Temperatures drop: Arctic air descends at the end of the week!
After a heat peak that affected much of the country at the start of the week, the first true fall weather forecast looms over the weekend. A polar air landing will occur over our country. Large differences in temperature are a usual phenomenon in September, but after a long, hot summer, it may be surprising to find temperature levels not seen since last spring.
After breaking monthly heat records on Monday in the Southwest with up to 40 degrees Celsius locally in the shade, temperatures will eventually drop dramatically in the second half of the week. The weekend will be refreshing and in some areas we will lose up to 15°C in a few days.
Credit: The Weather Channel
Creation of a northern flow leads to lower temperatures from Thursday
From Monday to Wednesday, France is under the influence of an extensive low pressure system that stretches from Portugal to the Bay of Biscay. The general flow is southward and very hot air comes out of North Africa. Monday was the hottest day, but temperatures, albeit slightly cooler, will still be well above normal for the season through Wednesday. Note that the high temperature peak occurred at the same time just two years ago with 37.8°C on September 14, 2020 in Dax.
from Thursday An anticyclone will re-inflate over the British Isles while a depression will form between Scandinavia and Central Europe. Between these two systems, a northern flow will occur over France and significantly lower temperatures. It will be a polar antenna slope. The decline will begin Thursday in the northern half before generalizing to the entire country on Friday. The coming weekend will be cold with temperatures not exceeding 15 to 19 degrees Celsius in the afternoon over the greater northern half and 20 to 27 degrees Celsius in the southern part of the country. We will then be 3 to 4 degrees Celsius below average for the season. It will feel very fresh and exposed to the northeast wind. In the Mediterranean, Mistral and Tramuntana will blow hard, as will the westerly winds on Corsica.