Cornices and debris
20th January 2023
The avalanche hazard has been Considerable in Lochaber for the last week but the summits have mostly been in the cloud which makes evidence of avalanches hard to see. Today was a lovely cold, clear day and as expected there was quite a lot of avalanche debris about. Most of this was from avalanches that happened last weekend or at the beginning of the week and this debris was covered by fresh snow on Wednesday and Thursday (but still visible). There was also some debris from avalanches which happened on Thursday and Friday due to weaknesses in the fresh windslab. Most of these avalanches were triggered by cornice collapse and as the photos below show there are still plenty of large, fragile cornices waiting to collapse.
It has been a windy week with fresh and drifting snow. The cornice collapse this week was triggered by the cornices growing until their own increased weight and amount of overhang caused them to collapse. Tomorrow the forecast is for a rapid rise in temperature and some rain and this will trigger further cornice collapse with this then likely to trigger avalanches.
Cornices above Coire an Lochan.
Many of these cornices will collapse as the temperature rises over the next few days. This may well trigger avalanches on the slopes below.
Triple cornices
Crown walls at the top of Easy Gully, Aonach Mor. Avalanche probabaly triggered by cornice collapse.
Slab avalanche in Coire Dubh probably happened yesterday.
Ben Nevis and Carn Mor Dearg from the South. Thanks to the SAIS Glencoe forecaster for the photo.
Carn Mor Dearg and Ben Nevis from the North this morning.
Carn Mor Dearg with Ben Nevis behind.
Some nice skiing conditions today.
A probe is useful for feeling the layers in the snowpack. My 3 metre probe didn’t reach the ground at the top of Summit Gully, Aonach Mor.
Clear conditions today. The distant ridge is the Skye Cuillin.
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Judith Hill
21st January 2023 1:14 pm
Many thanks for your work. What fabulous, useful, detailed photographs.
Regards & stay safe !