Of
Thursday January 9 at 6:00 p.m. au
Friday January 10 at 8:00 p.m.
Situation
A new Atlantic disturbance arrives this Friday morning in the northwest. Despite some uncertainties still regarding the precise trajectory of this disturbance, it will head towards the central regions during the day to reach the center-east in the evening.
In contact with the fairly cold air present in the eastern half of France, the rains will turn into snow on an axis going from the Breton and Norman hills to the Center region and the northern plains of Auvergne then Burgundy. .
This episode begins at 6 a.m. in the northwest, spreads in the morning towards the Central region, and reaches Burgundy in the afternoon, the risk period being especially between 6 a.m. and 10 a.m. on the Normandy and Maine hills. .
This development is not particularly aggravating. The snow will remain on the ground mainly on the hills (above 250 m altitude). A sprinkling will concern the Central region. Then a few centimeters will also stick to the ground on the first heights of Burgundy and Auvergne. In addition, accumulations will remain low in general.
At the same time, flooding continues on rivers already placed on alert by the Vigicrue flood monitoring organization. Water levels will even continue to rise but this Friday’s disturbance is the last before the return of dry weather for at least ten days from now on.
Observation
This Thursday is marked by an improvement in weather conditions. Light residual snowfall is still occurring near the Ardennes while there are showers in Hauts-de-France. Temperatures peak between +1 and +4°C in these areas in the afternoon but the drop is expected to be rapid in the evening and at night with clear skies.
We expect fairly severe frosts in Hauts-de-France, particularly in areas where the soil is snow-covered. It will be -1 to -5°C this Friday morning. In this context, we must be wary of the refreezing of wet/snow-covered roads with the formation of patches of ice.
Evolution
Friday morning
The rain-snow disturbance is present from the end of the night (between 4 a.m. and 6 a.m.) and begins to transform into snow in the Breton hills then in Lower Normandy (South of Manche, Orne, south of Calvados, Mayenne and Sarthe especially Snow is also falling on the plains in the Loire Valley and will spread quickly to the Central region.
The period most at risk is therefore between 7 a.m. and 10 a.m. in all these areas. Snow depths could reach 3 to 7 cm in the hilly areas of these departments placed on orange alert, and occasionally 10 cm in the highest areas.
At the same time, after a cold night and severe frosts (-3 to -5°C), we must be wary of icy conditions in Hauts-de-France, particularly in the Nord and Pas-de-Calais, where the network road was still wet and locally snowy.
Friday at midday
-Light snow falls from Lower Normandy to Central and northern Auvergne, reaching western Burgundy. Intensities weaken, often with rain mixed with snow. A dusting of 1 to 3 cm is however expected on this axis (with 5 cm probable in the hilly departments).
Note that snowflakes can also fall in Beauce and the southwest of Ile-de-France (Sud-Yvelines, Essonne), while remaining very weak.
Friday afternoon:
Light to moderate snowfall falls mainly in Burgundy and Franche-Comté and brings a dusting (1 to 3 cm) above 400 m altitude).
Everywhere else, the episode ends with some drizzle from Normandy to the Center and northern Auvergne due to the slight daytime mild spell.
In the evening, conditions are improving, except between the Jura mountains and Haute-Savoie where it snows lightly from 500 to 600 m altitude, without any aggravating character.
Temperatures will remain positive overnight and there is no fear of icy formation in wet areas.
This development is not particularly aggravating. The snow will remain on the ground mainly on the hills (above 250 m altitude). A sprinkling will concern the Central region. Then a few centimeters will also stick to the ground on the first heights of Burgundy and Auvergne. In addition, accumulations will remain low in general.
On this episode, we expect:
– ground hold in the morning on the hills (between Brittany, Orne and Sarthe) with locally 5 cm.
– a dusting of 1 to 3 cm over the central region in the morning.
– a ground hold of 1 to 5 cm on the heights of Burgundy and the first Auvergne hillsides from 400 m in the morning, with mild temperatures in the afternoon.
Persistence of black ice Friday morning in Hauts-de-France, in particular the Nord and Pas-de-Calais, on the network still snowy and/or wet due to refreezing during the night.
At the same time, flooding continues on watercourses already placed on alert by the Vigicrue flood monitoring organization. Water levels will even continue to rise but this Friday’s disturbance is the last before the return of dry weather for at least ten days from now on.
