Saturday is set to be the warmest day of the week with temperatures reaching 26°C, but there is a risk of storms and competitors in the race will be keeping a close watch on the weather forecasts. “Storm cells are likely to develop to the east of Le Mans. This will be a short-lived phenomenon, but there is a risk between 15:00 and 20:00,” explains Pierre-Yves Guillerm, forecaster for Météo France Sports, the Météo France unit that works on all national and international sports events. “The most difficult thing is pinpointing where and when the storms will break and the trajectory that they will follow.” There is also a small chance of showers between 08:00 and 14:00 on Sunday. Such changeable weather could well add to the suspense during the race! Teams will need to interpret the forecasts and adapt their strategy accordingly. “We often see differences in strategy. Some teams have their own weather experts for extra input,” the forecaster continues.

POWERFUL OBSERVATION TOOLS

During Race Week, competitors and Race Control benefit from increasingly accurate forecasts from Météo France Sports’ systems, which include radar to monitor rainfall near the Circuit. “We also have a dedicated weather station that measures ‘usual’ weather parameters such as air temperature, the occurrence and intensity of rainfall, atmospheric pressure and wind direction and speed. We measure track temperature too because that’s a highly important parameter for racing teams and their tyre choices.” This weather station is positioned after the Pit Straight by the Dunlop Curve.

Yet forecasting the weather over a 13.626-kilometre circuit can be tricky business! Sometimes, it can be raining at Arnage while the sun is shining over the Pit Straight. The Météo France Sports forecasters use powerful observation software to anticipate this kind of thing.
The 24 Hours of Le Mans is a formidable testing ground for automotive technology and likewise, Météo France continuously strives to improve its forecasting systems. “As we develop increasingly refined meteorological models, we will be able to better anticipate very local phenomena such as storms. We can further improve our rainfall tracking systems for ever better short-term forecasts in the years to come,” adds Pierre-Yves Guilerm.