Science

These weather disturbances awaiting the skippers of the Vendée Globe 2020


The Vendée Globe is, to date, the biggest sailing race around the world, solo, non-stop and without assistance, as indicated by the event website. This year, the ninth edition started in ideal weather conditions. However, the competitors will have to deal with several depressions in the days following the start, causing more or less disruption.

An atmospheric depression is a closed area of ​​low atmospheric pressure, compared to that of the neighborhood at the same level. It is often associated with a disturbance and more or less strong wind.

An ideal start before the first difficulties

The 33 participants of this ninth edition of what the general public today calls the Everest of the Seas set off on Sunday, November 8, from Les Sables d’Olonne. The weather was good when they left, with bright sunshine and calm seas. The competing fleet was able to set sail under a moderate wind of 12 to 15 knots, that is to say whose speed is approximately between 24 and 30 km / h (force 4 on the Beaufort scale).

The first night was a little more muscular for the skippers, who had to deal with a front moving from West to East, with more violent gusts at 30 knots, i.e. up to 60 km / h (force 7 on Beaufort scale).

More disturbing disruptions to come

A second low with fairly strong winds should reach the competitors during the day Tuesday. According to West France, a small additional low pressure phenomenon was detected at the front of the road to the south, in the extension of this second front. It is probable that this minimum will come “play the spoilsport”.

The third and last depression forecast will undoubtedly be the most formidable for the skippers. According to the daily article, “Its unstable character, with numerous thunderstorms and associated strong winds, gives it a character liable to degenerate”. This depression is in fact likely to cause a strong disturbance in the Atlantic.

Christelle Robert, forecaster at Météo France, indicated that “the disturbance will be located in the South of the Azores on Wednesday, ”Where it could harm competitors. Indeed, a third of the waves generated, “the deepest”, Can reach heights of up to 6m50. Off La Coruña (Spain), the waves will be on average 3m50 high. It is a thalweg: an axis of low pressure at altitude, generally extending a depression and favoring the instability of the atmosphere and cloud formations.

This disturbance will then evolve rather slowly towards the East, with a fairly strong associated wind around. A low pressure around Ireland could cause rain in the Atlantic, but the Vendée Globe skippers are likely to be far enough away not to be impacted.

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