The above photograph was taken by Jon Milliken in 1999. Cumulus build-up over the Pyrenees, some miles behind the Ager ridge, is common. During September, although the thermals are usually large and mild -- ideal for low-airtime pilots -- thunderstorms often develop in late afternoon.

Ten years previously, in September 1989, the author watched (from the landing field) hang gliders flying above the ridge, specks against a towering cumulus behind. Low rumbles of thunder began to echo. All the hang gliders escaped the cloud suck, though at least two were Hoovered into 'white-out' conditions for a short while. Astonishingly, none of the pilots the author spoke to afterwards heard the thunder.

In the evening there was a downpour in the valley. A group of men, having begun their drive down the mountain too late to avoid the storm, described a sub-zero gale with hailstones the size of golf balls.