Weather report. Are we heading for a major heat wave next week? – West France

After the gloomy passage of the middle of the week, the good weather and the heat should return to France on June 11 and 12, with a mercury climbing up to 25°C in the north of France and 35°C in the south. But these temperatures could only be a lukewarm appetizer of those that France will experience from Wednesday June 15. “Could”. The conditional is important because weather models still differ on the magnitude of this heat peak. And they diverge in unprecedented ways. We explain why. What are the different models predicting for next week? Thus, according to maps of the American forecasting model, relayed on Twitter by the Breton meteorologist Steven Tual, it could be up to 44 ° C in Nantes on Saturday June 18. An exceptional temperature for this time of year. Agate Météo also mentions on Twitter the possible occurrence of very high temperatures at the end of next week, in the south-west of the country but not only. But, as Yann Amice, meteorologist for our partner SportRizer, notes, the European model, which Météo France uses to establish its forecasts, “is not as categorical”. Concerning Nantes, this model indeed evokes a temperature of 28° C on Saturday June 18. Why such a difference in estimate? As Météo Villes explains in particular, these differences in estimates are linked to the fact that the American and European models do not currently agree on the future of a “cold drop” currently located off the coast of the Iberian Peninsula. . As we explained to you last July in an article dedicated to the phenomenon, a cold drop “is a cold mass, rather circular in shape, which was formed at altitude by escaping from the reservoir of air which still remains at this time of year at the North Pole. The presence of these air masses has important consequences on the rest of the meteorological situation, by creating instability where they are present and by modifying the air flows in the surroundings. And in this case, in mid-June 2022, this mass of cold air blocked in the Atlantic, contributes, according to Météo-Villes, “to promote the rise of very hot air from northern Africa towards the Iberian Peninsula”. In fact, in the latter, scorching temperatures have already been announced, recalls weather journalist Guillaume Séchet on Twitter. The mercury will thus be able to exceed 40°C in Andalusia. And if these temperatures continue, Spain could therefore experience its first heat wave of the year. However, according to the American model, this cold drop would come a little closer to Portugal in the coming days, which would contribute even more to bringing African air up to Europe. And, in this case, “temperatures can actually soar”, notes Yann Amice. But the European model, instead, sees this cold drop disappear, which would limit the rise of this very hot air mass from the Maghreb. What are we sure of now? If the extent of this heat peak remains to be determined, one thing is certain: heat there will be. After a brief and slight cooling on Monday and Tuesday “temperatures will rise in the second part of the week”, cautiously confirms François Long, forecaster at Météo France. “We must expect a rise in temperatures which will spread to all regions from the middle of next week”, abounds Yann Amice. Wednesday, June 15, on the southern half, we could thus “observe 30 ° C while in the north the temperatures will remain between 22 and 25 ° C. “And, for the rest, we will have to wait to find out which model wins… Weather forecast. Are we heading for a major heat wave next week?