Perfect snow conditions. Snowpack slowly settling, some slabs can be triggered on NE, N, NW slopes especially under the ridges near Italian border. More snow on the way
The season kicked off in style with powder snow and high avalanche danger rating 4/5 in resorts near the French/Italian border. Unfortunately two Italian guides were killed in an avalanche around Mont Blanc. Away from the border in Val Thorens the danger rating was considerable at 3/5.
Early reports at the weekend suggested the off piste was variable in quality with some outstanding pitches and others where wind and crust damaged the snow.
We wrote that this was an unstable snowpack near the border. Since then all serious slab avalanche activity has been on the Italian border or further south in the French alps with avalanches triggered by blasting in the Maurienne Valley area and by a skier in Les Sallanches and more blasting in Serre Chevalier. Plus a damaged ski lift.
There was more snow on Sunday and the weather warmed up on Monday and Tuesday and this led to some spontaneous wet snow slides due to warming on south facing slopes.
On N ish facing slopes the new snow improved conditions and current reports are exceptional with cold dry sunny weather improving the snowpack and the ambience. This snow is slowly settling and stabilising. So the risk is confined to fewer places on all NW N and NE slopes in shady spots especially under ridges where the wind blew the snow from the E and S onto the N and W slopes. If a slab does release expect it to be medium to large and possibly 50cm or thicker. So could be really quite serious. This is why the danger rating is still considerable 3/5, the risk is in fewer places but quite serious if it goes.
The weather will stay nice until Sunday with more snow expected Sunday night Monday and maybe Tuesday. Then more nice sunny weather until the 16th 17th December when heavy snow is forecast. Less wind, so the snow quality will be good
There are variable reports on the stability of the snow layers. But there does not seem to be a widespread weak layer yet. This weeks cold dry weather might change that. We will need to read the bulletins to keep up to date.
So look out for slabs on N facing shady slopes and read the avalanche bulletins.
What is the current avalanche risk in the Northern French Alps/Savoie?
It is considerable 3/5 This danger is mostly on NW N and NE facing shady slopes above >2000m Especially under ridges where snow was blown by wind from the S and E to the N and W facing slopes. Look out for wind slab
What does this mean for off-piste skiers and snowboarders?
Look for recent avalanche activity. Especially when the new snow falls next week. Ask the Piste Patrol for advice. Early season snow is very unstable and it is hard to interpret these conditions at this point.
To be sure you can stay safe stick to low angle slopes and avoid wind loaded slopes (where the snow has drifted in and built up. These are generally on leeward slopes but not always. Wind loaded slopes are where there is a higher chance of triggering a wind slab (but tempting to ski on because there’s more snow!).
Where is most at risk at the moment?
The greatest risk is in high (>2000m) areas close to the French/ Italian border, so Fornet, St Foy, La Rosiere, Maurienne Valley, all Italian resorts, southern resorts such as Serre Chevalier and Les Deux Alpes, Cervinia and Zermatt
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 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 a slab that is steeper than 30 degrees will probably trigger an avalanche.
The definition 3/5 means avalanches will Probably be triggered by one skier on a loaded slope.
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?
FRIDAY, DECEMBER 6
, a little colder in the afternoon
After 15h, very high clouds spread over the Pre alps then to the Italian border early in the night, and become denser.
Then at the beginning of the night, the cloudy periods are gradually lower and thicker.
cloud cover spreads over the whole of Savoy by lowering and clinging to the high massifs; at the end of the night is below 3000-3500 m; it gives locally some flakes especially in the mountains.
Isotherm 0 ° C: 2300 then 2200 m during the day, then 2000 m at the end of the night.
Isotherm -10 ° C: 4100 then 4000 m.
Wind at 2500 m: SW at West, 10-20 km / h during the day, 10-30 km / h at the end of the night.
Wind at 3600 m: North to NW then WNW in day 5-10 then 20-40 km / h, WNW then NW at night 30-40 then 50-60 km / h.
A few isolated gusts of wind along the border and Piedmontese side in the afternoon; they become more frequent at night, locally strong on the Piedmont frontier
From the Pre-Alps to the Combe de Savoie, the wind remains weak, from SW to 1500-2000 m.
SATURDAY 7 DECEMBER
MORE FRESH IN THE MOUNTAIN.
The day begins cloudy clearing quickly during the day on the mountains. In low valleys, temperatures range from 2 in the morning to 10 degrees in the afternoon. Around 1800m they range from -6 degrees at sunrise to 2 in the afternoon.
Isothermal 0 ° C around 2000m.
SUNDAY DECEMBER 8
SUNDAY: DETERIORATES DURING THE DAY
A disturbance should affect Savoie in the afternoon. The sky becomes very cloudy, the clouds give precipitation during the afternoon, snow initially above 2000m and then falling rapidly the following night towards 800 to 1000 m. The wind from west to north-west is more sustained and becomes quite strong in the high mountains. Isothermal around 2500m during the day, falling sharply the following night.
The weather is winter, precipitation is frequent with snow in the mountains to the valley floor significant build up of snow to watch. Northwest wind quite strong in the mountains. Temperatures down.
MONDAY 9 AND TUESDAY 10 DECEMBER
TUESDAY: TEMPORARY IMPROVEMENT.
Precipitation is sparse, the weather seems calmer with the return of some clearings. Moderate northwest wind, remaining locally quite strong in high mountains. Slight rise in temperatures.
WEDNESDAY: NEW DISTURBANCE
The weather is again disturbed, with new snowfall in the mountains, rain and snow limit can be quite low. Temperatures ranging from 2 degrees in the morning to 5 to 6 degrees in plain.
WEDNESDAY 11 AND THURSDAY, DECEMBER 12
The rainy and snowy passages in the mountains remain present on the department. Temperatures change little compared to previous days and remain close to normal season.
Tip of the week
Study the danger rating definitions
It is a new season. Brush up your knowledge by reminding yourself and reading the detailed definition of what each danger rating actually means. It will help you interpret the conditions and the bulletins. You can see these here.
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 ima
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