A phenomenon will drop the temperature by 20 ° C this evening in the southwest

After one hot day, with peaks over 40°C over the southwest, a sudden phenomenon will cause the temperatures of the southwest to drop in the space of a few minutes. Around 8 p.m. this Monday evening, the winds will suddenly change direction: after blowing from the northeast since Saturday (and worsened the fires in Gironde), the winds will turn this evening to the northwest due to the rolling of the depression which is rising along the coast. This is the gallery, also called brouillarta. This coup de galerne is characterized by a sudden change, with the arrival of a air cooler and wetter on the Basque coast and the south of the Landes. This very sudden change will have two consequences: a dramatic drop in temperatures and a more humid atmosphere, without large precipitation however. This humidity and lower temperatures will be good news for firefighting, even if the change in wind can be quite violent in the evening.

The same phenomenon occurred at the end of the heat wave in June 18, with a sudden drop of 19°C in Biarritz in just 45 minutes. The galerne of this Monday, July 18 promises to be just as powerful, with possibly 15 to 20 ° C less in the coastal cities of the Atlantic, such as Biarritz and Biscarosse, and ten degrees less in Bordeaux.