Corsica, Aube, Haute-Garonne, Loire-Atlantique, Charente-Maritime… Many cities saw their monthly temperature record fall in October. On Sunday October 16, from the Gironde to the Pyrénées-Atlantiques and the Hautes-Pyrénées, the 30°C threshold was even often crossed.
If it is not uncommon to see such temperatures in the Southwest until the end of October, the episode of mildness in progress for ten days is “remarkable for its duration on the scale of the country” underlines Météo-France.
“After October 15, days with an average temperature above 18°C (typical of mid-September) are rare. Given the forecasts, 2022 should total between 9 and 15. Old record: 3 days in 2014”, recalls on Twitter Gaétan Heymes, forecasting engineer at Météo France. For the experts there is no doubt: there is a very good chance that October 2022 will become the hottest month of October observed in France.
heat feather
After the heat domes, induced by climate change, which have suffocated Europe and North America for the past two years, France is facing its ninth anomaly of more than 4 degrees of the year. The phenomenon, called a heat plume, is caused by a flow of very mild south-westerly air from the Canaries and the Iberian Peninsula, which has been rising since mid-October over a large part of the country, summarizes Meteo France. It is associated with a vast low pressure zone which extends over the near Atlantic and generates cyclonic winds. The cold drop isolation of the Atlantic depression favors other warm thrusts for this week.
“In summary, the [les] #HeatPlumeThis week’s heat is the result of a planetary scale dynamic wave circulation originating in the Pacific, with amplification over the Atlantic along the wave propagation.” explains climatologist Christophe Cassou, lead author of the 6th IPCC report. However, “the very hot south-west to south flow should continue until the end of the month, or even increase next week with unusual heat”, warned Sunday, October 23 the observatory of tornadoes and violent thunderstorms Keraunos.
The specter of drought
This episode is part of a context of “visible climate change” specifies Météo-France. “We already know that heat waves, in addition to being more frequent and more intense, become earlier and later, like the one we have just observed,” adds the meteorological service. According to the latest report from the Weather Channelthe phenomenon should continue this week when temperatures around 30°C are expected in the South-West and locally 25°C in the north.
“The hot anomaly that we are experiencing, with average temperatures exceeding normal daily by +3°C, could even reach peaks above +5°C.” until the end of the month, and its possible extension until the beginning of November”. These temperatures do not bode well for soil water reserves. There is indeed a correlation between abnormally high temperatures and lack of water.
According to the Bureau of Geological and Mining Research (BRGM), a public establishment which manages the resources and risks of the soil and subsoil, the majority of the water tables in France continued to empty in September. However, the rains are currently not sufficient to recharge the groundwater which needs it during the fall.