Those hoping for a sunny weekend may have to rethink their plans. In fact, between Saturday 7 and Sunday 8 November, Italy is preparing to be crossed by a so-called “cold drop”, a colder air mass at altitude destined to move from the north-west to the south-east, bringing conditions of atmospheric instability. The worsening will be caused by the arrival of cooler and more unstable currents from the Atlantic, which will favor the formation of a low pressure area on the Tyrrhenian Sea. The result will be a rather rapid disturbance, concentrated above all on the central-southern regions, with showers, thunderstorms and snowfall at the highest altitudes of the Apennines.
Saturday 7 November: rain and thunderstorms in the Centre-South
Saturday will be the busiest of the weekend. The low pressure vortex on the Tyrrhenian Sea will initially favor rainfall in Emilia-Romagna, Marche and Abruzzo, which will extend towards Lazio and Campania as the hours pass. Rome and Naples could also be hit by showers and thunderstorms, with average accumulations of between 15 and 25 millimeters of rain in 24 hours and local peaks of up to 30-40 millimetres.
In the North, outside the areas affected by the worsening, the weather should remain mostly dry, with even large sunny spells. To find out about any hydrogeological alerts and critical issues, it will be important to consult the official Civil Protection bulletins.
The snow also returns to the Apennines
The worsening will lead to a drop in temperatures at altitude, sufficient to encourage the return of snow along the ridges of the Tuscan-Emilian and central Apennines, especially above 1,700-1,900 metres. Accumulations expected will generally be modest and concentrated on the highest peaks.
The wind will also contribute to making Saturday more eventful, with Mistral and Ponente gusts of up to 40-55 km/h on the Tyrrhenian Sea and in the channels of the Major Islands. Western seas will become rough or very rough, with waves up to 2.2 meters high.
Sunday 8 November: the sun returns (almost everywhere)
The good news for those who have organized a Sunday trip is that the worsening should not last long. The expansion of high pressure from the Atlantic will in fact favor a progressive improvement over much of Italy. Some residual rain could still affect Salento and southern Calabria, especially Reggino, especially during the morning. However, these will be weak and isolated phenomena, destined to attenuate by the afternoon.
In the rest of the country, clear or slightly cloudy skies will prevail, with large sunny spells. The wind will also lose intensity and the seas will tend to become less rough.
Temperatures up to 20 degrees, but be careful of the fog
Despite the arrival of cooler air at high altitude, maximum temperatures will remain close to seasonal averages: between 13 and 15°C in the North, 14-18°C in the Center and up to 18-20°C in the South and on the Major Islands. With the return of high pressure, however, another typically autumnal phenomenon could appear: fog.
Between the late evening of Sunday 8th and the early hours of Monday 9th November, the nocturnal cooling and weak winds will favor the formation of banks of fog and even dense mists on the northern plains and in the internal valleys of the Centre. Visibility could therefore reduce locally, especially in the early hours of the morning. In short, it will be a weekend with two sides: Saturday with rain and thunderstorms especially in the Centre-South, Sunday with a widespread improvement.
