Weather warning: Snow will fall in the southeast
From for
The situation
An active disturbance is coming from the Mediterranean Sea and will continue through this weekend.
The episode produced significant rainfall of 40 to 80 mm, locally up to 100 mm, in 36 hours along the coast of the Gulf of Lion and in the lower Rhône valley to the Provence Côte d’Azur.
At the same time, in contact with the cold air present in our regions, the snow falls in the south of the Massif Central, from the Cévennes to the Loire, from an average of 800 m. The highest snow accumulation is expected from Loser to Haute-Loire and Cantal, with thicknesses between 20 and 40 cm at 1000 m.
At medium and low altitudes, this first winter attack can cause traffic difficulties on the road network from 800 m. This wet, heavy and sticky snow can damage power lines due to its own weight and cause power outages in these areas.
A slow melt will push the rain-snow limit to 1100m this afternoon and 1300m on Sunday.
The sleet episode will nevertheless continue into Sunday evening, including the Southern Alps, but with less accumulation.
Observation
This Saturday
By 15:00, persistent rain of moderate intensity moved up from the Mediterranean east of Languedoc, Provence and the Cévennes, where snow fell from an average of 1,200 metres. Since yesterday, Coursegoules (06) has 30 mm, Bormes-les-Mimosas (83) 27 mm, Nîmes (30) and Sète (34) 17 mm.
at 12, the rain limit begins to rise. It is about 1,200 meters south of the Massif Center in Loser, and 800 meters in Haute-Loire and Aveyron, where the cold weather is more persistent. Snow accumulation reaches 5-10 cm at an altitude of 1300 meters. Precipitation increases near the coast between Languedoc and Provence / In the last 24 hours, 23.4 mm of rain fell in Cavalaire-sur-mer (83), 22.6 mm in Coursejoules (06) and 15 mm in Nimes (30).
at 9 o’clock Heavy snow falls in the Cévennes up to 900 meters above the Haute-Loire. Since yesterday, the layer has reached 15 cm on the top of Mont Aigoual, and 20 cm on Monts Loser. As for the rains, 16 mm of rain fell in Kavalaire sur mer (83) and 13 mm in Nimes (30) since yesterday evening. These precipitations are intensifying.
Evolution
This afternoon: the rains will be more severe and thunderstorms may start in the south of Var. As the snow rises to 1100 m, it also weakens in the Central Massif. Snow conditions are also noticeable in the southern Alps, which is good news for winter sports resorts in these regions. At the same time, an easterly wind blows steadily on the Côte d’Azur, with winds reaching 80-100 km/h on open headlands raising heavy seas.
Tonight and tonight Calm prevails in the Massif Central, where some snow falls from an average altitude of 1,300 meters. But strong stormy showers are still returning to Provence, especially Var.
Tomorrow is Sunday, a new widespread degradation occurs between eastern Languedoc and the Cévennes into the PACA and south of the Alps with the passage of a new very active rain-storm front. Heavy snow fell in the mountains, above 1100 meters in the east of the Central Massif, and above 1400 meters in the south of the Alps. By the end of the evening, conditions will improve with the evacuation of concern in the direction of Italy and Corsica, and this special press release will be lifted.
In this episode, we wait until Sunday evening:
– accumulation of rain Generalized up to 40-50 mm, locally 80-100 mm in the lower Rhône valley as well as in Provence.
– A lot of snow falls from 800 to 1300 m altitude south of the central massif. This wet, heavy and sticky snow can cause tree limbs and power lines to topple under its own weight. We expect 20 cm at 800 m, 30 to 40 cm at 1100 m, and sometimes 50 to 60 cm at altitude in the Cévennes (Mont Aigoual and Mont Lozère).
It should be noted that at the same altitudes, there will be plenty of snow in the Southern Alps, but its thickness will be slightly lower (40 cm of fresh snow in the resorts).
