Another few days of sunshine and above-average temperatures, then snowfall for the end of the week in the N French Alps & surrounding areas. Once we get 20-30 cm, it will be great, but it will also cause acute instability on steep N’ish facing slopes (West to East through North) above 2200 m or so.

Off-piste snow depths above 2000 m are still very reasonable for the time of season. You can currently ski down to around 1600 on S facing slopes off-piste. Some of the lower and mid-altitude resorts are really starting to suffer with their snow coverage. Snowfall expected next weekend will help a lot. Here’s hoping the temperatures go down far enough!

It must be said that current off-piste conditions are not particularly easy. They mainly consist of compacted snow, often icy first thing, but with the surface softening up as the day goes on. There are occasionally ‘spring snow’ type conditions on some of the lower altitudes and steep E and S facing slopes by about lunchtime. Some nice grippy ‘chalky’ conditions can be found on some of the steeper N & NE facing slopes. There remains a serious risk of going for a long slide, if you lose control (see last week’s snow report for a video and overview).

With snowfall expected from Friday and particularly on Saturday (possibly in large quantities) this will all be completely changing as we go from spring-like conditions back to winter.

Avalanche Bulletin

The current avalanche danger level is between 1 and 2 / 5 above 2000 m, and 1 / 5 at lower altitudes. This difference is due to the warmer slopes below 2000 m becoming more stable as they melt and refreeze. In fact these lower slopes, and even most of the higher ones are very solid and stable at the moment.

However… when, any significant fresh snow falls (as is forecast at the end of the week – see weather forecast lower down) steep North’ish facing slopes (mainly from East to North to West facing slopes) above 2200m (and any other high slopes that don’t get much direct sun) will become very unstable and very sensitive to triggering (by people).  This is due to the old unconsolidated snow we currently find in these places. This ‘future weak layer’ that has formed from the very low snow surface temperatures that are still occuring during clear/partially clear nights and also during the days in shaded places. For more details and info on the processes that lead to this situation, see last week’s snow report on this link.

Also see this ‘Propagation Saw Test (PST)’ by Alain Duclos of Data Avalanche from late last week. It’s an excellent demonstration of the very unstable nature of a persistent weak layer forming in the snowpack on slopes mentioned above – and how these types of snow layers are setting things up to be very unstable once the weight of new snow is on top of it.

On the contrary, slopes that have been subjected to consistent above-freezing temps and the sun’s rays – especially those slopes exposed to the sun (South’ish facing) have formed an exceptionally solid base, thanks in large part to melting and freezing. These slopes will, in general, be much more stable.

Numerous 'glide cracks' (sometimes known as 'brown frowns') can be observed at the moment. These in Wayne Watson's photo were spotted in Tignes on 3 Feb 2024

Along with these brown frown shaped glide cracks that we’re seeing such a lot of at the moment (as in Wayne’s photo), there will be the usual, predictable danger of natural wet/humid snow avalanches. (See my article on glide cracks  – they’re a really interesting phenomenon and look a lot more alarming than they really are!).
Natural wet/humid snow avalanches are the most common type of avalanche in terms of visibility, audibility and often in quantity (whether originating from a glide crack or not). However, they’re only involved in a very small percentage of avalanche accidents. This is because of the predictability (cause-and-effect nature) of the phenomenon.
When slopes are exposed to higher temperatures and plenty of sun’s rays, they become unstable. Then, once refrozen, they become very stable (see my article on wet snow avalanches).

The vast majority of avalanche accidents involve cold, dry slab avalanches. They are almost always triggered by the victim (or someone in their group) on North’ish facing slopes (in the Northern Hemisphere) in December, January and February.

When fresh snowfall arrives at the end of the week, these high North’ish facing slopes are where the danger/sensitivity to triggers will be most prevalant. 

Weather forecast : Sun 4th to Fri 9th Feb

SUN 4th: Remaining spring-like conditions. A sunny day in the mountains with temperatures much higher than normal for the time of season. 0°C at 2800 m and even up to 3200 m at the warmest part of the day. Light to moderate N  wind.

MON 5th: Continuing the same.

TUES 6th:  Another sunny day, but maybe with some thin high altitude cloud, particularly in the afternoon. 0° C at around 2800 m.

WED 7th: Clouds building towards the end of the afternoon.

THURS 8th & FRI 9th: Conditions beginning to change. Cloudy spells and not quite as mild at high altitude. Possible light precipitation.

SAT 10th: A considerable amount of snow expected down to mid-altitudes (1400 m or so).

FOLLOWING FEW DAYS: Return of winter and snowfall in the mountains, especially at higher altitudes.

 

Tip of the Week

1. To help you keep things acceptably safe off-piste and ski touring, I’m currently working on a pre-recorded online ‘Essentials Talk’.

Here’s a sneak- peek draft: a ‘staff talk version’ of the Essential Talk, featuring an accident Prevention Framework, which I’m making available free of charge for a couple of weeks on my YouTube channel. If  you find it useful, please subscribe to this channel. There are lots of other cool vids in there too! Thanks again to Jérôme for the cover photo.

2. ‘Pocket Memory Aid Pack’ (for help applying the key safety points in the Essentials Talk Framework).
Education and training is not enough.
So we need simplified ‘tools’ or aids to help you remember and apply the key safety points.
It’s set up to help you keep things acceptably safe and includes a scorecard with a scale to help give you with a base reference of how safe/or not, things are.
It’s a small investment to help to keep you to understand and reduce risk and is a much appreciated contribution to our ‘Safety is Freedom’ cause!

Safety is Freedom!