Forecast snowfall amounts are uncertain. If it snows heavily, danger may reach HIGH. A Special Public Avalanche Warning has been issued for this region.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
On Sunday, expect moderate snow (5-15 cm) and strong SW winds. Snow eases to light amounts on Monday, then the next pulse begins on Monday night , bringing around 5-20 cm snow with moderate to strong SW to NW winds. Freezing levels are between 1800 m and 2000 m, dropping on Tuesday to around 1500 m.
Avalanche Summary
A natural avalanche cycle to size 2.5 was observed on Friday. These were slabs 60-100 cm deep on north aspects, and loose wet avalanches on all aspects.
Snowpack Summary
On Friday, the snow surface became moist to 2800 m in the south, and 2200 m in the north. A few cm of snow may now overlie this moist or refrozen surface, redistributed by SW winds. The mid-March crust is down 60-100 cm and has a poor bond with storm snow above in some locations. A deeper crust/facet layer from mid-February is the one to watch: it is down 80-120 cm and continues producing very large and destructive avalanches.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.