On Sunday, around 200 cyclists had to be rescued from the Col du Galibier while on a "Brevet alpin de cyclotourisme." Dressed for summer conditions, they bore the brunt of 3°C temperatures before reaching the top of the pass, which was covered by snow. Cyclingnews understands new falls of 15 to 20cm of snow over 2,500m are expected Tuesday in Galibier, which peaks at 2,645m.
It could be that the Tour de France faces a serious problem as it will climb these roads twice, Thursday to a mountaintop-finish and Friday on the route to Alpe d'Huez.
The race might avoid the snow, however.
"The Tour is pretty lucky," forecaster Yan Giezendanner told Cyclingnews. "Imagine if the snow would fall Thursday and Friday instead of Tuesday and last Sunday: the road would certainly be blocked."
A Météo-France meteorological expert, specializing in mountain climates, Giezendanner says the "sun will melt the snow" before the stage on Thursday. "There might be only some ‘névé' on the climb but nothing that will adversely affect the race," he adds, referring to the patches of residual snow which have been partially melted, refrozen and compacted.
Thanks to the warmth of the sun, the temperature at the top of Galibier might be sustainable for the riders, both Thursday and Friday.
In the same area, Tour de France organisers in 1996 were been forced to cancel the main part of stage 9 from Le Monêtier-les-Bains to Sestriere, because of the iced rain in the Col d'Iseran and the 100km/h wind in Galibier. The stage was reduced from 189 to 46 kilometers and only held on the Montgenevre and Sestriere climbs. Bjarne Riis took the yellow jersey that day, taking the first steps of his overall victory.
Mountains are well-known for their capricious weather in summer. "I remember 20cm of snow fell on La Plagne resort 1989 the first of August and hail storms in the Galibier the 2nd of July last year," recalled Laurent Cadars, the manager of the Valloire Council which encapsulates the Galibier climb.
Forecaster Giezendanner confirmed this year's snowfalls are indeed seasonal.
He predicts rain on stage 16 to Gap, Tuesday. "Rainfalls will go with the race almost the whole day. Sunny periods will be rare. The race the bad weather will both head north."
Stage 17 to Pinerolo will be quite warm, with a 30°C temperature expected at the finish.
Thursday, the finish to the top of Galibier will be sunny too and the riders will have a tailwind during the stage. The temperature at the finish is estimated to be about 6°C.
It'll be a bit warmer Friday for the second Galibier ascent, en route to Alpe d'Huez, with 7 to 8°C at the summit of mythical pass and 12 to 13°C at the finish.
"Of course the temperature is differently appreciated with the sun," Giezendanner said. "6°C temperatures are really sustainable if the sky is clear but you'll be frozen if you are in the shade. Fortunately the next days at the Tour won't be cloudy too much."