Tuesday 16 January 2024

Avalanche Jenga Season

Recco Training at Glencoe Mountain
 Nevis Range and Glencoe Professional Ski Patrols











These musings by a now almost, but not quite, burnt out arm chair pundit who has been buried  and also weilded a shovel too many times in avalanche recovery, should not be taken as gospel, just my personal opinion. Always seek out other opinions. 

Forecasting and local avalanche risk assessment is about prediction based on past and future weather forecasts, therefore it will always be uncertain, and a game of probability. Especially when what is an area forecast is  applied more locally. Local topographic effects, and slight weather variations will make a difference. 

As an example. There may be a difference between the Glencoe Mountain ski area weather and snowpack at the East end of Glencoe, and the Ballachulish Horseshoe circuit at the West end. Interpretation and application of forecast information to a trip is a process of increasing or decreasing uncertainty. Its rarely 100% certain. That's why a degree of flexibility in decisions and dynamic risk assessment is essential during a day out in the mountains. Conditions might be quite different to what you thought, and plans will need revised. Mountaineers and skiers who reach pensionable age have become good observer's of small and subtle weather and snow pack detail, and possess a spatial awareness while also being very respectful of the mountains while  journeying among them. Its not required to achieve an objective some days, and quite enough to listen to what the mountains are saying to you. This may be go home, or it might be todays the day, so get the rope/ski's on and enjoy.

In off piste skiing and touring, you couple uncertainty with risk homeostasis from airbags, carrying the three avalanche rescue essentials of transceiver, shovel and probe. Have a ponder that its a recipe for feeding the white room spin cycle if you don't stop and think. The decisions you make with the presence of consequence reduction kit such as these should be no different to that ones you would make if you left them behind. The idea is not to get avalanched and need them. Acknowledging human fallability and uncertainty, they are there of the unforseen "Black Swan Event", a phrase nore commonly used in the world of finance, for an extremely negative event or occurrence that is impossibly difficult to predict.



The top graphic is pretty obvious. Its pretty certain that natural and human triggered avalanches are predicted above 650m on North to South Eeast aspects, and a localised avalanche risk is present below this altitude from the North West through South. Most folk with a brain will avoid the areas above 500m (allowing a bit of leeway!). RED is the colour of danger (obviously) and folk will choose to go to safer aspects, which in the above is green, which as a colour the colour of greater certainty of safety. Things become less certain on yellow, and very uncertain at orange. This uncertainty especially at Orange is where the risks are, as the risks are localised. Yellow the probability of getting caught is less, but still uncertain, stick a localised considerable orange strip in there and you have a mine field of uncertainty lying in wait.

How do you mange or minimise risk if you have to travel on these aspects, or choose to ski them? Well you don't manage the risk with any degree of certainty as you just don't know for sure where weak spots are, and you will for sure not know the true propagation risk from a trigger. You can't minimise a risk you don't know.  For the inexperienced person there is a temptation to look at these localised hot spots in the graphic and think you can avoid them, thinking, surely I will recognise these weak areas and can ski/walk/climb around them. Folk dont though, which is wahy folk still die in Scottish avalanches.

So my take on why it is that most folk get whacked when the risk is considerable or localised, is that being outdoor optimists (as we all are), and perhaps having got knackered climbing up a mountain or skinning into a valley, or maybe having a bluebird pow day, folk get used to that middle risk level, as it's used the most representing the most common and therefore familiar avalanche conditions that occur for the longest periods.  That  risk level has the most uncertainty and therefore is the most dangerous for the winter sports person IMHO

I suppose if you were to roughly put a % chance of probability of being avalanched on the European avalanche scale you could say that:

Black 100% chance of getting whacked while either minding your own business, in Galtur or being suicidal side piste in Tignes

Red   98% chance of getting whacked on an aspect with that high level of risk. The Scottish highest level of risk. 
 Apart from the Gaick Lodge avalanche, our main roads and villages are not in avalanche run out zones so Black does not apply. If an aspect is RED in the forecast then go to the pub or climbing wall or find a nice safe low level walk or ski run.

Orange   If the rose is all orange then in my view its just the same as red, just a tad less obvious. You have a very high chance of getting whacked. Stick some localised Orange risk in among yellow, then it becomes 50/50 and that's scary uncertainty, as some folk think they can recognise the danger hot spots and avoid them. Maybe they can, but then maybe not. Its certainly dicing with the big white avalanche room. This would be
 low angled slope day for me, well away from run out areas. The more times you roll the dice in the orange/considerable risk zone then the more chance you won't be needing your old age pension. 50/50 isn't odds, its worse than Russian Roulette!

Yellow maybe a 40% of getting away with it, but victim triggered death is still very likely if you hit a hot spot and it propagates into something bigger. Even if smaller avalnches can be lethal especially if it takes you into a terrain trap. This is true of all terrain features you can end up in if avalanched.

