This Monday, between an anticyclone at 1030 hPa positioned in the north of Ireland and a low pressure at 1017 hPa over central Europe, sustained flow from the north-eastern sector over north Biscay weakening as it approached the Iroise Sea before to strengthen in the northeast towards the English Channel. Tuesday, weakly disturbed north-easterly regime in the English Channel, generated by the 1035 hPa high pressure north of Ireland and a relative low centered in northern Denmark. On Wednesday, weakly disturbed north-easterly regime generated by the 1035 hPa high pressure still centered in the north of Ireland.
Since the start on Sunday at 2 p.m. from Lorient, the fleet has benefited from good general conditions to progress for the most part at high speed. If the first hours took place under an unstable wind as far as Belle-Ile, the flow then gradually organized to the northeast. It even strengthened significantly in the evening up to 20 knots, to allow the first to pass the Rochebonne mark around 1 am last night at an average of 11 knots. The gaps were then small with the latter but quickly increased. Indeed, if the ascent last night towards the Iroise Sea averaged almost 14 knots for a good part of the boats, the last ones only progressed at 10 knots. As a result, there is already a gap of more than 30 miles with the first who approach the Iroise Sea at the start of the day in a northerly wind of 20 knots.
Taking advantage of a north-easterly wind of around 20 knots for a few more hours, most of the competitors will continue to progress at high speed until they approach the Iroise Sea. Under these speed conditions, the gaps will widen further with the latter.
These general conditions will nevertheless evolve, as planned for a few days. The formation of a thermal depression south of the Iroise Sea this afternoon will cause a temporary and fairly localized drop in the wind to 6 knots. The competitors will have to bypass it to the west, to avoid this trap, and then be able to recover a flow from north-northeast to northeast. This situation could penalize latecomers, as this area of light winds is expected to expand by mid-afternoon. It will also be necessary to manage the contrary currents which will reach up to 0.5 knots.
The fleet will then begin its ascent of the Iroise Sea upwind, in a very unstable moderate flow of 8 to 15 knots varying between the north-northeast and the northeast. In the evening, the wind will strengthen again to nearly 20 knots north of the Iroise Sea, in light seas and head on with waves of 1 m.
The persistence of the high pressure at 1035 hPa in the north of Ireland will maintain a moderate and sometimes quite strong flow in the ascent in the West Channel. Upwind, and in a sustained wind between 17 and 22 knots, the skippers will have to refine their strategy and tactics by choosing to stay on the direct route with many turns or to try sometimes more radical options by heading north to keep speed. The instability of the wind and the fatigue accumulated over the past 24 hours will be determining factors which will limit the performance of some. Sky side, the weather will change with a mostly cloudy sky, a few showers and coolness … A feeling very different from the sun from the start.
The centers of action will not change too much and the fleet will continue to progress towards the arrival at Fécamp in a sustained north-easterly flow between 17 and 22 knots and fairly rough seas. This should lead them to cross the finish line around midday for the first ones.
For more information, visit the website: https://figaronautisme.meteoconsult.fr/
Pascal Scaviner, METEOCONSULT
–
