Freeride Safety Guide

Graphical Reduction Method (GRM)

Typical Avalanche Situations (Patterns)

characteristics and distribution

Typical Avalanche Situations (Patterns)

The avalanche bulletin provides information about snow conditions and regional avalanche danger for all regions of the Swiss Alps (local variations are possible). The degree of avalanche danger depends on: the release probability (the natural stability of the snow cover and the effects of human activities), the distribution and frequency of dangerous slopes, the size and type of avalanches (inclu- ding the mass of released snow layers). issue avalanche bulletin (daily after 08.00 and 18.30 h) distribution:  www.slf.ch  App «White Risk» Avalanche Bulletin Northern flank  Terrain transitions (e.g. from flat to steep or from ridge to bowl)  Rocky outcrops  Often found on north facing slopes tips:  Simple snowpack tests often useful  Difficult to recognise  Pay attention to bulletin information  Use GRM defensively

 wait 1 – 3 days

New snow

Moderate, Considerable, entire slope * high, entire

release as a slab

The new snow may

slope including

deposition zone

There are weak layers in the snowpack covered with older slabs. Difficult to recognise!

Wind loading Elevated risk. Caution! Experience necessary! Patterns, weigh up pros, cons with the focus on the avalanche risk on the individual slope.  avoid 1 – 2 days

High Savoy 0033 892 681 020 (*74)

 Weak layer within the snowpack

 Alarm signs (whumpf sounds)

typical distribution:  Regions / zones with

relatively shallow snow cover

release as a slab

Recent drifts may

old snow

typical signs:

Main Alpine Ridge

Aosta Valley 0039 0165 776 300

Inneralpine Regions

Western part

Danger degree withh considered area of the slope

area of the track

Low,

Intelligent route choice and intelligent behaviour Inexperienced riders should avoid this area Training and experience necessary Low risk

Relatively safe if no particular danger signs are present Inexperienced skiers and boarders should stay below this line.

High risk Snowsport not recommended!

of the Alps

snowpack steep Terrain over 30° is potential avalanche terrain.

* If at considerable danger remote triggering or large avalanches are unlikely (often the case with constantly travelled off-piste runs/popular tours), then it may be possible that not the entire slope must be conside- red. outgoing radiation)  High temperature / strong solar radiation  Deep penetration  Natural avalanche release (slab, loose snow) Wet snow typical signs:  Rain  Overcast (reradiate

typical distribution:  Varying aspects and

altitudes (dependent on time of year / day)

 Often found near warm rocks tips:  Return early

 Wait for cooling

 Beware of large natural- ly triggered avalanches

 GRM not always appli- cable

Water weakens the If we do not know the conditions, if we can’t make obser- vations, or if the unfavourable slopes are not specified in the bulletin, we assume all slope aspects to be unfavou- rable. If there is a difference, we may assume a lower danger for the slopes of favourable aspects (typically about one degree lower).

hours

Wet, heavy snow  go early, return early

35º

30º

Piemonte 0039 011 1968 1340

steep

Weather: www.meteoswiss.ch Avalanche conditions in adjacent countries: www.lawinen.org

Central part

Gotthard

Moderate, Considerable, entire slope * high, entire

Moderately Steepest section (ca. in the proper area

Northern Alpine Ridge

Southern flank

of the Alps

slope including

deposition zone

Eastern part

South Tyrol 0039 0471 271 177 Elevated risk. Caution! Experience necessary! Patterns, weigh up pros, cons with the focus on the avalanche risk on the individual slope. Lombardia 0039 0269 666 554 Wind loading typical signs:

Inneralpine Regions

 Irregular when breaking trail  Cohesive snow

 Signs of snow drifting

 May be hard packed or soft

 Alarm signs (e.g. recent slab avalanches, cracking)

 Wind shadows (leeside, terrain breaks, gullies)

 Often found at high alti- tude and ridge areas

 Variation within a small area tips:

 Avoid when possible

 Recent snow drifts are often dangerous over 30° of slope angle

 GRM not always appli- cable

Bavaria 0049 89 9214 1510 typical distribution:

days or weeks

Old snow  ride defensively

Vorarlberg 0043 5574 201 1588

Tyrol 0043 512 508 802255

Danger degree withh considered area of the slope

area of the track

Low,

Intelligent route choice and intelligent behaviour Inexperienced riders should avoid this area Training and experience necessary Low risk

Relatively safe if no particular danger signs are present Inexperienced skiers and boarders should stay below this line.

High risk Snowsport not recommended!

steep Terrain over 30° is potential avalanche terrain.

40º

35º

30º

very

steep

extremely steep

steep

Simple risk check combining the factors of danger level, slope angle and aspect (favorable/unfavorable). Dangerous expositions are often:  Shady slopes  Wind loaded slopes

 Expositions and altitudes specifically mentioned in the avalanche bulletin.

 Critical new snow depth  Alarm signs (e.g. recent slab avalanches)

 Dangerous areas cover a wide area

 Danger often increases with altitude tips:

 Few avoidance possibilities

 GRM useful

Steepest section (ca. 20 m x 20 m) in the proper area of the slope

Avalanche risk in unfavorable aspects: Moderately

new snow

Mod Steepest section (ca. 20 m x 20 m) typical signs:

typical distribution:

10

11

 G

 Fe

tip

 D

 D

typ

 A

 C

typ

ne

G

 E

 W

 S

Da

slo

Sim

Av

ex

p

w

w

sl

a