Wednesday, 28 October 2020

Certainty and Avalanches

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

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 an area forecast is to be applied more locally. Local topographic effects and slight weather variations will make a difference. As a local 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 will always be a process of increasing or decreasing uncertainty. Its never 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 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 being very respectful of the mountains 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 fill your boots.

For skiers, if you couple big uncertainty with risk homeostasis from airbags, carrying the three avalanche rescue essentials of transceiver, shovel and probe and thinking that's enough then have a ponder that its a recipe for feeding the white room spin cycle if you don't stop and think.

The top graphic is pretty obvious. Its pretty certain that natural and human triggered avalanches are predicted above 650m on N to SE aspects and a localised risk present below this altitude from NW through South. Most folk with a brain will avoid the areas above 500m (allow a bit of leeway!) as RED is the colour of danger (obvious!) and will choose to go to safer aspects which in the above is green, which as a colour also maybe falsely gives the assurance of greater certainty. Things become less certain on yellow and very uncertain at orange. This uncertainty is where the risks are, and things become even more uncertain when 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 for you to cross. You can't see the mines but can guess using the wind direction and slope shape as as to where hot spots of weakness might be (a guess - all be it can be an intuitive one but still a guess!) but you have to be very uncertain as you just don't know for sure. Descending on ski's from above and you will likely be going too fast and not see the danger until your in the spin cycle and it's too late.

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 what you don't know - so uncertainty!  And yet graphically on the above for the inexperienced person there is a temptation to look at these localised hot spots in the rose and think "I can avoid them" surely I will recognise these weak areas and can ski/walk/climb around them. 

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 risk level as it's used the most representing the most common and therefore familiar conditions that occur for long periods.  And yet that risk level has the most uncertainty and therefore is the most dangerous for the winter sports person. Make sense?

I suppose if you were to roughly put a % chance of probability 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 in Tignes

Red   98% chance of getting whacked on an aspect with that high level of risk and the Scottish equivalent of Black sometimes (apart from Gaick Lodge our main roads and villages are not in avalanche run out zones so Black does not apply)

Orange  the big problem (to me) be it slices of tray bake sized considerable, or isolated hot spot. If the rose is all orange then in my view its just the same as red but 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 still scary uncertainty as folk think they can recognise the danger hot spots and avoid them. Maybe they can, but then maybe not. A 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 big,  or even if smaller and its above a terrain trap.

Green well either its the best of Scottish neve and you should be climbing with the tools in blue skies, or get the lawn mower out in February.  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 risk when it snows next.

Piss or get off the pot
The above Americanism is pretty appropriate. 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 as mountain folks a lot of good things happen to good people as a reward for getting out there. 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 then take up another sport.  We can reduce risk by managing uncertainty and reduce consequences by equipment and terrain choices, but in the end avalanche prediction and avoidance will never be 100% accurate. I am told knitting is pretty safe if you prefer a more sedate pastime with an easier 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 of course the least predictable with the greatest uncertainty so require extreme caution due to uncertainty. You might think wind slab/storm slab the one that kills the most folk should be "Extra Caution". But, if you think about it you can work out in advance: 

  • 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 based on summer knowledge of your ski patrol/local area, or previous avalanche forecasts that mention temperature rises and surface or deeper instabilities.

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 and after a big snowfall.

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

Avalanche Avoidance and Companion Rescue Practice. There are up to eight independent beacons that transmit a signal at the international standard for avalanche transceivers of 457kHz are  buried in up to 4m of snow at Glencoe Mountain ski resort, conditions permitting

Phillip Rankin, Dr Ian Maclaren, Peter Weir and Paul Moors at the opening of Glencoe Mountain Transceiver training park.
Hamish MacInnes who officially opened the park
In collaboration with Anatom who supplied a wired starter training system to get things going in 2011. Glencoe Mountain Resort provided a piece of snow sure land, help from the staff and some financial help to start the training park 4 years ago.  The original park was opened by Hamish MacInnes the famous mountaineer and rescuer. Winter 2015 money raised by Clachaig Inn at their annual winter series of mountain safety lectures at the hotel provided funding for the new wireless avalanche search training system in place this winter. The hotels owner is a member of Glencoe Mountain Rescue and a friend of both his and Davy Gunn’s (Chris Bell) was lost in an avalanche in Glencoe in 2013 where 4 people lost their lives in one avalanche. The original wired system is now in use at a training park at Glenshee ski centre and it’s hoped to raise funds to get a similar and more effective wireless system in place there. As at Glencoe, the one at Glenshee provides an accessible training venue for local mountain rescue teams, mountaineering groups and off piste and touring skiers.