Green Well, either its the best of Scottish neve and you should be climbing with the axe and crampons in blue skies, or be getting the lawn mower out. If its the best of Scottish neve and its a sunless aspect then watch out next time it snows as there's could to be something growing on the top surface like hoar or faceting that will give a higher avalanche risk when it next snows fi its early winter especially.

Piss or get off the pot
Only one thing is for sure, we can only manage uncertainty up to a point. We live in a chaotic universe, bad things happen to good people, and a lot of good things happen to good people as a reward for getting out there making the effort. I think we have to accept that the line between the best day skiing of your life, and getting taken out by a slide is pretty close if you want to ride the powder days on higher angled slopes. If you don't accept that take up another sport.  We can reduce risk by managing uncertainty, and reduce consequences by equipment and terrain choices. Avalanche prediction and avoidance will never be 100% accurate. I am told knitting is pretty safe, if you prefer a more sedate pastime with a surer risk assessment.

Avalanche Types and Uncertainty
Some types of avalanche are more predictable i.e "certain" and some less so and some types of avalanche risk can be more easily seen in tests and observations. The ones that concern us the most are the least predictable with the greatest uncertainty so require extreme caution. Windlsab is the biggest enemy. Have a think about the following:

  • Aspects that might be affected from a weather forecast, and very importantly observed wind direction 
  • Angle of slope based on contours, precipitation type and deposition 
  • Altitude, and what the precipitation is, and its likely rate of deposition 
  • Anchored to. Whts under the snow,  based on summer knowledge of your ski patrol/local area.  Or avalanche forecasts that mention  surface or deeper instabilities within the snow pack.

Wet snow release triggering a weakly anchored slope
















Powerful wet snow glide avalanche that takes everything in its path. Buachaille Etive above Lagangarbh. You don't want to be in here if its raining during a thaw just after a big snowfall.

Persistent slab, skier triggered slab March 30th 2013 Glencoe Mountain Ski Area - Fatal


Organised rescue teams use RECCO which is harmonic radar that can also be used from a helicopter. RECCO is a standard search tool by mountain rescue in Europe. Three Scottish mountain rescue teams, and threes ski patrol's use it. No search and rescue helicopters have adopted it in the UK for avalanche rescue to date, but the hand held can be used from a helicopter with an adaptor system from a 3rd party manufacturer. I have one here in Glencoe as I am also the UK trainer for Recco.

A skier going off piste or touring in the mountains should carry three essential items. A transceiver to be located, or to locate a buried companion, a collapsible snow probe to confirm the victim’s location, and a strong aluminium shovel to dig them out quickly.

Recovery of buried companions in an avalanche is time critical with a 90% survival if victims are located and dug out within less than 15 minutes. After this time survival is very poor. It follows that practise in locating and digging out a victim is critical. 

Killin Mountain Rescue and a group of Freeride skiers using the  Glencoe Mountain Avalanche training park


Recco is another important part of the organised rescue strategy. Education and avalanche avoidance is primary, being found early by companions if it goes wrong is vital, and prior practice makes this work. Organised rescue requires a triple response: Dogs, Recco and Probe Lines. Survival is time critical. Much has been made of trauma being the main factor in poor survival in Scottish avalanches. Largely based on a few tragic avalanche incidents where trauma has been the dominant factor.

Anecdotal observations and opinions make easy to forget the victims where triple"H"syndrome has been the killer, of which there have been many over the last decades. Anecdote is not enough, and there is no data from coronial studies in Scotland to support the Trauma versus Triple H debate.

Being searchable and located quickly increases survival. Some Scottish MR teams already have Recco as part of their search strategy (Tayside, Glencoe, Cairngorm MRT's) and Glencoe Ski Patrol. There has been a demand for buying two single Recco reflectors to carry by mountaineers. One in a front pocket and one in back (on the person. never the rucksack or ski). Reflectors are light, passive requiring no battery and small. For the burdened winter mountaineer already with a heavy pack it provides a cheaper and lighter option than shovel, probe and beacon.

I can imagine nothing worse than a victim recovery delayed because a search team did not have a Recco detector and the victim when recovered is found to have either a Recco reflector or a harmonic like a mobile phone on them. Recco detectors are of course for "organised rescue". Recco and the many clothing manufacturers who sew in the Recco relflectors, endorse the view that not getting avalanched through education and training is best. However, in the real world shit still happens, and unless someone is "searchable" a rescuer cannot find them quickly. Even if the poor victim has bottomed out of the survival curve a vistim recovered quickly reduces rescuer risk exposure, and provides some closure to waiting family. 

How does a Recco Reflector work?

  • Professional rescuers can quickly pinpoint a buried reflector-equipped person’s precise location using harmonic radar. Often quicker than a transceiver.

