Strong to extreme winds and new snow have created a windslab problem. Human triggered avalanches are likely.
Spring weather can change rapidly! Have a backup plan if conditions aren't what you were expecting.
Strong Southwest winds are building windslabs in the Alpine, Treeline and below treeline in wide open valleys (like the Illecilewaet & Connaught). This problem will be most reactive in lee features and will be reactive to human triggering.
A persistent weak layer (PWL), buried March 5th, is now down 60-120cm in the snowpack. Depending on aspect and elevation, this layer may be suncrust, facets and/or surface hoar. There's potential for step-down avalanches with this layer from other avalanches or cornice fall.
A field team was able to find reactive wind-slabs up to 30cm deep, propagating 10-15m and running half-way down fans. They also observed size 1 skier triggered, dry loose avalanches running mid fan.
Natural avalanche activity has tapered off in the last few days. The majority of the action has been either solar triggered loose dry when the sun pops out or windslabs at ridge top in the alpine.
Convective squalls have incrementally delivered up to 40-60cms of new snow in the last week. Recent wind has been redistributing the storm snow.
The March 5th interface is down 50-100cm and consists of a crust &/or surface hoar.
Two persistent weak layers (PWL) of facetted snow from cold temps in Jan/Feb are now buried 120-160cm beneath the surface.
Periods of snow and flurries through the weekend.
Tonight Clear. Alpine low -9°C. Ridge wind SW 10-20km/hr
Sat Flurries. Alpine high -8°C. West ridge winds 25-45km/h. FZL 1300m.
Sun 14cm. Alpine high -4°C. SW winds 20-30km/h. FZL 1400m.
Mon Flurries. 12cm. Alpine high -3°C. SW winds 35-45km/h. FZL 1800m.
