Alpes du Nord
Belledonne
Day Risk Profile
Avalanche Problems
New snow + Wind slab
4
Field notes
New snow
Easy to spot - the snow is fresh. Look at recent avalanche activity in similar terrain, and pay attention to how much new snow has fallen in the last three days. Critical loading depends on temperature, wind, and what was on the surface before the storm. SLF advises waiting until the Snow deposited on the ground in a multiplicity of layers.EAWS glossary has had time to bond before committing to steep terrain in fresh snow.
Wind slab
Look for fresh snow deposits on Slope facing downwind/ wind sheltered aspect. Snow deposits can attain several times average snow depth.EAWS glossary, in Usually a steep, elongated, eroded trench; typically prone to snowdrift accumulation.EAWS glossary and Rounded or elongated concavity; typically tending to accumulate snowdrift.EAWS glossary, and behind ridgelines and abrupt changes in terrain — these are where the wind has loaded the snow into slabs that are easy to trigger. Recent avalanches, shooting cracks under your weight, and Distinctive noise (resembling a “whumpf” sound) occurring when a weak layer beneath a slab collapses. The air of the weak layer is forced outside the snowpack, with the resulting whumpf sound being heard. The sound usually indicates an unstable situation and can be accompanied by surface cracking. A whumpf is a clear avalanche alert.EAWS glossary sounds are clear confirmations of the problem. The safest move is to avoid wind-loaded terrain entirely. NB wind signs alone don't always mean an avalanche problem exists, and the age of drifted snow is hard to judge.
Avalanche Activity
FORTE INSTABILITÉ DU MANTEAU NEIGEUX EN ALTITUDE.
Coulées au soleil + possibles avalanches de glissement.
2000m O E
3
Faciles et souvent de grande ampleur.
S
Indices de risque : 5 très fort - 4 fort - 3 marqué - 2 limité - 1 faible -- En noir : les pentes les plus dangereuses
Stabilité du manteau neigeux
Situation avalancheuse typique : neige fraîche neige ventée
Les dernières chutes de neige ont été de l'ordre de 40/50 cm, s'ajoutant à des cumuls déjà importants depuis plusieurs jours. Un vent de nord soutenu entraîne le transport de
grosses quantités de neige meuble en altitude.
Outlook
Constant avalanche danger
Snowpack & Weather
Snowpack
EN ALTITUDE.
N Au-dessus de 2000m indice de risque fort, plus bas indice marqué.
4
Départs spontanés : Coulées au soleil + possibles avalanches de glissement.
2000m O E
3
Déclenchements provoqués : Faciles et souvent de grande ampleur.
S
Indices de risque : 5 très fort - 4 fort - 3 marqué - 2 limité - 1 faible -- En noir : les pentes les plus dangereuses
Stabilité du manteau neigeux
Outlook
km/h 60 km/h 60 km/h
Tendance du dimanche 22 février
Indice de risque marqué
fort redoux attendu dimanche pourrait
stabiliser les pentes ensoleillées, jusqu'à
s altitudes plus élevées que samedi. Dans
s versants à l'ombre, l'instabilité du
anteau neigeux restera encore très
ésente.