White mess

It happens once every 15 to 20 years. And when it does, it is chaos in Provence. It doesn't take much: 20 to 25 centimetres of snow, a temperature a couple of degrees below 0 °C and in less than an hour, traffic comes to a standstill, hundreds of motorists find themselves trapped in their cars, trains stop on their tracks and the weaker parts of the power grid shut down.

This is what happened last Wednesday, as it did in December 1973 and in January 1987. "It was just a basic conflict between a cold stream descending from Scandinavia and warm, stationary air above the Mediterranean," says Bertrand Laviec, from Météo-France Regional Centre in Aix. "Snowfalls were heavy, but no historical record has been broken. This type of event was quite frequent and even more spectacular in the 1950s and 1960s."

So why, to quote some of the headlines in the local newspapers, the "Chaos," the "White Mess," the "Panic," and the "Fiasco"? In normal conditions, traffic on the motorways leading in and out of Marseille is exceptionally dense, with more than 50,000 people commuting daily between Aix and the region's metropolis. On Wednesday, snow started falling when truck drivers were leaving the autoroutes' rest areas and commuters were starting their drive to work. The result was a monster gridlock that shouldn't have come as a surprise. Despite all efforts from municipal services, motorway authorities, fire brigades and police forces, it took more than 24 hours to bring the situation back to, almost, normal.