Avalanche basics: what you need to know

An average of 100 people die in avalanches in the Alps every year. The sad reality is that most of these accidents could have been avoided. Not through expensive equipment or years of experience, but through solid basic knowledge.

This guide covers the fundamental avalanche basics that anyone heading off-piste in winter needs to know. From avalanche types and avalanche bulletins to emergency equipment and the right behaviour in the mountains.

Not every avalanche is the same. The type of avalanche determines its speed, destructive force and likelihood of being triggered. For ski tourers, three types are particularly relevant:

Slab avalanche: the most dangerous type

A continuous layer of snow releases on a weak layer and breaks away as a slab. It can be recognised by its characteristic crown fracture.

• Speed: 80–300 km/h
• Trigger: Usually people
• Risk: 90 per cent of all fatal avalanche accidents
• Typical terrain: Steep slopes of 30–45 degrees, wind-packed snow

Loose snow avalanche

Individual snow crystals release at a single point and pull more snow with them, like an overturned hourglass.

• Shape: Pear-shaped, starts small
• Risk: Usually small, but can grow large
• Typical terrain: Very steep terrain, after fresh snowfall

Wet snow avalanche

Water-saturated snow loses its cohesion and slides downhill.

• Timing: During the day as temperatures rise, in spring
• Speed: Slower, but with enormous mass
• Risk: Hard to survive if buried, but highly destructive

The avalanche bulletin is your most important planning tool. It is issued daily by avalanche warning services and describes the current risk situation.

The 5 danger levels:

• Level 1: Low: the snowpack is well bonded
• Level 2: Moderate: the snowpack is weakly bonded on some steep slopes
• Level 3: Considerable: the snowpack is weakly bonded on many steep slopes
• Level 4: High: the snowpack is weakly bonded on most steep slopes
• Level 5: Very high: unstable snowpack, large spontaneous avalanches likely

What you must pay attention to:

• Danger level does not mean safety: most accidents happen even at level 2
• Consider altitude bands: levels often differ at different elevations
• Consider aspect: where is the main danger?
• Understand avalanche problems: wind-drifted snow, old snow, wet snow
• Check the trend: are conditions improving or deteriorating?

Important avalanche warning services:

• Austria: lawinen.report
• Switzerland: slf.ch/lawinenbulletin
• Germany/Bavaria: lawinenwarndienst-bayern.de
• South Tyrol: lawinen.report
• France: meteofrance.com/meteo-montagne

Standard emergency equipment for ski touring consists of three components. All three are essential, with no exceptions. But beware: equipment alone will not save anyone. Only those who know how to use it have a chance in an emergency.

Avalanche transceiver

Sends and receives electromagnetic signals at 457 kHz. Everyone wears a device on their body in transmit mode. After an avalanche, searchers switch to receive mode.

• Range: 40–60 metres with modern devices
• 3 antennas have been standard since 2000
• Annual function test required
• Replace batteries regularly

Avalanche probe

A collapsible pole for pinpointing the exact location after a transceiver search. Without a probe, you are digging blindly.

• Length: minimum 2.40 m, ideally 2.80 m
• Material: aluminium or carbon
• Diameter: at least 11 mm for stability
• Markings: depth indicators every 10 cm

Avalanche shovel

A sturdy shovel with a metal blade. On average, a buried person is trapped beneath 1 tonne of snow. Without a proper shovel, you stand no chance.

• Blade: aluminium or stainless steel, never plastic
• Volume: shovel blade of at least 2.5 litres
• Shaft: telescopic or detachable
• Weight: 600–800 g for a good balance

Training is essential, not optional

Owning the equipment does not mean you know how to use it. Every second counts in an avalanche accident:

• After 15 minutes, the chance of survival drops below 50 per cent
• After 35 minutes, it falls below 20 per cent
• Professional rescue teams often take 30–60 minutes to arrive

You and your group are the first responders. An avalanche course lasts 2 days and is the most important investment you can make. You will learn:

• Fast, structured transceiver searches
• Efficient digging using strategy rather than brute force
• Probing without wasting time
• Teamwork and communication
• First aid for buried casualties

Before the tour:

• Read and understand the avalanche bulletin
• Plan your route with alternatives
• Consider the weather and temperature trend
• Check your equipment with a transceiver test
• Brief the group: who leads? Where are the critical sections?

During the tour:

• Keep your distance: in critical sections, only one person should be on the slope at a time
• Watch the slope angle: the danger starts at 30 degrees, with 35–40 degrees being the critical range
• Recognise wind slab: wind-packed snow sounds hollow and fractures in slabs
• Whumpfing sounds and cracks: turn back immediately, the snowpack is unstable
• Spacing: keep 10 m apart uphill and 30–50 m downhill
• Regrouping points: wait in safe places after key sections

Take warning signs seriously:

• Recent avalanches, including small ones
• Whumpfing sounds while walking
• Cracks forming in the snowpack
• Blowing snow plumes on ridgelines
• Rapidly rising temperatures

If you are caught in an avalanche:

1. Shout loudly so others know your last known position
2. Release your skis or board if possible to prevent lever injuries
3. Make swimming movements and try to stay on the surface
4. Create an air pocket: in the final phase, hold your hands in front of your face to make breathing space
5. Stay calm: panic uses up oxygen

If someone is buried:

1. Note the last seen point: watch exactly where the person disappeared
2. Call emergency services on 112 while searching, not before
3. Start the transceiver search: everyone switches to receive mode, then carry out a systematic signal search, coarse search, fine search and pinpoint search; use the probe once the signal is clear
4. Dig strategically: not directly from above, but in a V-shape from below
5. Give first aid: clear the airways, keep them warm and prepare for rescue

The first 15 minutes are decisive:

• 0–15 min: 90 per cent chance of survival
• 15–35 min: 30 per cent chance of survival
• 35+ min: less than 20 per cent chance of survival

You are the only realistic rescue option. Professionals arrive too late.

This knowledge is a start, but it is no substitute for practical training. An avalanche course gives you the skills that can save lives in an emergency.

What you will learn in a basic course:

• How to interpret the avalanche bulletin
• Terrain assessment: slope angle, aspect and warning signs
• Understanding snowpack structure
• Transceiver searches in realistic conditions
• Shovelling and probing techniques
• Strategic digging
• Group management and communication

Course providers:

• German Alpine Club
• Austrian Alpine Club
• Swiss Alpine Club
• Private mountain schools and mountain guides
• Ski touring providers

Cost: EUR 200–350 for 2 days, the most important investment you can make.