It looks as though the weather over the North Atlantic has been severely shaken by the succession of cyclones over the last few weeks.
« From a general point of view, this year has been marked by a great deal of cyclonic activity which looks set to continue through to the end of the season, around mid-November. This situation should not have much influence on the tropical zone through which the Transat Jacques Vabre multihull fleet is to run. However, it may influence the first part of the course – as these cyclones die out, they return to the west of the North Atlantic after having run down the east coast of America during which time they lose quite a lot of their intensity. This mass of hot air meets zones of cold polar air, reinforcing low pressure systems from Québec and becoming increasingly active and picking up speed as they reach Europe.
In parallel, for all the Azores High is in its rightful place, it is not very strong. Last week, the perturbations passed quite far south (around 40°N) before running into the European high pressure systems. The systems moved upwards towards Iceland and so France did not bear the full brunt of them. This is not at all unusual for this time of year. What is unusual this autumn however, is the level of frequency. Furthermore, the type of depression kicked up by the warm air of a cyclone often has a highly complex path. Accurately predicting its track becomes possible to within just two or three days. It is important to note that phenomena of this type affecting the North Atlantic do not appear to be influencing the structure of the African trade winds, nor on the configuration of the Doldrums. »
What is your role as meteorologist and where is Mayeul Riffet's role ashore ?
« For Thierry Duprey du Vorsent and Erwan Le Roux on Gitana X, I shall be working together with Mayeul Riffet ashore. Mayeul will remain at the Gitana Team base in Saint Philibert. He will be acting as strategy consultant whereas I will be in Météo France supplying compilations of analysed weather data. To sum up, Mayeul is the « router » and I'm the « meteorologist ». I draw upon all available models world wide. For the Transat Jacques Vabre course, there are four relevant models, French, European, English and American. All four have to be analysed in order to obtain the model which is the closest to the actual situation. Once we have extracted the information in this way, Mayeul and I are then able to draw up a strategic outline which we then submit to Gitana X.
Depending on what they decide, if several options are available, we will determine the ideal track the trimaran should follow according to her speed polars (theoretical speed taking into account the strength and direction of the wind). Five day models provide good data but also forecasts over a fortnight. Forecasts can be quite accurate over 4 to 5 days, but the longer term view is useful in helping us anticipate a number of possible scenarios.
Five-day models are used to describe lows, highs, pressure fields, wind angles and so on. Beyond that time, we rather describe flows, trends and centres of action.
My role involves preparing a weather synthesis so that the guys on board do not spend hours on the web seeking out information. This saves time for them. When you are sailing two-handed, you've got other stuff to do ! I also provide them with a two-three day view so that they can hone their short-term strategy. My role is to look ahead and anticipate what will be happening 36 – 48 hours later. »
Can you describe a typical day for the team ashore and on the boat ?
« The type of data transmitted on Gitana X involve two of three charts a day which may be satellite images under the tropics, pressure gradient charts, wind fields and the position of the fronts. It all depends on the sailing area. In fact, the value of the data also depends on the weather cover and how precise the information is. Wind field information for the Doldrums for example is not that coherent as the winds are so unstable from one hour to the next. Satellite images give a good idea of the cloud activity and of the related winds however. Grib files exist to enable the guys to run their routing software and optimise their track, but this type of file is better suited to the Channel, the Bay of Biscay and the African trade winds.
I also work on data provided by shipping which gives a much more accurate picture from out in the field along with the information send by Gitana X. Mayeul will have even more information to enable him to draw up a finely-tuned weather strategy which he will send to the boat. Together we realise a synthesis which considerably frees up the guys on board to get on with sailing the boat. Multiplying the sources provides us with incoming information almost all the time. This means that there is no specific time in the day for forwarding the information. We contact the boat when the viability and analysis of the information requires. There is no point creating restrictions for the sailors who have got to concentrate on sailing the boat.
Ashore, fleet positions are provided very four hours. Every hour, or more if necessary, we get the position of Gitana X. If the crew wants to contact us ashore for more information, Mayeul acts as the person they contact so that there is just one single person to liaise with. I'll be in Le Havre four days before the start to go over the information with Thierry and Erwan and to draw up a forecast for the first three days of the race before the starting shot is fired on 6th November. »
In the world of sailing, the name Gitana is synonymous with the French-Swiss branch of the Rothschild, and conjures up a style of living going back more than 100 years, comprised of passion, team spirit and the quest for excellence. Under the aegis of the Baron Benjamin de Rothschild, the story of the Gitana boats turned to multihulls in 2000 when Gitana IX was entered in the Transat Québec /Saint-Malo yacht race. For the second year running, the Baron is active on the ORMA Championship circuit with two trimarans, Gitana X and Gitana 11. Gitana X is devoted to training young talent and Gitana 11 aims to shine at the highest level. Tradition, innovation and transmission…
Photo image bank : Yvan Zedda
Video image bank : Néfertiti Production