Brilliant start to the season, but early season snowpack is unstable

Off piste snow depths 28th November 2019

You have no doubt seen that there has been considerable snowfall across the French Alps through November and this has created a great but unstable base for the season. There have been four different snowfalls so far and two of them have been Retour d’Est events in the past week and this has dumped over 1m of snow on the Italian border. You will find better snow and greater risks in the Maurienne, Fornet, Val d’Isere, Tignes, St Foy, La Rosiere. You will find spectacular snow in all Italian resorts.

These pictures from the Piste Patrol in Val d’Isere show just how good it is looking there.

It is snowing hard today (Thursday). See this video from the Piste Patrol.

The snow is forecast to continue on Friday and then die out in the afternoon. This will be followed by a beautiful, blue sky powder day on Saturday. So the resort openings in Val d’Isere, Tignes and Les Deux Alpes will all be spectacularly good.

There will be more snow on Sunday. This will come from the NW and will provide a welcome boost for all those resorts away from the Italian border. Places like Val Thorens, La Plagne, Flaine and the Portes du Soleil will get more snow than Val d’Isere and Tignes.

We are expecting the weather settle down next week and get much colder for a few days. Then sometime around the 7th or 8th December expect some more snow coming in from the west, but this could be confined to places above 2000m.

It is a great start to the season, but experience shows that a snowy November can be followed by stable weather and a snow drought from mid-December to early January. The snow base looks fantastic, we need some sustained extra falls of snow to build it up. Either way, there will be good skiing available for the Christmas and New Year holidays.

What is the current avalanche risk in the Northern French Alps/Savoie?

We would expect the danger rating to go up on Friday and Saturday due to the fresh snow falling on an uncertain and possibly unstable base. There is not an official forecast for the rating yet. The early season avalanche bulletins are light on detail and not comprehensive. The forecasts will start in mid-December. However, on Thursday the resort of Tignes is declaring considerable risk at 3 /5 and Val Thorens is declaring moderate risk at 2 /5. Expect this to increase on Friday and Saturday.

This difference between these resorts reflects the two recent snowfalls which came from a Retour d’Est and came over the Italian border. Resorts closer to the Italian border have received much more snow than places further West or North.

We have had at least four difference snowfalls. Early snowpits and snow profile testing showed different layers with some rounds (stable) snow and some facets (unstable) snow layers. The warmer weather earlier this week has stabilised this below 2300m. But anywhere higher or that has stayed cold has an unstable layer at the base of the snowpack and the new snow is sitting on top of this

What does this mean for off-piste skiers and snowboarders?

Look for recent avalanche activity. Ask the Piste Patrol for advice. Early season snow is very unstable and it is hard to interpret these conditions at this point.

To stay safe stick to low angle slopes and avoid large wind slabs

Where is most at risk at the moment?

The greatest risk is in high (>2400m) areas close to the Italian border, so Fornet, St Foy, La Rosiere, all Italian resorts, Cervinia and Zermatt

As always in the early season. The greatest risk is on high north-facing slopes with new snow or wind loaded. However, it is not just north-facing slopes that are unstable.

Areas often become safer through the season as they are skied many times and skier compaction stabilises the base. This effect has not had time to occur as yet. So popular places that are often become safer through the season, but are not safe at the start of the season

What is the likely avalanche activity this week?

The snowpack is unstable and a skier going on to or close to a wind-loaded slope or a slope with new snow that is steeper than 30 degrees is likely to trigger an avalanche. Look at the results of the avalanche blasting. This will show you if the slopes are stable or unstable.

How does the forecast look for the coming week?

Snowfall and cloudy until the weekend (temporary calm Saturday). Calmer and cold next week.

Night from Thursday to Friday
More snowfall in the mountains from 1300/1400 m, 5 cm to 1800 m, 10/15 cm to 2500 m. Temperatures minimum: 6/8 DG in plains, 0 / -1 DG towards 1500 m.

Gray sky, covered summits.
Tarentaise: frequent snowfall and showers, the limit of rain / snow 1500 then 1300 m in the afternoon. Quantities: 10 cm to 1800 m, 20/30 cm to 2500 m. Risks of avalanches in the mountain (cumulative from Wednesday to Friday 50/80 cm towards 2500 m, in particular on Beaufortain, Vanoise, Tarentaise).
Haute-Maurienne: little precipitation, showers in the middle of the day, strong wind and many clouds stuck to the terrain, stealthy gaps possible. Lulls everywhere during the night from Friday to Saturday.
Maximum temperatures: 9 DG at Albertville, 4 at Modane, -3 at 2000 m, -9 at 3000 m.

Isotherm 0 DG: 1800 then 1600 m.
Isotherm -10 DG: 3300 then 3000 m.
Wind at 2000 m: W 20/40 km / h.
Wind at 3000 m: W 50/60 km / h (Haute-Maurienne 80 km / h).

sun and warmer
Nice day calm and sunny. Becoming veiled in the afternoon. Beware of the risk of avalanches in the mountains (consult the Snow and Avalanche Information updated daily on the app and the website of Météo-France, heading Mountain).
Maximum temperatures: 9/12 DG in plains, +3 to 2000 m, -6 to 3000 m.

Isotherm 0 DG: 1700 up to 2600 m.
Isotherm -10 DG: 3400 up to 4100 m.
Wind at 2000 m: calm then SW 20 km / h.
Wind at 3000 m: NW 20 then SW 20/30 km / h.

wet, fresh, snow in the mountains
Gray covered summits. Rain in the plains, frequent snowfall above 2000 then 1500 m. Quantities: 30 cm on Bauges, Beaufortain, Vanoise, Basse-Maurienne. 10 cm on Tarentaise and Haute-Maurienne (low Lombarde).
Maximum temperatures: 6/9 DG in the plains, -2 to 2000 m.
Isotherm 0 DG: 2400 then 1800 m.
Wind at 2000 m: S 15/30 km / h.
Wind at 3000 m: S 60 km / h.

Monday 2: cloudy and cold, sometimes some flakes into the valleys (very small quantities). Mostly cloudy. N / NE wind at altitude. Isotherm 0 DG to 900 m.
Tuesday 3: cold with generalized frosts. Grey in the valleys, variable in the mountain, dominant sun and rare cloudy passages. wind from E.

Wednesday 4th: some morning greyness in the lower valleys. Good dry and cool weather, high clouds in the afternoon. A gradual degradation on Haute-Maurienne: clouds and rare snow showers from Italy.
Thursday 5: rather calm, cloudy and cloudy, sometimes a shower on the borders.

Friday 6th and Saturday 7th: the arrival of new disturbances by W. Showers, weak snow in the massifs above 2000 then 1500 m, to be specified.

Tip of the week

Ask the local Piste patrol.

The bulletins are a bit vague at this point in the season, so you need to get local knowledge about what is happening. For example, Val d’Isere Pisteurs just published this image on their Facebook page showing that slopes are releasing when they do blasting and they have observed many avalanche releases in the area. So there is evidence of recent avalanche activity and a considerable risk

PIDA triggered avalanche Pisaillas area Val d’Isere