Henry's Avalanche Talk, Avalanche awareness, Off piste skiing, snow reports, snow conditions, Val d'Isere, Tignes

Snowpack conditions this week in the Norther French Alps

Before the snow and wind started on Wednesday night, I noticed that the top 10 to 40 cm of the snowpack, was starting to become a cocktail of cohesionless grains of snow by early/mid-week (made up of faceted/angular grains and some surface hoar created thanks to the cold temps) which gave that nice soft top layer a sort of granular feel to it rather than the light smooth feel of fresh new snow. I mention this because even though this top layer was nice to ski in earlier this past week (on most slopes except South due to a a nasty melt crust) is now a weak unstable layer buried under the new snow or snow transported by wind. A number of accidental accidents have happened in the last few days..without serious consecuence (in my opinion because there has not been an enormous amount of snow accumulations and these accidents have involved relatively small slabs with not very much snow in the depostition areas). But the potential is there - I heard serious wooomphing twice today. More snow is predicted for this week and that will add to what is already on top of this weak layer.

There is also another persistent weak layer of cohesionless snow deep down (approx 60-75cm or more down) in the snowpack that dates from the cold snap of early/mid December. This layer is still an issue above 2500 metres or so because these slopes/altitude didn’t get the rain in late December that ultimately had a stabilizing effect on the snowpack from 2500 metres and lower. Large increases in weight, like groups of skiers together on a steep slope can trigger a very large/deep slab avalanche due to this deep weak layer.

Météo France is warning people to still be careful on steep East to North to West slopes above 2200-2400 that could be susceptible to the weight of a group of skiers - and if there’s more snow (as is predicted as the week goes on!), these slopes could become more and more sensitive and deeper instability is predicted e.g. the weight of even a single skier could very easily trigger a large slab avalanche.

Have Fun and Be Safe!                

Off Piste & Avalanche Awareness Talks in Val d'Isère: Week of 1 February:

Monday 15.30 sharp Basic Talk at the Moris in Val d’Isère

Weds  18.00 sharp Basic Talk at the Pacific Bar in Val d’Isère

You need to show up at least15 mins before the talk to take advantage of the deals on food & drink!

Tickets are €7.50 (one person under 18 per adult free) and includes great deals on food and drinks at each place! Pre-booking on line price is: £6 on www.henrysavalanchetalk.com (if you can’t come to a talk see our on-line talks on the web site)

HAT is taking the Talks on-snow this year for people who want to learn more in Val d’Isère & Tignes!
See www.henrysavalanchetalk.com for more info on these practical short courses  

New snow predicted, but high instability

It is and has been very, very cold over the past week with temps getting down below -20 at 2000 metres at some point on most days. These cold temps have helped to loosen up the old snow and make for some really good skiing (see blog entry on December 15 http://www.getoffpiste.com/2009/12/theres-some-nice-turns-to-be-had-out-there.html), BUT this same layer of snow that’s nice for skiing now is also a potential weak layer that will be sitting under the new snow predicted for next week (80cm in some places by Wednesday.

In most places where there is new snow next week, there will be a weak layer underneath it. I’m predicting that there will be a lot of instability out there in most of the Northern French Alps.

As we say in the Basic Henry’s Avalanche Talk, “there are many different layers of snow in the snowpack and some of these layers are stronger than others; sometimes there can be weak, fragile layers in the middle of the snowpack or even at the bottom”.  There is a weak layer in most places in the Northern French Alps especially above 1500 metres. So be careful as more and more new snow comes down on top of it.

To learn more about things like weak layers and how to have fun and be safe off-piste, come to an avalanche talk (see below)

Have Fun and Be Safe!

Henry

 Off Piste & Avalanche Awareness Talks next week:

Monday  15.30 sharp Basic Talk at the Moris in Val d’Isère

Tuesday 17.45 sharp Basic Talk at the Bagus in Tignes

Weds      18.00 sharp Basic Talk at the Pacific Bar in Val d’Isère

You need to show up at least15 mins before the talk to take advantage of the deals on food & drink!

