What we said earlier today (Wednesday 29 Jan) still holds true for Thursday 30th January. But be wary, Meteo France have reduced the forecast danger rating from 4 to 3 for Thursday, but this is not really a reduction in risk for skiers. The reason they are reducing the rating is that they are not expecting so many spontaneous avalanches like happened today and they expect the avalanches to be smaller than they might have been today. However, this does not reduce the risk that a skier might trigger an avalanche. Thursday will be at least a “very high 3” There will be a widespread risk that a single skier could trigger an avalanche, both being on the slope and/or remotely from a distance.
More snow has fallen and the weak layer can rear its ugly head. Especially on cold and N shady slopes or wind loaded slopes. But also with rapid warming on Thursday and Friday expect instability from the temperature change
Here are a few quotes from experts
Significant avalanche activity today in most of the Savoie mountains. Positive and sometimes surprising results on pida road or track, several accidental avalanches (La Plagne, Corbier …), impressive remote triggering towards Giettaz, 80cm at 2m break over 200m wide (see avalanche data in the evening)Alain Duclos – data-avalanche.org
Today, they opened the Épaule de Charvet. So the Piste Patrol have been confident enough to do that. I think with the continued snowfalls with less violent winds, there will be increased slope instability and more avalanche activity (violent wind tends to have a stabilizing effect while moderate winds tend to be more efficient at loading slopes with unstable snow)… having said that Météo France has put the danger rating down for tomorrow- that may be because they don’t forecast the natural avalanches and size that fits a 4. BUT I believe there is going to be a very high danger of triggering avalanches from tomorrow onward as you point out in the report (also with increased visibility the temptation factor / following tracks is going to exacerbate that danger and risk taking). So for me it is a ‘very high 3 bordering on 4’ for tomorrow and possibly for the days after with the continued snowfalls forecast’Henry Schniewind – Henry’s Avalanche Talk
And last thought to maybe communicate is that there’s a very good chance the skiing is going to be excellent and various points over the next week!Henry Schniewind
Blog post from earlier Wed 29 Jan
The avalanche bulletin for 29th Jan was really quite blunt and simple click here. All aspects of all slopes have a high risk of avalanche due to the volume of fresh snow that has fallen and is still falling, plus there is a weak layer. The professionals are talking about the risk of spontaneous avalanches as well as those triggered by a skier.
On Monday prior to the snowfall Alain Duclos from data-avalanche.org has highlighted to the professional guide community that there is significant evidence of a weak layer just below the top of the snowpack in many places.
This weak layer seems most prevalent on north-facing shady slopes at all altitudes. South facing sun affected slopes or heavily skied off-piste is less susceptible
We also picked up reports of skiers triggering small avalanches right next to the piste in Val d’Isere in the fresh snow yesterday. This was just the fresh snow sliding on top of the snowpack before it had settled. These avalanches had little consequence yesterday. However, today the danger is much greater as the quantity of snow is much higher. 40cm ++ and a lot more where it is wind loaded and the snow is still falling.
What does this mean for skiing today and beyond?
Stay away from and off any avalanche terrain. Keep a big distance between you and any slopes that are steeper than 30 degrees. This applies until it is clear the snowpack has stabilised. Remember it is not just the slope angle under your feet that matters. It is the slopes above you as well. Keep on the marked pistes and on low angle slopes if you go off piste. The same risk applies in the trees, stay on low angle slopes.
When the weather clears and the snow settles down, remember this weak layer exists just below the top of the snowpack (as of Monday this week). This will make judging safe terrain quite difficult. North facing wind loaded slopes will be the riskiest. Heavily skied off piste will be less risky. But …
Remember to read the bulletin every day
Look for evidence of recent avalanche activity
Apply the HAT risk framework and decision tool click here