Of
Wednesday January 8 at 9:00 a.m. au
Thursday January 9 at 9:00 a.m.
Situation
A depression associated with a major conflict of air masses crosses the northern half of France this Wednesday. It brings sustained rains between Brittany, Pays de la Loire and Lower Normandy on already saturated soils. With the cold air holding up north of the Seine, snowfall is expected between Upper Normandy, Hauts-de-France and the Ardennes between Wednesday afternoon and Thursday morning.
This situation requires a special press release with possible accumulations of 4 to 8 cm, locally 10 cm on the Normandy hills, the Picardy plateaus up to Artois, by early Thursday morning. A significant risk of icy conditions is also present early this Thursday morning.
Observation
This event has not yet started.
Evolution
The highest risk period extends from Wednesday 3 p.m. to Thursday 12 a.m.
From the morning of this Wednesday, the rains are copious in the northwest and all the departments placed on YELLOW rain alert. We expect intensities of more than 10 mm/h, particularly in Morbihan and southern Finistère.
The disturbance crosses the Seine at midday, with precipitation starting to fall in solid form due to temperatures close to 0°C. Snow falls throughout the afternoon in Nord-Pas-de-Calais, with increasingly easier hold on the ground thanks to the isothermal phenomenon.
During the evening and night, the disturbance gradually evacuates towards Belgium and the intensities weaken. Snow showers are still possible until late night and early morning of Thursday on the Picardy plateaus, then icy conditions could set in until 8-9 a.m. Thursday.
In total for the episode, we expect:
– up to 50-60 mm of rain in Morbihan, a little less in the other departments in YELLOW rain, but given the saturated soils and rising watercourses, vigilance is required.
– up to 3 to 5 cm of snow in the departments placed on YELLOW snow level alert.
– up to 10 cm in the departments placed on ORANGE snow level alert.
France