Tickets are €7.50 (one person under 18 per adult free) and includes great deals on food and drinks at each place! Pre-booking on line price is: £6 on www.henrysavalanchetalk.com (if you can’t come to a talk see our on-line talks)

HAT is taking the Talks on-snow this year for people who want to learn more in Val d’Isère & Tignes!
See www.henrysavalanchetalk.com for more info on these practical short courses  

There's some nice turns to be had out there, but you gotta walk a little get them as nice as Tony in this vid.
The v cold temps are loosening the snow up and making it nice to ski in. The top layer is generally an older snow layer which is a combination of depth hoar, surface hoar and angular grains formed due to the cold temps and thin'ish' snowpack (you can hear the 'hissing' of the snow as Tony goes by in this video - the hissing is due to the texture of this light granular snow known as 'loud powder' by some. It's really nice to ski in for now, but will be a v unstable layer when the next snow comes down on top of it.

Snow Report

This past week started out with ‘precipitation’ in the form of rain most places up to quite a high altitude for this time of year. The highest the rain and humidity went was on Sunday night and Monday when we had to go up to close to 3000 metres to get to snow that was only moderately humid. However during the day on Sunday and on Tuesday it snowed lower down and we had some good skiing in pockets that were protected from the wind. We got about 40 cm of new snow this past week in much of the Northern French Alps above 2500 metres – more in places protected from the wind like just under ridges. 

It looks like there will be a bit of snow over the weekend with colder and COLDER temps (but winds calming a bit compared to today). Then continued cloudy with snow showers off and on mixed with clearing spells and very cold temperatures into the middle of next week .

Snow Stability

This past week’s new snow has helped to cover the ground better especially above 2500 metres, but there is a weak layer under the recent snow in many places especially above 2500 metres; this weak layer was partly responsible for a couple of the accidental releases and artificial releases (with explosives) over the last week. That weak layer is consolidating/stabilising at lower altitudes and on other slopes where it has been warmer (since the end result of warmer temperatures is an increase in stability of the snowpack especially if the temperatures cool down afterwards). But the best snow for skiing at the moment is on the slopes where the snow is lighter and colder (on north’ish facing slopes protected from the wind and at higher altitudes: like above 2300-2500 metres). This is exactly where the weak layers are the most evident and where instability will increase due to the increase in load (weight) from the snow in the next snowstorm(s).

Tip of the week - weak layers continued: Remember the tip from last week’s report, “that there are many different layers of snow in the snowpack and some of these layers are stronger than others; and sometimes there can be weak, fragile layers in the middle of the snowpack or even at the bottom”.  Most of the time, during the winter, the best lightest snow is on the more unstable slopes (this is why most accidents happen on north’ish facing slopes in the colder winter months during the season):  and this will most probably be the case if and when we get a good dump of snow this weekend or on Tuesday.

Having fun and being safe off piste is all about balancing what seems like a contradiction: “that the best snow is very often where the snow is the most unstable”. Striking a balance between having a great time in great snow and keeping it safe is not rocket science, but it does take some learning and thinking.

To begin to learn how to reconcile the search for good snow leading you to increasingly unstable areas, see www.henrysavalanchetalk.com for information/education on-line or come to one of our talks.

Have Fun and Be Safe!

Off Piste & Avalanche Awareness Talks
Monday  15.30 sharp Basic Talk at the Moris in Val d’Isère
Tuesday 17.45 sharp Basic Talk at the Bagus in Tignes (you need to be at the Bagus by 17.30 to take advantage of the deals on food & drink!)
Weds      18.00 sharp Basic Talk at the Pacific Bar in Val d’Isère

Tickets are €7.50 (one person under 18 per adult  free) and includes great deals on food and drinks at each place! Pre-booking on line price is: £6 on www.henrysavalanchetalk.com
HAT is taking the Talks on-snow this year for people who want to learn more in Val d’Isère & Tignes!
See www.henrysavalanchetalk.com for more info on these practical short courses  

Snow Report

It will continue to snow off and on this weekend and at least through Tuesday in the Northern French Alps. That’s great news for this early season as one of the biggest dangers off piste at the moment is hitting crap (which is the technical term for rocks, tree stumps etc.) under the snow cover.  Hopefully that will be resolved by the end of the week with the new accumulations.

Snow Stability

The total snow cover (what we call the snowpack) will be evolving over the next few days as we get a series of new snowfalls which will be adding new distinct layers to the snowpack. All of this new snow will be sitting on other different layers from snowfalls this past week and before. The important thing to remember is that there are many different layers of snow in the snowpack and some of these layers are stronger than others; and sometimes there can be weak, fragile layers in the middle of the snowpack or even at the bottom.

