Recent precipitation fell as snow at higher elevations and a mix of snow and rain at lower elevations. Observe for signs of instability, such as cracking, whumpfing, and avalanche activity -- each elevation band will be different.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
FRIDAY: Early-morning sunshine and afternoon clouds, light easterly winds, alpine temperature -4 C, freezing level rising to 2000 m.SATURDAY: Cloudy with snowfall, accumulation 5 to 10 cm, light northeasterly winds, alpine temperature -7 C, freezing level 1500 m.SUNDAY: Cloudy with light snowfall, accumulation 5 to 10 cm, light easterly winds, alpine temperature -9 C, freezing level 1200 m.
Avalanche Summary
Loose wet avalanches were reactive to skier traffic below treeline on Thursday.
Snowpack Summary
Around 15 to 25 mm of water equivalent fell in the region on Thursday. This would have fallen as snow at higher elevations (likely up to 25 cm of snow) and partially as rain at low elevations. This precipitation fell on a thick melt-freeze crust that exists on all aspects from recent warm temperatures and rain, except for possibly higher elevations on north aspects. The upper snowpack may still be wet at low elevations.A weak layer of surface hoar buried mid-February exists in parts of the region around 50 to 80 cm deep. The lower snowpack is weak with a combination of crusts and facets near the bottom of the snowpack that are widespread.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.