Happy new year everyone! Temperatures across the N French Alps this week are set to remain mild for this time of season, with no really significant snowfall expected. Higher resorts like Val Thorens and Tignes still have some wintry conditions above 2500 m or so. However, even at these higher altitudes, which are lucky enough to still have fairly good snow coverage, mild temperatures are affecting the quality of the off-piste snow.
Here’s the Meteo France image of off-piste snow depths for the Haute Tarentaise on 31st December.
Lower and mid-altitude resorts are really starting to feel the brunt of the unusually warm temperatures, and recent rainfall, which destroyed a lot of the snow.
Not the easiest off-piste snow, but making the most of it! Wayne Watson photo
Milder temperatures, along with rain and wind, have spoiled the quality of off-piste snow. Even above 2600 m, the snow has now become very humid. It’s definitely not the easiest to ski, being heavy and often with a surface crust. Anywhere below 1600/1800 m, natural ungroomed snow coverage is very patchy, or non-existant.
All resorts are doing their best to keep their pistes in reasonable condition, and there’s still extensive piste skiing to be found in higher ones like Tignes, Val d’Isere, etc.
In our last few snow reports, we’ve been warning about the danger of skiers triggering slab avalanches due to a persistent weak layer in the snowpack. This danger has been particularly acute on shaded cold slopes at high altitude which have not been helped by the stabilising effect of the higher temps, rain and subsequent settling and/or refreezing.
This massive accidental avalanche in the photo below happened last week on a windward west-facing slope, just after a snow storm with westerly winds. It’s a good example of an exception to the ‘leeward slopes are the most unstable’ rule. All the serious avalanche accidents this season have, to our knowledge, involved cold, dry (or relatively dry) slab avalanches despite the recent abnormally high temperatures. See full report (in French) on the excellent and informative Data-Avalanche website here: http://www.data-avalanche.org/avalanche/1672074412695
Photo © Raphael-MARZETTO. From Data-Avalanche website Skier-triggered avalanche in the Pays Desert area above Le Fornet, Val d’Isere
It was a cold dry slab avalanche triggered by skiers (as are the vast majority of all serious avalanche accidents). The avalanche occurred around 11.30 am, just above approx 3,000 m after a storm with mostly westerly winds and rain to approx 2400 m. Fortunately, due to quick reactions from other skiers in the area, the victims were recovered quickly, and no one died, but serious injuries were inflicted. The recent warming and rain had no influence on the triggering and release of this avalanche.
Indeed, to our knowledge, the relatively high temperatures over the last ten days or so didn’t influence any of the other serious accidental avalanches in the region either, despite media comments to the contrary. Serious accidental avalanches, where higher temperatures are the primary cause, are an exceptional occurrence, according to historical data.
Avalanche Bulletin 1st January 2023
Current danger rating in Tarentaise
The bulletin reports a danger rating of 2 above 2500m particularly on North’ish facing slopes. It talks about there being a few areas of windslab snow which have formed over the last few days on higher N facing slopes above 2500 m, where there’s still some colder snow that has not been stabilised by the rain and subsequent refreeezing. The load of a skier passing by could be enough set off a slide.
Weather forecast 1st to 7th January
SUNDAY, 1st January: Mild and sunny in the mountains. 0° C at around 3000 m, and getting up to 6° C at 2000 m. Thin high cloud will thicken as the day goes on. SW wind, gusting up to 60 km/hr.
MONDAY, 2nd January: Another mild day in the mountains with the sun veiled by thin cloud (just the sort of weather in our featured image, taken by Wayne Watson). SW wind, 40-60 km/hr in high exposed areas. A slight change overnight, possibly bringing a few snowflakes above 1800 m (but not amounting to much).
TUESDAY, 3rd January: Any residual overnight snowflakes will soon die out, and it will brighten up in the mountains. Remaining mild for the time of season.
WEDNESDAY 4th to FRIDAY 6th: Sunny and dry in the mountains, very light breeze and temperatures remaining above normal. 0° C at 2000 m.
SATURDAY 7th onwards: Hoping for a change. Clouding over. Possible light snowfall on Sunday and Monday. Rain/snow limit between 1200 & 2000 m. Fingers crossed.
Tip of the Week
Focus on Facts and Evidence (less on things like wind and temperatures – measurements that have impact, but often contradictory like the avalanche example above that happened on a windward slope) before deciding to go into areas with steep slopes of more than 30 degrees i.e. ‘avalanche terrain’. Of course, we’re not saying don’t pay attention to temperatures, wind etc., but prioritise concrete facts, “what the avalanches are doing” (to paraphrase top avalanche experts LaChappelle and Tremper) when making decisions.
By facts, we mean things like recent slab avalanche activity. Check out updates in the avalanche bulletins, which come out every evening, on websites like data-avalanche and on your own observations with credible others, like piste patrollers and other pros.
Our accident reduction framework is a great reminder of the points that will have an impact on accident prevention.
“Safety is Freedom!”