Last week there was a couple of accidental avalanches in the Northern French Alps, one in the Haute Tarentaise area of Savoie (which is basically the region of La Plagne, Les Arc and the Espace Killy) on a slope facing North West at about 2300 metres (remember that most accidents happen on North’ish facing slopes in the winter months, contrary to popular belief). There’s a good chance that instability in the snowpack will increase with these new snowfalls and strong winds out of the West over the weekend – the new snow will be putting stress on old weak layers and building new varied layers in the snowpack… but the skiing will most likely improve too!

To learn how to reconcile improved skiing conditions with increased instability in the snowpack (layers of snow etc.), see www.henrysavalanchetalk.com, come to one of our talks and join one of our new on-snow courses. And of course we’ll be updating you each week with a snow report!

Have Fun and Be Safe!

PS A thank you goes out to Cécile Coléou and the team from Météo France and Centre d’Etude de la Neige for providing much of the weather and avalanche forecast information that we use to make these snow reports complete.

Off Piste & Avalanche Awareness Talks
Monday  15.30 sharp Basic Talk at the Moris in Val d’Isère
Tuesday 18.00 Basic Talk at the Bagus in Tignes (you need to be at the Bagus by 17.30 to take advantage of the deals on food & drink!)
Weds      18.00 sharp Basic Talk at the Pacific Bar in Val d’Isère

Tickets are €7.50 (one person under-18 in free per adult) and includes great deals on food and drinks at each place!
Pre-booking on line price is: £6 on www.henrysavalanchetalk.com

HAT is taking the Talks on-snow this year for people who want to learn more in Val d’Isère & Tignes!
See www.henrysavalanchetalk.com for more info on these practical short courses

Spring Skiing: hoping for HOT DAYS and clear COLD NIGHTS

If you're skiing off-piste this holiday weekend then you should be hoping for the same thing! As hot days and clear cold nights is what it will take to build a nice smooth melt-freeze layer. It is forecast to do just that.

Be careful of slopes above you. There's been a lot of new snow over the last few days in much of the Norther and Southern French Alps. Some big avalanches will be coming down as the slopes warm up - this will be especially true near the Italian border.

See below for a summary on what real spring skiing is (not slush) and how the melt-freeze layer can make for a great day out. 

(click to enlarge)

SPRING SKIING and the Melt-freeze Layer

 Melt-freeze Cycles: Understand the ‘melt-freeze cycles’ and have fun with spring skiing!

Once the new snow melts during the day and then freezes at night (1 melt-freeze cycle) a few times in succession after a snowfall, the top snow layer begins to form a crust that gets deeper and stronger after each melt allows free water to drip down and re-freeze during the night. Any given ‘melt-freeze’ layer becomes stronger with each cycle of melting and freezing due to the deeper penetration of each melt during the day, which then adds more depth to the potential frozen layer at night. If untouched, the top of this frozen layer is smooth and solid first thing in the morning, then it becomes progressively softer as the warm sun and increased temperatures melt it as the day goes by. This process starts on east faces because they get the sun first thing in the morning, then south, then west (north faces at 2500 metres don’t normally get a melt freeze layer on them until late April due to lack of sun).

 For good skiing!

The trick is, after a couple of good melt-freeze cycles have created a solid layer on a slope, you need to get on that slope when the snow surface is smooth and solid with only 2 or 3 cm’s of soft melted snow on top (these are generally slopes that have been in the direct sunlight only for an hour or so e.g. an East facing slope at 9 or 10). Then you need to get off those slopes when the snow surface begins to get too soft and mushy or you’ll start breaking through, which is dangerous for your knees. AND the slope may be unstable due to all the melting - then avalanches can be a problem.

 In sum:

After a solid melt-freeze layer has formed and there has been a good melt during the day, it needs to freeze well the night before; the ideal is a cool clear night with minimums of –2 degrees (or lower) at 2000 m. This will allow the melted parts of the layer to freeze solid again from that altitude up. Then, in the morning, you look to get on the east facing slopes first thing, 9 AM, because the sun rises in the east and therefore those slopes get the sun first. Then you move to south facing slopes, then west. Do this right and get some of the best skiing of the season.

