Weather: Next week, alluvial phenomena in Italy, some areas risk serious hydrogeological problems

Weather forecast for next week: still bad weather warningStill bad weather warning for most of next week on Italy. Given the particular synoptic conditions that will be created, some areas risk flooding and, consequently, serious hydrogeological problems due to torrential and repeated rainfalls. All this will also be accompanied by intense winds and a general drop in temperatures.

Already since Monday 28 November the descent of a powerful depression from Northern Europe, driven by air masses of arctic-maritime originwill cause the formation of a real Mediterranean cyclone capable of unleashing intense rainfall, even in the form of storm and accompanied by violent gusts of wind.Possible formation of a Mediterranean cyclone (B) during the next week
As we can see from the map below, the still too high temperatures (values ​​above the average of about 2/3°C) of the surface waters of our seas will provide that surplus of energy (in the form of latent heat and humidity) for the genesis of massive storm systems.Temperatures of the Mediterranean Sea still high and above the climatological averages
According to the latest updates there is the potential for extreme weather events and, given the type of configuration that will be outlined, the more exposed regions will be the southern ones and in particular Campania, Basilicata, Puglia, Calabria and Sicily where you risk problems from the point of view hydrogeological.
But what is meant by this term?“The hydrogeological risk corresponds to the effects induced on the territory by exceeding the critical rainfall levels along the slopes, the hydrometric levels of the watercourses, the minor hydrographic network and the disposal of rainwater.”
In simpler terms it means that in case of exceptional rainfall events (very intense rain of short duration) the ground loses its absorption capacity and therefore the water begins to flow quickly on the ground instead of penetrating it, causing flooding or, in the mountainous areas, dangerous landslides along the slopes.

The biggest risk with this type of disturbed inputs then concerns the possible stationarity of storm phenomena which could insist many hours/days always on the same areas. This is one of the potentially more insidious and dangerous configurations for some regions of our country: the utmost attention must therefore be paid to the possible triggering of the notorious self-healing stormswhich risk discharging 300 millimeters of rain in a few days (the equivalent of what usually rains in 3 months).
The depression front, in addition to a heavy wave of bad weather, will also be responsible for a thermal drop with the temperatures that they will bring below the reference climatic averagesespecially in the Centre-North.