance the line of static convergence that has been created between the sirocco and the north wind: from the late afternoon the front will move towards Genoa and the Levant with an intense phase, but also faster than that that we are seeing in the Ponente area.
At the origin of these extreme events there is always an excess of heat inherited fromyet another scorching Mediterranean summer that we have lived. There is a hand in climate change, therefore. We must not fear that from now on with every October disturbance there will be a flood event, but the conflict between sirocco and north wind, with the orography factor of our region, can always generate events like the ones we are witnessing. As evidence of the thermal energy involved, even in areas not yet affected by phenomena, relative humidity rates of more than 80% are observed today, combined with temperatures that I am not sure of these periods since they reach 25 degrees.
* forecaster, founder and president of Limet – Ligurian Meteorological Association