 Aside from a night that is not cool enough, the only thing that gets in the way of great spring skiing is the nasty ruts in the snow that people leave behind because they either ski spring snow slopes (slopes that get lots of sun in spring: E,S and W) before the melt-freeze layer has formed or they ski the slopes too late when they are too soft and mushy.

Avalanche Rating of 4 out of 5

It's snowing so much that the avalanche rating has gone up to 4 from the Northern French Alps: in Savoie down the Italian border to the Southern French Alps: Hautes-Alpes, Alpes-de-Haute-Provence even as far down the Alpes Maritime. That's almost as far as Nice! Even in Corisca the rating is 3 out of 5... See the avalanche forecast from Météo France you can translate these forecasts by copying and pasting the text into Google Translate!

And it's snowing down pretty low too - photo below is at 1850 m in Val d'Isère. I'll be skiing off piste as usual, but will be very careful over the next couple of days.

Season coming to an end...

..and many of you are either sitting in your green gardens, sailing, playing golf, tennis or football, but for those of you who live out here, are skiing out here or just enjoy knowing what's going on in the off-piste in the region, Wayne Watson from Alpine Experience, gives a great description of his morning and the snow conditions off piste in the Espace Killy at the moment as more snow comes in and winter returns once again:

Wow, what a fabulous morning! It had to be some of the best spring snow, without the sun, that I can remember in quite some time. Only a centimetre or two of fresh snow fell overnight, but it was enough for the new snow to ‘eat into’ the surface layer and soften it to a nice texture without the warmth of the sun being needed to melt the frozen surface. It was +5C at 8AM with grey skies and a foehn wind of up to 80kph blowing it didn’t look like it was going to be such a good ski, but once on the snow I knew we were in for a good day. We started out with an excellent Alti-port/Lavachet, followed by a good Cocaine Sud, then a stunning Cocaine Nord, and then a superb Lavachet but from the top through the avalanche barriers. From there we skied a funky Familial to the bottom arriving around 1:20PM to finish off Jean R’s 93rd and last morning of a terrific season. We’ll miss his company and his excellent photographic input to the website. Merci beaucoup Jean! 

And here's a photo from Jean Ribart of Wayne skiing some of the nice spring snow described above:

More snow for Sunday

I know most of you aren't going to be out skiing in the mountains again until next season, but for those of you who are either out here now or will be soon, here is a quick update on what's happening and what's going to be happening in the Northern French Alps!

The conditions have been pretty good for spring skiing over the last few days with clear, cold/freezing nights down to 2000 metres following hot melting days. The off-piste has been kept in pretty good conditions (i.e. smooth spring snow slopes) since there haven't been too many people around to trash the snow by skiing these slopes too late and leaving ruts behind (for an understanding of what makes nice smooth spring snow condtions see my update on the melt-freeze layer on April 1 ) Otherwise, it should look like this when you ski it:

For the next few days: tomorrow is supposed to be clear in the morning then windy (out of S,SW), warm (max of 9° at 2000) and cloudy then snow showers in the evening. then Sunday is supposed to bring in snow especially around the Italian border (surprise!). Total snow 25 cm at 2500 m above 2000 m then more snow Sunday night as the winds move to westerly and the rain snow limit moves down below 2000 metres (another possible 40 cm along the border during the night!) and things begin to get cooler than average for the season. Clearing on Thursday. Each recent snowstorm has been followed by quite a bit of instability in certain areas especially on the lee side of ridges, passes and peaks. For more information on that see the Météo France avalanche forecast (you can always translate it on Google).

These updates will probably become less frequent as the season comes to a close and many of you are off doing other things..., but thanks for your interest during the season and please stay tuned for general HAT updates and other interesting things that we get up to during the off-season! All the best, Henry

snow conditions today

I started out looking for soft winter snow like the great snow we had yesterday, but soon found that if I wasn't above 2600 m and skiing due North, that I was hitting a nasty sun crust. so I changed the plan completely and went for spring snow (East to South to West in that order above 1800 m). I was not really sure if the melt freeze crust (see post http://www.getoffpiste.com/2009/04/big-snow-no-joke.html - the part on spring snow) would hold up, but it did! 

So had great spring skiing today thanks in large part to the fact that the slopes hadn't been trashed yet by people skiing them too late (again for explanation on this, see the above post from Weds where I explain how to get great skiing in spring when everyone is saying how slushy or hard it is)!