Stable weekend, but first autumn thunderstorms from Tuesday.

The weekend concludes with stable and sunny weather across much of Italy, thanks to a persistent high-pressure system over the Mediterranean. Sunday, October 4th, is confirmed to be a predominantly clear day, with maximum temperatures in the inland areas of Central-Southern Italy reaching 26-28°C. Only some areas, such as the Western Alps, southern Sardinia, and southeastern Sicily, might see isolated showers.

However, meteorologists signal an incoming change. Starting from Tuesday, October 6th, simulations predict a weakening of the eastern edge of the anticyclone and the approach of an Atlantic trough from the west. This will bring a gradual worsening of conditions, with the first organized thunderstorms of the season potentially affecting especially the Tyrrhenian regions, marking an initial shift towards more autumnal weather.

The current weather situation is determined by the opposition between two major atmospheric systems. A broad area of low pressure dominates Northern Europe, with a vortex centered between Iceland and the British Isles bringing instability. In contrast, a robust high-pressure field extends over the central Mediterranean and Italy, acting as a shield, blocking the entry of more organized disturbances and ensuring stable weather.

This configuration, typical of late summer and early autumn, is responsible for the mild and sunny conditions of recent days. However, high-pressure systems are not eternal. The mathematical models simulating the evolution of the atmosphere are now beginning to predict a weakening of this anticyclonic shield on its eastern side. Simultaneously, the Atlantic depression to the north will manage to push a trough, that is, a tongue of unstable air, toward Italy from the west. The meeting of these different air masses is the mechanism that, step by step, generates disturbances and thunderstorms, marking the climatic transition toward the autumn season.