  • This two-part system consists of a RECCO R9 detector used by professional rescue groups, and RECCO reflectors that are attached to clothing, helmets, protection gear, and boots worn by skiers, mountaineers and riders and other outdoor users.
  • When used in conjunction with a RECCO Detector, the reflector's diode mixer acts as a harmonic generator to produce multiples of the frequencies received from the detectors.
  • The returned signal is translated into an audio tone whose volume is proportional to the returned signal, and by means of volume control, a trained rescue operator can literally go straight to the buried reflector once a signal is detected.
  • It is a non-powered device meaning that it never needs to be switched on, will never lose signal strength and needs no batteries to function. It is maintenance free and has a virtually unlimited life.
  • In total more than 900+ search & rescue organizations in the world endorse it.

The Recco Rescue System is different from an Avalanche Transceiver because its a small band-aid size sticky transponder which is not powered, the reflector can be applied to your boots or helmet, the Recco detector does not contain any antennas and cannot be picked up by an avalanche beacon, the Recco detector has a range of over 200 metres which professional mountain rescue teams can pick up in the case of an avalanche.

Due to it not being a passive device the reflector will not lose signal strength and no battery to malfunction. 

We should not forget Robert Burnett's remarkable twenty two hour survival in the Southern Cairngorms. All victims surely deserve the benefit of the doubt, with  rescuers throwing all resources at an attempt at a a live recovery.
Robert Burnett - 22 hours Buried.  Pic courtesy of Hamish MacInnes

A really good summary of this pretty miraculous survival on the web site 


The hand held R9  Recco detector is the size and weight of a hard back book and easy for rescuers to get to the scene and search with.

The underslung Recco SAR pod picture right. Searches 200x200m in a minute and the above Austrian crew hadsjust recovered a victim located with it.

Recco Helicopter based SAR is based at these sites, with more added including a prospective private North of England site soon:


  • Switzerland – Zermatt, Sion
  • Italy – Aosta, Bozen, Trento
  • Austria  – Hohenems, Innsbruck, Linz, Graz
  • Norway – Alesund, Hastad, 
  • Sweden – Ostersund 
  • Canada – Snohomish Helicopter Rescue Team, Snohomish, WA
  • United States – Alpine Helicopters, Canmore AB

Live recovery of a victim located by her Recco reflector
 
Glencoe Ski Patrol doing a precautionary combined 457mhz transceiver search and Recco harmonic search on the "Fly Paper". The R9 detector searches both, and at close range can find many other harmonic devices such as mobile phones.




2 comments:

  1. Good read Davy.

    1 = no snow
    2 = off piste is moguls
    3 = off piste is tracked
    4 = off piste is fresh
    5 = lifts are shut

    Obviously not a responsible way to look at things. BUT... for many ski resorts , especially big popular ones in alps it is very close to reality of situation. Something many formal education sources overlook is that skiers are actively looking for fresh snow on 25+ degrees slopes, as its fun skiing. However with fresh snow the risk is almost always going to be level 3 or more. Of course a climber wouldn't go near such a slope on foot if it could be in anyway avoided. But in Scotland we can often only ski where the snow has drifted - which is an added complication.

    Now as a skier I fully accept that lvl 3 = 'considerable'. The problem is that at level 1 or 2 the snow off piste is often not that fun to ski either... (boiler plate scares me too!). Have thought about this a lot over the last 2 weeks and the only conclusion I can come to is that skiers seeking fresh snow (including myself) need to learn to be much smarter about terrain decisions / traps and the consequences of what could potentially happen if something released. The only other option is to stick to piste carving.

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  2. Thanks Doug. I wouldn't give up on the off piste! Back in 2005 Tignes more or less conceded that it's selling of itself as an off piste mecca(SPOT- ski the powder of Tignes)had created the environment that had caused an icrease in avlanche fatalities. They even had/have a dedicated freeride off piste lift served area at the col de Ves and at one time had the first ARVA park, all to mitigate the attrition rate. The chef de piste at that time Jean Louis Touaillon is a great supporter of FIPS and BASP and is now heading up the pistuers at Chatel and for the Sochi winter olympics. The best skiing is when there is some risk, and I for one would not think of stopping doing it. Managing the risk means accepting the uncertainty and replacing it with knowledge, judgement and ways of reducing the consequences. I didn't want to use the gulch as an example, but as a terrain trap it changed any risk assesement as no matter what you or frinds carry or wear the consequence of going in it are huge. This is an example of looking and talking about conditions and running through scenarios of consequences before skiing an area and one that every self respecting guide would intuitively be doing as well as analyticaly doing profiles and other measures to support (or not) their intuition. I dont know that avlx education is anymore than making folk think, look and feel and importantly talk through where and what they are doing.

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