Big snow has started falling! This will set us up for the season, but will bring high avalanche danger!
Have woken up Friday morning to see heavy snow falling and significant snowfall since midnight. These trees in Val d’Isere had no snow on them last night.
These are the snow depths that the new snow will fall onto. You can read a report about the base of the snow pack that we wrote on Tuesday click here
We’ve had a great week’s off-piste skiing, with regular top-ups of 10 to 20 cm fresh snow virtually every other day. We alternated between flat light conditions and snowfall one day and clear blue skies with fantastic powder the next.
On Tuesday there was a blue sky powder day and there were a few triggered avalanches triggered by skiers. This is evidence that the greatest risks are wind slab on leeward slopes.
These all took place on NE, E and SE facing slopes which had wind slab on them. These photos from Avalanche Geeks shows examples of skier triggered avalanches. The group were on a training course and spotted the risk and managed their decision making to stay out of trouble. You can read about it here
Visibility has been very tricky at times. To make the most of our skiing on those flat-light days we skied among the trees, where we could see a bit better.
What is the current avalanche risk in the Northern French Alps/Savoie?
At the time of writing (13th Dec) the avalanche risk is 4/5 (High). Over the week covered in this extended forecast, however, the danger rating will stay high or at least considerable (3/5). A huge amount of snowfall is expected in the N French Alps and surrounding area. Will we get a 5/5? That would be unusual. (Update 1430 : the resort has now confirmed it is a 5/5). The Tignes piste patrol report that most PIDA bombing activity is causing the slabs to release this morning.
The outlook is unsettled. The first storm is in cold weather, but then it will warm up across the N French Alps. It will be coldest on the French /Italian border. But 0C could rise to 2700m. This will humidify the snow lower down and damage the quality of the powder.
This Friday/Saturday, we may receive a metre of fresh snow in cold weather.
Check out what the different avalanche danger ratings mean.
This fresh snowfall will be accompanied by high winds, causing accumulations of snow through drifting. This process is known as ‘wind loading’.
What does this mean for off-piste skiers and snowboarders?
Large accumulations of snow will lead to a cycle of natural avalanche activity during and just after the storms. These are referred to as “direct action avalanches”.
The snow accumulations will also make the risk of accidental avalanches, i.e. those triggered by people, very high.
The best advice during this time is to stay on and around slope less than 30° steepness.
Where is most at risk at the moment?
The areas at greatest risk are wind loaded slopes so E and NE look the most dangerous. However, the bulletin is highlighting high risk (danger rating 4) on all slopes due to the considerable snowfall.
The dangerous slopes will become evident during and after the snowstorms that are predicted. This will be indicated in the daily avalanche bulletins. Also look out for recent avalanche activity, which is likely to be on those leeward slopes that have been loaded with snow drifting by the wind.
Due to the wind during the storms, the biggest danger will be on slopes where the snow has drifted in and built up. These slopes are generally on leeward sides of the mountain and other areas that are sheltered from the wind. This is where you are more prone to trigger a slab avalanche. Be careful because it’s more tempting to ski in these places because there’s more snow!
The danger is increased dramatically if there are ‘terrain traps’ below. In fact, the clearest answer to where there is the biggest risk is on slopes above dangerous terrain features like cliffs, trees, holes and narrow valley bottoms.
What is the likely avalanche activity this week?
There will be a lot. Both natural direct action avalanches and avalanches triggered by blasting or skiers. Look at the results of the piste patrol’s avalanche blasting to get a sense of the danger. This will show you if the slopes are stable or unstable.
How does the forecast look for the coming week?
FRIDAY 13 DECEMBER – STORM
The weather is gloomy and snow is frequent, continuous in the morning then in the form of showers in the afternoon. In the mountains the wind from west to northwest with gusts that exceed 80 to 100 km / h. The visibilities are poor in the mountains, with the formation of snowdrifts.
The rain and snow limit rises around 1100 m in the morning and then lowers around 700 to 800m in the middle of the afternoon.
Temperature rises Friday night with rain up to 1500 or even 1800m
Snow quantities until Saturday morning: 30 to 40cm around 1800m, 40 to 70cm above 2000m.
Isotherm 0 ° C: around 1500m then 1200m during the day going up to 2000m the following night
Isotherm -10 ° C: around 2500m.
SATURDAY DECEMBER 14 – WARMER and STORMY
The clouds remain numerous covering summits. Snow is frequent but less than Friday with a rain/snow limit between 1400 and 1800m. The precipitation stopped the following night. 20 locally 30 cm of additional snow is possible above 1800 to 2000m.
Northwest wind remaining strong in the mountains with gusts of 60 to 100 km / h
Isotherm 0 ° C around 2000 then 1700m
Isotherm -10 ° C around 3500m
Maximum temperatures 7 to 9 ° C in the plain and low valleys, 0 to 4 ° C around 1800 to 2000m.
SUNDAY, DECEMBER 15
STRONG WIND IN THE MOUNTAINS
Slow improvement, the clouds remain numerous for the day with little or no precipitation, the summits are covered with clear spells during the afternoon.
0 ° C rising to 2000 at 2200m.
Wind west to southwest remaining fairly strong in the mountains, gusts from 60 to 80 km / h.
Maximum temperatures 0 to 3 degrees around 1800 to 2000m.
MONDAY, DECEMBER 16TH, – FOEHN
Partially sunny day; some cloudy periods, and more cloud on French/Italian border, where precipitation is possible the following night.
0 ° C down to 2100m near the border, but 2700m further west
Wind southwesterly in mountain gusts of 60 to 80 km / h.
TUESDAY: NO CHANGES
More clouds and showers possible on the border where showers are possible. Foehn blows
0 degree 2100 m towards the border, 2400 to 2700m elsewhere.
Unsettled weather from the Mediterranean overflows the border with light precipitation, snow above 1800m. Foehn always in place.
Isotherm 0 ° C around 2100 then 2400 m.
THURSDAY: LITTLE CHANGE
The weather remains temporarily cloudy with light precipitation,
0C around 2100 to 2400m. the wind remains in the South
FRIDAY 20 DECEMBER and SATURDAY 21 DECEMBER
Clear spells and cloudy periods bringing a few showers. Temperatures remain mild and well above normal.
Tip of the week
Get ready for the season, know how to manage your risk. Come to one of our off piste awareness talks
There are two in Val d’Isere at the Hotel Galise at 1745 on
Henry will deliver an easy to understand explanation of risk management in the Essentials and explain how and why avalanches are triggered in the in-depth talk. You can read more about them and prebook here.
There may be tickets for sale at the door, but we have limited capacity.
There are also two talks in London on 7th and 8th January