The atmospheric circulation over the Mediterranean basin sees the isolation of a cyclonic structure located west of Sardinia. This configuration conveys a constant flow of humid southern currents in the middle and lower layers towards the north-western sectors of the Peninsula and the Major Islands. In the remaining areas of the national territory, conditions will remain stable and without significant precipitation.
The increase in cloud cover in the North will limit night-time heat dispersion, resulting in minimum values in the plains of between 7 and 10°C compared to maximums of between 12 and 16°C. In the central regions, temperatures will be between 9 and 12°C in the morning and between 17 and 20°C in the afternoon, while in the South and on the two major islands the minimums will be between 13 and 16°C with maximums between 18 and 23°C.
Distribution of precipitation, ventilation and sea state
On Thursday 5 November the depression structure will gradually move its range of action towards the Peninsula: heavy rainfall will affect eastern Sardinia (100-150 mm/24h) and south-eastern Sicily (30-50 mm/24h). The phenomena will also extend to Western Liguria, Piedmont and Valle d'Aosta with accumulations between 5 and 15 mm/24h. A dry picture with passing clouds will characterize the North-East, the Adriatic regions and the Ionian sector. The ventilation will be eastern, with gusts estimated up to 60-70 km/h between Savonese and Imperiese and between 40 and 50 km/h on Sardinia. The wave motion will present very rough sea conditions with significant wave heights between 1.5 and 2.5 meters on the western Ligurian Sea, remaining below 2 meters on the basins surrounding Sardinia.
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.
Evolution between Friday and the weekend
During Friday 6 November the unstable system will move towards the central regions, resulting in moderate rainfall (10-20 mm/24h) concentrated along the Tyrrhenian belt between Lazio and Campania. The influx of colder air masses will favor a thermal decline of 3-5°C along the central Apennine ridge, with snow levels decreasing up to 1000-1200 meters and generally limited accumulations of between 2 and 5 cm above 1300 metres. On Saturday the disturbance will gradually move away from Italy with residual showers in the Centre-South and large clearings in the North-West. From Sunday the definitive removal of the trough towards the east will emerge, favoring the restoration of stable conditions with thermal values aligned with the climatic averages of the autumn period.
IN DETAIL
Thursday 5. In the North: compact clouds in the west with scattered rain between Western Liguria, Piedmont and Valle d'Aosta (5-15 mm/24h, around 10 mm in Cuneo); dry in the North-East; wind from the East with gusts of up to 60-70 km/h on the western Ligurian Sea and very rough seas with waves of up to 2.5 metres; maximum between 12 and 16°C. In the Center: slightly or partially cloudy along the Adriatic coast; more significant accumulations on the Tyrrhenian coast with absence of significant precipitation; maximum temperatures between 17 and 20°C. In the South and on the Islands: rainfall in eastern Sardinia (100-150 mm/24h) and central-eastern Sicily (30-50 mm/24h); dry on the peninsular regions; gusts from the East up to 40-50 km/h on Sardinia; maximums between 18 and 23°C.
Friday 6. In the North: overcast skies in the west with scattered rain between Liguria and Piedmont (5-15 mm/24h, around 10 mm in Cuneo); cloudy with no precipitation in the North-East; maximum between 12 and 15°C. In the Centre: increasing clouds with widespread rainfall along the Tyrrhenian sector between Lazio and Umbria (10-20 mm/24h); temperature drop of 3-5°C at altitude with snowfall on the central Apennine mountains at altitudes of 1000-1200 metres; maximums around 15-18°C. In the South and on the Islands: scattered rainfall on the Ionian side of Sicily (10-20 mm/24h, around 15 mm in Catania) and on Campania; dry variability elsewhere; moderate ventilation with gusts up to 30-40 km/h and rough seas.
Saturday 7. In the North: weak residual rainfall in Emilia-Romagna (2-5 mm/24h); large clearings in the remaining sectors; maximums between 13 and 16°C. In the Centre: residual rainfall in the Tyrrhenian area (3-7 mm/24h) and isolated light showers between Umbria and the interior of Lazio (less than 5 mm/24h); maximum stationary at 16-18°C. In the South and on the Islands: variability with weak phenomena scattered between Campania and Calabria (5-10 mm/24h); extensive clearings on the Major Islands; Mistral ventilation with gusts of up to 40 km/h on the channels of the Major Islands.
Trend: removal of the unstable structure starting from Sunday 8th with large sunny spells across the entire national territory and stationary temperatures in line with seasonal averages.
