The weather forecast was however clear for this weekend of August 15: big blue sky, great sun, heat wave, and perhaps still a few clouds on Brittany. But what was their surprise of the inhabitants and the holidays of the west of France when they woke up on Friday morning with a sky … graying with orange yellow reflections.
Loire-Atlantique, Brittany, even the department of Sarthe is concerned. Rebelote for the day of Saturday, this veil through which we can still see the sun try to break through, is always very present.
Fires in Portugal, Spain, but also … in Canada
No fire in the west of France at the moment, so you have to get further to find the reasons. Several causes are advanced by meteorologists. First, the fires currently affecting Portugal, as well as northern Spain. The fumes then go back from the Iberian peninsula through atmospheric currents.
Breton time explains: “They are so important that they generate vast smokes that spread in the Gulf of Gascogne to Brittany. »»
According to the European Observatory Copernicus, these smoke could be added those of the current fires in Canada. The country is undergoing this year the second worst season of forest fires in its history with 7.5 million hectares of burned forest.
Pollution in large cities
Another track also advanced by specialists: sahara sand dust. A phenomenon that is not new in the west of France.
For major cities, another explanation can be added to these, especially for Le Mans: air pollution. Since August 9, air quality has been considered degraded. Among pollutants, ozone, whose reactions are amplified by ultraviolet solar radiation.
In some cities, such as Quimper, this veil that covers the sky made it possible to limit the expected heat for this long weekend. “We have in the atmosphere of smoke, which veils Quimper and absorbs the rays of the sun which reach the ground. It can reduce the temperature, and move away from potential records, “said Breton meteorologist, Steven Tual, to Ouest-France.