The weather, Atlantic flow towards Italy: two disturbances with widespread rainfall

The meteorological context over the central Mediterranean basin is determined by the entry of humid and unstable Atlantic currents. Federico Brescia, meteorologist at iLMeteo.it, explains that the baric structure outlined by the numerical models highlights the transit of two distinct perturbed fronts during the week: the first will affect the Peninsula between Monday 9th and Wednesday 11th November. While the second pulse, characterized by a more marked baric gradient, will determine widespread rainfall between Thursday 12th and Friday 13th.

The beginning of the week will see an increase in cloud cover in the North with scattered precipitation between 10 and 20 mm/24h and snow level in the Alps between 1500 and 1700 metres. Maximum temperatures in the plains will be between 10 and 14 degrees. In the Centre, cloud cover will increase on the Tyrrhenian side in an initially dry context (maximums between 13 and 17°C), while in the South and on the Islands stable conditions will be observed with large clearings and daytime values ​​between 18 and 21°C.

On Tuesday 10 November, the advancement of the first disturbance will determine rainfall between 5 and 15 mm/24h in Liguria and central regions, compared to dry variability in the South with stationary temperatures. On Wednesday 11 November, the phenomenology will show a resurgence in the sectors exposed to southern flows: in Liguria, in particular in the La Spezia area, rainfall amounts of between 50 and 70 mm/24h will be recorded. In the Center the instability will affect upper Tuscany with showers estimated between 30 and 50 mm/24h, while in the South little or partially cloudy skies will prevail. The southern ventilation of Scirocco and Libeccio will record gusts between 40 and 50 km/h, with growing wave motion and significant wave heights of between 1.5 and 2 meters on the Ligurian Sea and the Tyrrhenian Sea.

The entry of the more structured disturbed front is expected on Thursday 12 November, harbinger of widespread precipitation in the Centre-North: in Liguria the possibility of storm-like precipitation with accumulations of between 100 and 150 mm/24h is estimated. The ventilation will present a significant reinforcement with Libeccio gusts up to 60-70 km/h and swell up to rough seas, with waves between 2.5 and 3 meters in the open sea.

Regarding the evaluation of the hydrogeological and hydraulic criticalities connected to the relevant rainfall contributions and the state of the sea, please refer to the consultation of the official bulletins issued by the Civil Protection.

The instability will persist between Friday and the early hours of Saturday in the central-southern regions, and then give way to a gradual improvement from Saturday afternoon with the removal of the disturbance towards the east.

In detail:

Monday 9. In the North: very cloudy skies with scattered rain (10-20 mm/24h); snow in the Alps between 1500 and 1700 metres; maximum temperatures between 10 and 14°C. In the Center: increasing clouds starting from the Tyrrhenian side; dry with clear spells along the Adriatic; maximums between 13 and 17°C. In the South and on the Islands: stable and sunny conditions; light winds and highs between 18 and 21°C.

Tuesday 10. In the North: overcast with light or moderate rainfall in Liguria (5-15 mm/24h); dry in the remaining sectors with irregular clouds; maximums between 11 and 14°C. In the Centre: widespread clouds with scattered rainfall between 5 and 15 mm/24h, most likely between Tuscany, Umbria and Lazio; maximums between 14 and 17°C. In the South and on the Islands: dry variability without precipitation; stationary temperatures with maximum values ​​around 18-20°C.

Wednesday 11. In the North: overcast with widespread rainfall in Liguria, significant in La Spezia (50-70 mm/24h); partly cloudy elsewhere; Scirocco gusts up to 50 km/h; maximum temperatures around 12-15°C. In the Centre: cloudy skies with marked instability in upper Tuscany associated with showers between 30 and 50 mm/24h; weak isolated showers on the rest of the Tyrrhenian sector (less than 5 mm/24h); maximum between 15 and 18°C. In the South and on the Islands: slightly or partially cloudy with medium-high clouds; increasing swell with waves up to 2 meters on the island channels; maximum stationary at 19-21°C.