Next week: severe weather with strong winds, heavy rain and snow
Why does weather create a severe weather hazard?
Low pressure situation in Europe next week © Weather Channel
A large low pressure system will affect Western Europe early next week. Mighty altitude jet stream will deepen dramatically and fuel depressions that will become more active with heavy rains, strong winds, and snow in the mountains. The exact trajectory of these depressions has yet to be determined, but recent atmospheric modeling suggests that the southern part of the country will be at the forefront of bad weather. Heavy rain is expected in the southwest, heavy snow on all terrains, and strong wind on the Atlantic and Mediterranean coasts. In the context of such weather, our services will have several days’ notice and will be in place between Monday and Wednesday for this bad weather episode.
Heavy rains in the southwest
Heavy rain will fall in the south-west next week © Weather Channel
The most active disturbances in this very dynamic northwesterly flow will be in the southwestern part of the country with showers in the first half of the week. As is often the case with this type of sea flow, the accumulation of rain in the foothills of the Pyrenees will be most important, blocking it. In the Basque country and the foothills of the Pyrenees, we expect from 100 to 140 mm, ie. It is equivalent to almost a month’s rainfall in 3 days. There is a possibility of flooding and flooding in the waterways of the Adur Garon basin. From a general perspective, total rainfall expected across the great southwest will average 50-60mm between Monday and Wednesday, equivalent to 15 days of rain. In some sectors, such as Toulouse, where the lack of rain has been significant for several months, these will be very beneficial rains. It should be noted that rainfall accumulation will be less important in the Roussillon plain, where the expected few rains will not be enough to stop the severe drought in this region.
Heavy snow fell on our mountains
With the arrival of maritime polar air over France, the air mass will be cold and wet enough to bring snow to any elevation in the mountains. With a disturbed regime from the west to the northwest, the snow cover will fill all our massifs. The greatest amount of snow will be in the Pyrenees, the Massif Central and the Alps, although it is still difficult to determine the amount of snow. However, we can predict some average snow accumulations for the first part of the week: 60-90 cm in the Pyrenees at 2000 m, 40 – 50 cm in the Massif-Center at 1400 m, 30 – 60 cm in the Alps at 1800 m, 15 – 30 cm at 1200 m in the Vosges and Jura. Sometimes with strong winds, weather conditions blizzard can be observed in open ridges and plateaus. Also, beware of the risk of snowfall, which can cause problems on mountain roads. Access to stations at certain altitudes may be temporarily difficult.
Bad weather next week © Weather Channel
It can be cold and snowy down to the plains
The drop in temperatures that will begin on Sunday will gradually increase next week with the installation of a north-northwest current, which is increasingly provided with cold air. Therefore, we will initially find the seasonal temperature between Sunday and Monday. Our national heat index (an average of forecast temperatures for 30 cities in France) shows that temperatures will drop below normal for the season from Tuesday, with calmer and drier weather likely to bring a chill later in the week. weather condition. We have to go back to December 18th to find below-normal temperatures for a season marked by record mildness in France in the last decade of December and the first decade of January.
© Weather Channel
As for the risk of snow and temperature levels in the plains, some plains regions may be affected by snow, especially between Tuesday and Thursday.
We’ll see a risk of snow on the plains in the central regions on Tuesday, which will sweep across much of the southern half of the country. The south of Centre-Val de Loire and Bourgogne-Franche-Comté and Auvergne-Rhône-Alps are the areas most affected by lowland snow according to our latest forecast models, but it is too early to pinpoint these areas. expected quantities. Snow may also fall in the form of sleet near the English Channel and in the northeast. Reliability becomes more limited on Wednesday, but the risk of snow on the Plains may continue from northwest to central.
Bad weather next week © Weather Channel
Strong winds in the west and south
If strong winds on Monday can disturb many regions under the influence of the depression in the North Sea, especially our coasts, special monitoring of the situation is required especially on Tuesday. a depression that can be described as depression bomb will expand rapidly near the Atlantic Ocean under the influence of the strong Jet Stream (a strong current at high altitude). Its exact trajectory is still somewhat uncertain, but it should reach the Atlantic coast late Monday into Tuesday night. It is expected that the strongest wind will blow in the south of the trough. At present, the coasts of Aquitaine and Charente are most exposed to stormy winds (100-120 km/h). Strong winds of 80-100 km/h are possible on Tuesday morning in southwestern areas. Strong winds will reach the Mediterranean from Tuesday afternoon to late night. They will be able to exceed 100 km/h on the most exposed coasts, with the risk of reaching 130-140 km/h at the ends of Corsica.
After a very unsettled first part of the week with bad weather, the weather should calm down considerably in the second part of the week as the depressions subside. With calm and dry weather, cold will increase with frequent and sometimes severe frosts, especially on snow-covered lands.