Temperature inversion.

A slightly harder frost last night and another blue sky day drew a few more ice climbers to Ben Nevis today. However it was not quite as good as yesterday due to the temperature inversion being more pronounced. Over night, cold air sinks to the glens and warm air rises to the summit so that the usual temperature gradient (warm at the bottom, cold on top) is inverted (cold at the bottom, warm on top). With such calm weather there is no wind to mix the cold and warm air so it is possible that the effect will get stronger day by day this week.

Unfortunately this meant there was significant amounts of falling ice on the faces as well as some water running down the gullies. Mick and I decided early on not to continue up Orion Direct to climb Astral Highway but Steve and Rob did manage to climb Zero Gully along with another team. There was some mushy ice and soft snow on the route as well as plenty of debris falling down. Hadrian's Wall Direct was climbed as well as Point Five Gully but the message is to start super early and even then it might be quite as good as it looks in the pictures!