Regions
Northwest Inland.
Danger will ramp up over the next few days with new snow, strong winds, and warming temperatures in the forecast. Stick to sheltered supported terrain.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
SATURDAY: Flurries starting in the morning with 3-5 cm of new snow, 20-40 km/h southeast winds, alpine temperatures around -15 C.SUNDAY: Stormy with 5-10 cm of new snow, 40-60 km/h southwest winds, alpine temperatures climbing to -5 C.MONDAY: Another 5-15 cm of snow, 60-80 km/h southwest winds, alpine temperatures around -2 C and freezing levels climb to 1200 m.
Avalanche Summary
No new avalanches were reported in the southern part of the region on Thursday. A few size 2.5 natural wind slabs were reported around Ningunsaw.Wind slab activity will likely increase over the weekend with new snow and strong winds. Warming temperatures next week will likely stress deep persistent slabs.
Snowpack Summary
Generally light daily amounts of low density snow have fallen in recent days. Strong and variable winds have likely formed wind slabs in exposed terrain. These daily accumulations have incrementally loaded a weak interface which was buried in February. This buried layer includes stiff wind slabs, facets, crusts and surface hoar. The overlying slab may have a poor bond to these interfaces, especially in areas where the slab may be stiffer and more cohesive due to winds. At treeline, the average snowpack depths are 120-190 cm and a well consolidated mid-pack of approximately up to 100 cm sits above weak basal facets (sugary snow) near the ground. The deeper basal weakness remain a concern, especially in thin rocky start zones and shallow snowpack locations.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
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.