Facets.

The cold and generally settled conditions have continued in Lochaber. Normally snowpack stability will improve during settled periods. However, due to the consistant low temperatures of late, a strong temperature gradient has developed within the snowpack. This has caused a process called faceting to occur within certain layers. This process is due to vapour transfer within the snowpack and causes the crystals to become angular in shape, and have a sugary consistancy. These layers are very weak, and in many locations are covered by a layer of windslab.

In the picture a crack shoots out from my feet (a sign of poor stability) on an easy angled slope at the top of the West Face of Aonach Mor. Very weakly bonded areas of windslab were also observed on the East Face. Although no spontaneous avalanches are happening at the moment, there is potential to trigger avalanches on slopes of almost any aspect.

Have a good new year and be careful folks.

Blair

Cold and settled

Conditions have been cold and settled for a few days now. Great for the festive holidays. Here are some pictures from on and around Aonach Mor over the past few days.

Looking over to Carn Mor Dearg and Ben Nevis today.

The crags in Coire an Lochan are pretty buried. I think the routes here would be pretty hard work with a lot of clearing required.

There are a few cornices around as well.

Surface hoar forming in the cold, settled conditions (for scale the larger grid on the crystal card is 3mm). These sparkly little crystals are the cause of many avalanches in the Alps and North America, where they get buried by subsequent snow falls, and become a weak layer/sliding surface. They are less common in Scotland's maritime climate, but now they have formed in some locations they could easily become significant if we get a large snowfall before they are destroyed by either high winds or a thaw.

Very quiet up the Ben today with only 2 parties visible: Point five and Castle Ridge.

Underfoot its still deepish unconsolidated snow

Spot the climber in Point Five today

Happy Christmas

Happy Christmas from snowy Glen Nevis looking up towards Meall Cumhann and the West face of Aonach Beag

A new Season

Is the weather about to clear up.....

Well it has been a wintery start to the avalanche forecasting season. The past few days have been cold, with summit temperatures of around minus five and fresh snow down to sea level. For a short time this morning it looked like it was about to clear up on Aonach Mor, but suddenly the wind got up and it started snowing. At the summit hut I met two climbers who had originally planned to descend Easy Gully into Coire an Lochan. However, with a fair bit of soft windslab about, and the poor visibility, they sensibly decided to head over to the West Face (often a safer bet when there is a substantial avalanche hazard in Coire an Lochan).

Discussing options at the summit hut

Heading away from the top of Coire an Lochan in some wild weather.