Crowd on Pavey Ark summitWhile the recent weather may have brought misery to thousands of would-be air travellers, stay-at-home mountaineers have had the bonus of some spectacular temperature inversions to wonder at.

grough reader Bob Schofield sent this picture of a crowded Pavey Ark in Great Langdale in the Lake District, taken yesterday afternoon.

Normally, air temperature lowers by about 3 degrees Celsius for every 300m ascended – the lapse rate – hence the familiar chill on mountain tops. However, when you have a mass of high-pressure air descending, as we have had recently, this traps the cold, moisture-ridden air low down and stops it rising.

So we get the phenomenon of low cloud and fog – and crippled airports – while the fell and mountain tops bask in glorious sunshine above, in the warm descending air.

So make the most of it; get those boots on and climb a mountain. And if you see a grey-bearded old man with a heavily laden sleigh flying above the mist, give him a wave.