Alpes du Sud
Ubaye
Avalanche Problems
Persistent weak layers + No distinct problem
1
Field notes
Persistent weak layers
Persistent Snowpack layer in which the crystals are poorly bonded and the layer has the potential to fail. Typical crystals in dry weak layers causing avalanches are : precipitation particles; surface hoar; faceted crystals; hollow crystals; graupel. Generally >1mm in size, loose grains with few bonds Wet weak layers can be formed by all snow crystal/grain types.EAWS glossary are very challenging to recognise. 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 and shooting cracks are typical when present, but you can have a serious weak layer with no warning signs at the surface. Knowledge of how the Snow deposited on the ground in a multiplicity of layers.EAWS glossary has evolved is essential. SLF's travel advice is direct: travel conservatively, avoid terrain where the consequences of being caught are large, and treat the history of weather and snow as more important than what you can see today. Read the full bulletin.
No distinct problem
SLF uses this label when no single problem dominates the assessment, often on lower-danger days. It doesn't mean conditions are safe: any avalanche type is still possible, and normal caution applies. On stable days this is usually a signal to enjoy the mountains with general awareness; on less-stable days where the assessment is still inconclusive, it's a signal to be cautious specifically because there's no clear pattern to follow.
Avalanche Activity
RARES PETITES INSTABILITÉS À HAUTE ALTITUDE - MANTEAU NEIGEUX PEU ÉPAIS ET BIEN STABILISÉ DANS L'ENSEMBLE
peu probables.
dans un large secteur nord au-dessus de 2600/2700 m, rares plaques résiduelles reposant sur des couches fragiles persistantes, derrière les hautes
crêtes ou ruptures de pente, là où le vent a accumulé un peu de neige ces derniers jours.
Le déclenchement de ces instabilités est difficile et engendre seulement de petites avalanches (taille 1), mais elles peuvent déstabiliser un pratiquant dans une pente raide.
Outlook
Constant avalanche danger
Snowpack & Weather
Snowpack
Situation avalancheuse typique
couche fragile persistante
Déclenchements provoqués : dans un large secteur nord au-dessus de 2600/2700 m, rares plaques résiduelles reposant sur des couches fragiles persistantes, derrière les hautes
crêtes ou ruptures de pente, là où le vent a accumulé un peu de neige ces derniers jours.
Le déclenchement de ces instabilités est difficile et engendre seulement de petites avalanches (taille 1), mais elles peuvent déstabiliser un pratiquant dans une pente raide.
Départs spontanés : peu probables.
Outlook
Tendance du mardi 11 novembre
Indice de risque faible
aintien d'un risque faible, en l'absence de
ouvelles chutes de neige.