Italy heading towards a stable week with high pressure, but nighttime temperature drop

The last autumn rainfall is leaving Italy, making way for a period of stable weather. On Sunday, October 25th, residual, modest, and irregular rain events will only affect Salento and the Tyrrhenian sectors of Calabria and Sicily in the morning, with light snowfall on the Alpine borders above 1,400–1,500 meters.

Starting Tuesday, October 27th, the meteorological situation will change radically. A solid high-pressure field (the Azores anticyclone) will extend over the Mediterranean, ensuring stable conditions and ample sunny spells across much of the country for at least three days. Maximum temperatures will rise, with peaks up to 24°C on the islands, while minimum temperatures will drop significantly due to nocturnal radiation, creating a daily temperature range of up to 14°C.

The arrival of high pressure marks a break in the typical autumn variability. The bad weather of recent days was caused by the passage of Atlantic disturbances, unstable air masses that bring rain and wind. These disturbances, like the one that affected the South, originate from the clash between warm and cold air masses and move from west to east following the westerly currents.

The Azores High is a semi-permanent high-pressure system over the Atlantic Ocean. When it strengthens and expands toward the Mediterranean, as expected from Tuesday, it blocks the passage of disturbances, ensuring clear skies and stability. This phenomenon is common in autumn and can last several days. However, clear skies favor strong heat dispersion at night (radiation), causing the marked drop in minimum temperatures and the significant temperature range forecasted. The situation could change again toward the end of the week with the arrival of a new disturbance front from northeastern Europe.