Hundreds of trees falling in just a few days – a rare phenomenon in autumn worries experts

With Storm Ciaran arriving, many more trees could fall or even be uprooted This week in France than during previous storms. Here's why.

Gusts of up to 140 km/h on the coasts and at high speeds. 110 km/h inland. Only a few days after Céline's depression which swept away her life. the Atlantic side of the country, the north-west of France is preparing for the coming year. to be whipped again by the violent winds of Storm Ciaran.

The "quite exceptional" is considered as a "dangerous phenomenon" by Météo France which is already refining its forecasts. And for good reason: if violent winds blow at more than 100 km/h are already dangerous as such, they can cause significant damage. Near the coasts, they agitate the swell, favoring the formation of waves and therefore the risk of submersion, while inland, they threaten to bring down trees.

The risk of seeing the trees blown away by the gusts of Storm Ciaran, expected between Wednesday and Thursday, is increased tenfold, because with a summer-like start to autumn, the trees are still leafy at the start of November. A phenomenon far from being trivial, which worries experts. Branches laden with leaves offer better wind protection than a tree that is already covered with leaves. naked for the winter. And by blowing 110-120 km/h on average, according to initial forecasts, the gusts could lead to the fall of many trees. "The slightest gust of wind, with the impact that [it] will have on the leaves, could topple a whole pile of trees," confirmed meteorologist Pierre Huat , at the microphone of France 2.

Even the rooting of trees may not be enough to prevent this. keep certain hardwood trees from falling. The fault of the heavy and numerous precipitations of the last few days: by flooding the soil with water, the rains have made the earth more loose and therefore less capable of retaining the roots of the trees underground in the event of violent winds . Hundreds or even thousands of trees are expected to be destroyed this week.

Not all trees will fall, but there may be significantly more tree falls than during previous severe weather. For every tree that falls, particularly in urbanized areas, there is a risk of infrastructure being crushed under the weight of the giant and its branches. A risk that is all the greater if these buildings, whether houses, public establishments or simply bus shelters, house people. The risk also exists in less urban areas, such as on roads bordered by forests where an uprooted tree in a violent blow can fall on the road and lead to accidents.

In 2023 alone, previous storms have shown  that the risk of being injured by the fall of a tree, although it is not the most important, is very real and can have serious consequences. In August 2023, a 10-year-old child found himself in a car. between life and death after having been hit by a fallen tree in the lee of storm Patricia in Charente-Maritime. In March 2023, two men died in the Vosges and Alsace after falling trees caused by storm Mathis. And again last weekend, several trees were destroyed. Uprooted by the winds of storm Céline, these ones Fortunately, there were no casualties.