Subtropical anticyclone brings anomalous heat to Europe and Italy at the end of September

In the last days of September the atmospheric circulation on the European continent will be characterized by the recovery and northward expansion of a subtropical anticyclonic promontory.

Lorenzo Tedici, media meteorologist at iLMeteo.it, confirms that the structure will determine marked positive thermal anomalies over central-western Europe, with deviations of up to +8-10°C above the averages for the period between France and Germany.

In Italy the influx of hot air will bring the maximum daytime values ​​to levels 3-4°C higher than the climatological averages for the end of September: maximum temperatures of up to 26°C are expected in Milan, 28°C in Aosta and 29°C in Rome.

Removal of residual instability and stability phase

After the definitive removal of the rapid disturbance that occurred in the last few hours, the last residues of instability will be recorded on Saturday morning between Salento, Calabria and Sicily, with isolated rainfall in the afternoon on the southern Calabrian sector and on Ionian Sicily.

On Sunday only brief and local phenomena will be observed in southern Sicily. Starting from the weekend, the consolidation of high pressure will favor conditions of general atmospheric stability across the entire national territory at least until October 1st.

Trend of maximum temperatures and trend for the beginning of October

Daytime temperature values will record locally marked increases. On Saturday the highest values ​​will be measured in Oristano (30°C), Cagliari (29°C) and Aosta (28°C). Maximum temperatures of up to 28°C are expected in Aosta, Florence and Sondrio on Sunday. On Monday the values ​​will reach 30°C in Oristano and 29°C in Benevento and Florence, while on Tuesday a further increase is expected with values ​​up to 31°C in Oristano, 30°C in Terni and 29°C in Rome.

For the first days of October, the modeling simulations hypothesize the approach of a disturbed system of Atlantic origin, with a possible increase in instability starting from the Major Islands and a subsequent extension of precipitation to the rest of the Peninsula by Sunday 4 October. Since these are medium-term projections, the picture will require further confirmation in future updates.

In detail

Saturday 26. In the North and Centre: stable and sunny weather. In the South and on the Islands: residual instability in the morning between Salento, Calabria and Sicily, with local rainfall in the afternoon on the Ionian and southern sectors; general improvement in the evening.

Sunday 27. In the North and Centre: mostly stable and sunny weather. In the South and on the Islands: mostly clear or slightly cloudy skies, except for local and brief showers in southern Sicily.

Monday 28. Stable and sunny weather in all regions. Maximum temperatures increasing, with widespread values ​​above seasonal averages.

Trend: possible entry of an Atlantic disturbance starting from the Major Islands in the first days of October, with potential extension of the front to the remaining national territory by Sunday 4th.