On wet roads, Alberto Contador laid down a surprise attack on the final climb of the day, with Cadel Evans and Samuel Sanchez following in pursuit while the Schleck brothers and Thomas Voeckler fell behind. On the subsequent descent to the finish, superb bike handling by Evans, a former professional mountain biker, enabled him to open up a small gap on Contador and Sanchez. The gap was probably 10 seconds at one point, but closed to 3 seconds as the road flattened and Contador and Sanchez were able to team together to make up ground before the finish.
Frank and Andy Schleck lost more substantial ground, with Andy criticizing the descent as dangerous. Such is bike racing and those who made up ground today took advantage of an opportunity, got out in front to avoid crashes, and utilized their bike handling skills to their benefit on the descent.
The image below shows the upper-level cyclonic potential vorticity anomaly and comma cloud that impacted the race today.
Looking at the GFS forecast, we may be dealing with cool, unsettled weather for the next couple of days, including Thursday's stage when the riders go over three major passes, including the Col Agnel at 2744 m (9000 ft) and a finish at Galibier Serre-Chevalier at 2645 m (8675 ft), the highest finish ever in the tour.
In case you are wondering, the vertical from Revello to Col Agnel is almost 2500m/8000ft!