WEATHER: an unstable anticyclone and a furious Atlantic, is the worst yet to come?

The last period of October is proving to be particularly dynamic from a meteorological point of view, with Italy in balanced between the influence of a robust anticyclone and the risk of torrential rain. This atmospheric scenario is typical of the seasonal transition, when the balance between high and low pressure becomes unstable and the Mediterranean takes on a crucial role in determining weather conditions.

In detail, the presence of a vast anticyclonic field positioned on the central Mediterranean, it is guaranteeing, for now, a stable and rather mild climate over much of the peninsula. Temperatures remain above seasonal averages, especially in the Centre-South, where maximums reach up to 25°C. However, the anticyclone is starting to show signs of weakening, leaving Northern Italy exposed to the first infiltrations of colder and more unstable air of Atlantic origin.

The comparison between these two atmospheric systems is revealing crucial for the formation of extreme meteorological phenomena. On the one hand, the anticyclone, which is acting as a block, temporarily prevents Atlantic disturbances from advancing towards the central Mediterranean. On the other hand, these disturbances accumulate and, as soon as they find an opening, can generate episodes of intense bad weather. This is precisely the risk that looms over the next period, with the danger of torrential rains and storms.

The Mediterranean, still relatively warm at this time of year, favors atmospheric instability. The humid and unstable currents coming from the Atlantic, coming into conflict with the warmer air stationed over the sea, generate strong thermal contrasts, which often lead to the development of violent storms. These storms, if accompanied by strong winds and convergences of moist air, can give rise to phenomena of Mediterranean cyclogenesisi.e. the formation of atmospheric depressions that intensify bad weather phenomena.

In particular, some Italian regions are more exposed to these phenomena. Liguria and the Upper Tyrrhenian Sea, for example, are high risk areas at this time of year. Here, the mountain ranges overlooking the sea can trigger the so-called stau effect, i.e. the forced lifting of humid air masses coming from the sea, which cool rapidly giving rise to heavy rainfall concentrated in short periods. When these rains become torrential, they can cause flash floodsone of the most dangerous situations in our area.

Another aspect to consider is thehigh rainfall accumulation capacity. Forecasts indicate that some areas could receive an entire month’s worth of rainfall in the space of a few hours. In these conditions, the soil, already saturated, is unable to drain excess water, increasing the risk of landslides and landslides, especially in hilly and mountainous areas.

At the same time, the South and the larger islands still remain under the influence of the anticyclone, which maintains stable conditions and temperatures above normal. However, rapid deteriorations cannot be ruled out in these areas too, especially in the second part of October, when Atlantic disturbances could undermine the resistance of the high pressure and bring bad weather also in the Centre-South.

The situation requires great attention, especially because the combination of heavy rains and already saturated soil could lead to phenomena of hydrogeological instability. Local authorities and Civil Protection are carefully monitoring the forecasts, inviting the population of the most at-risk areas to take the necessary precautions.

The weather trend at the end of October therefore remains uncertain and strongly linked to the evolution of Atlantic disturbances. If the anticyclone were to resist, we could see a phase of stable and sunny weather, with temperatures above normal. However, if high pressure gives way, the risk of storms and floods will become concrete, especially in the northern and Tyrrhenian regions.

In conclusion, the end of October will be a meteorologically delicate phase, characterized by a clear contrast between anticyclonic stability and the risk of extreme bad weather. It remains essential to follow the forecast updates and pay attention to any weather warnings, since in a few days we could go from an almost summer climate to torrential rains and extreme phenomena.