Weather: there is a risk of storm for Friday, with gusts up to 120 km/h

After several weeks of relatively peaceful weather conditions, France is preparing to return to significantly more turbulent weather.

From Wednesday, Atlantic disturbances should follow one another, bringing with them rain and wind. But it is above all the day of Friday October 23 that attracts the attention of forecasters, with the possibility of a first stormy episode this fall.

A hollow depression expected over the Atlantic

At the origin of this deterioration, a depression could form in the near Atlantic before quickly reaching the south of England.

Its development would be favored by a powerful jet stream - a very fast and narrow flow of air which circulates from West to East - at altitude, while the significant differences in atmospheric pressure around its center would contribute to strengthening the winds at ground level.

Some weather models envisage a minimum pressure close to 975 hectopascals (hPa), significantly lower than the average atmospheric pressure of 1013 hPa.

A deepening sufficiently marked to raise fears of violent winds, even if forecasts still differ on the exact intensity and trajectory of this depression.

Gusts of up to 120 km/h on the Channel coast

Brittany, Normandy and Hauts-de-France would be on the front line, particularly on the Channel coasts.

From the night of Thursday to Friday, gusts could reach 100 to 120 km/h on the most exposed coasts.

Inland, peaks of 80 to 90 km/h are expected, or even more locally.

The phenomenon could also concern the Pays de la Loire, Centre-Val de Loire and Île-de-France, where gusts would reach 60 to 80 km/h.

However, these estimates remain provisional.

The strength of the winds will closely depend on the depth of the depression and its path, two parameters on which the different weather models do not yet agree.

Storm or simple gust of wind?

Four days before the deadline, the risk of a stormy episode is well identified, although it is not yet possible to precisely determine its extent.

A movement of a few tens, or even a few hundred kilometers, of the low pressure center would be enough to significantly modify the distribution of the most violent winds and, consequently, the regions concerned.

The period calls for all the more vigilance as the trees still retain a large part of their foliage.

Their wind resistance is therefore greater, which increases the risk of branches falling during strong gusts.

The episode could also complicate the travel of All Saints holidaymakers.

Traffic difficulties are particularly expected on exposed roads and bridges, while maritime connections could be disrupted.

Water activities are also likely to suffer from particularly rough seas.

The next 48 hours should make it possible to refine the forecasts and determine whether France will experience its first real storm of the fall on Friday.

If the phenomenon is officially qualified as a storm, it would take the name Bruna, after Adam, the first storm of the season to hit the Iberian Peninsula.