Tour de France Deluge?

Today is a rest day in the Tour de France, but tomorrows Stage 16 takes the riders from Saint-Paul-Trois (red pin) to Gap (purple pin) in the western Alps.

The stage could be wet.  A strong cyclonic potential vorticity anomaly will be swinging across France tomorrow, with rain sweeping into the western Alps during the race.

GFS dynamic tropopause pressure (red contours), surface wind

(grey vectors) and 6-h accumulated precipitation (color filled

every 5 mm after initial .25 mm contour) at 1200 UTC 19 July 2011.

Source: Don Murray/ESRL.

Velonews reports that up to an inch of rain is expected for the finish in Gap, with temperatures in the 50s or low 60s.  The riders are fortunate that this is a relatively low Alpine stage with a maximum altitude of 1268 m in the Col de Manse.

Source: Velonews

The forecast available on the official Tour de France web site calls for "Persistent and heavy rain, locally thundery, in the morning....mostly cloudy during the stage with outbreaks of rain, thundery at times...fog in places, especially in Manse Pass."

Source: letour.fr

This stage was not expected to tilt the balance of the race, but with the competition for the yellow jersey so tight this year, perhaps the weather will provide an opportunity for someone to make a move.