Practising digging effectively, a crucial 
and often overlooked part of avalanche rescue
The general public has free access to use the training systems which stays out all winter. All they have to do is check in with the Glencoe Mountain staff or  ski patrol to see if it’s already in use that day. Each of the eight buried beacons also has a RECCO reflector inside so that mountain rescue and ski patrol can practise using this alternative search system as well as transceivers. 

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.

The training park beacons are buried deeply in the snow so that searching for them proves difficult, simulating searching a real avalanche for a victim.  As it’s wireless there are no wires to degrade or get cut by shovels as folk dig, and different avalanche burial scenarios can be created from single to multiple victim burials by alternating which buried beacons are transmitting from a control box. When a victim/beacon is found by a searcher, contact with the buried beacon by a snow probe sends a signal back to the control box confirming a success.
I sell avalanche safety equipment. The 3+ is an excellent choice for skiers and also has a Recco strip inside. A discount and some free training to local skiers and climbers who purchase from me. £220 for a 3+ for info email

Every skier going off piste or touring in the mountains should carry three essential items. A transceiver to be located or locate a buried companion, a collapsible snow probe to confirm the victim’s location and a strong aluminium shovel to dig them out quickly. I sell Ortovox shovels and probes and can recommend the Alu240 and Beast shovel to complement the 3+ transceiver or for a pro user the pro alu III shovel and 280 carbon probe. email for details

Glencoe ski patrol practising in the park
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, therefore practise in locating and digging is critical. One of the training beacons is inside a resuscitation mannequin so that digging it out is like excavating a real victim and some care is required. The park importantly provides an opportunity for ski patrol to talk to those practising and emphasise the importance of avoiding avalanche terrain by interpreting the area avalanche forecast and local weather effects and therefore make wise and safe choices avoiding avalanche terrain for the day.

The enthusiasm and support by Glencoe Mountain owner Andy Meldrum and his staff by providing snow sure land, tending to the park and investing in its upkeep is tremendous. A particular mention of thanks to Glencoe Ski Patroller Keith Hill who is always on hand to give sound advice to skiers and boarders and who maintains the park.

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

Don't get buried! But if you do you want to be searchable 
and found FAST!
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. Until now Scotland has only been able to apply two of the three unlike alpine rescue avalanche search where for years all three have been used. 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.

These anecdotal observations and opinions make easy it to forget the victims where triple"H"syndrome has been the killer of which there have been many over the last decades. Anecdote though is not enough, and there is no data from coronial studies in Scotland to support the Trauma versus Triple H debate. See a previous blog on this

One thing is sure, being searchable and getting found quickly increases survival. Some Scottish MR teams already have Recco as part of their search strategy (Tayside, Glencoe, Cairngorm MRT's) and Glencoe and Nevis Range Ski Patrol. I can imagine nothing worse than a victim recovery delayed because a search team did not have a detector and the victim is found to have either a Recco reflector or a harmonic like a mobile phone on them. Recco is of course for "organised rescue". Everyone including Recco and the clothing manufacturers endorse the view that not getting avalanched through education and training is better than needing any search devices which may be too late. However, in the real world shit still happens and unless someone is "searchable" a rescuer cannot find them readily even if the poor victim has bottomed out of the survival curve. 

We should not forget Robert Burnett's remarkable 22 hour survival in the Southern Cairngorms. All victims surely deserve the benefit of the doubt and rescuers throwing all resources at an attempt for a live recovery.
Burnett - 22 hours Buried.  Pic courtesy of Hamish MacInnes
A really good summary of this pretty miraculous survival on this web site 

I sell these reflectors for £25 each. If you have an Ortovox Transceiver then since 2018 one is already built into the beacon as a backup

As "off piste" and "Backcountry" skiing grows in popularity there is every reason to imagine that being more searchable can save lives. Nothing can replace education and prevention, or fast effective companion rescue with transceiver, shovel and probe, but as ski patrols and MR teams take up Recco and the reflectors can be bought and carried then the chance of getting found alive by organised rescue if on scene quickly increases. Recco reflectors may be particularly useful to mountaineers who do not generally carry an avalanche transceiver

I would recommend two reflectors to mountaineers, One front top and one back bottom in a pocket. Recco detection is here in Scotland and its great to see the take up by enlightened Scottish rescuers adopting alpine best practice. I have both the helmet and ski reflectors and very small ones to put in a pocket for sale at

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 Avalanche Transceivers 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. 

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 to search with.

The underslung Recco SAR pod picture right. Searches 200x200m in a minute and the above Austrian crew had just recovered a victim found with it. Based at these sites:

  • 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.


  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.

  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.