Wind slabs can currently be found on almost any aspect. Expect those on steep southerly slopes to be especially touchy.
Confidence
High - The weather pattern is stable
Weather Forecast
We're in warming trend with the last of the fine weather Sunday. Even warmer temperatures and rising freezing levels Monday through Wednesday. SUNDAY: Sunny with increasing clouds in the afternoon. Winds light westerly. Freezing level 1100m and alpine temperatures around -4 Celcius. MONDAY: Mix of rain and snow (10-20 cm at higher elevations) in the afternoon. Winds strong from the southwest. Freezing level 2000m and alpine high temperatures to +1 Celcius. TUESDAY: Mix of rain and snow (up to 45cm at higher elevations). Winds moderate to strong (35-70 Km/hr) from the south. Freezing level 2000 metres with alpine temperatures to 0 Celcius.
Avalanche Summary
A video of a snowboarder caught Wednesday in a Size 2 avalanche near Brandywine (Chocolate Bowl) has gone viral. See the MIN post below for more details:https://avalanche.ca/map/forecasts/sea-to-sky?panel=mountain-information-network-submissions%2F8c832980-b83c-4b4f-a23d-540ed9bfe606A Size 2.5 natural was seen on the south aspect of Mt Currie near 2100m elevation on Thursday.
Snowpack Summary
Wildly variable wind effect is the main story here. In the days since the last storm on Sunday-Monday, winds shifted to classic outflow (northerly) patterns with strong winds at ridge top for 24 hours. By and large this 'reverse loaded' snow in the alpine and also affected treeline elevations too. Touchy windslabs (5-40 cm thick) formed on southerly slopes near ridge crests and roll overs. These slabs are the primary weakness of concern in the snowpack and our colder-than-usual temperatures of late mean the upper snowpack will be slower than usual to heal. Deeper in the snowpack, the new snow from Sunday night and also last Friday is bonding fairly well to a variable surface consisting of a mix of soft wind slabs, hard wind slabs, sastrugi, faceted snow, and even some surface hoar. Snowpack layers below this interface are generally well bonded, and the lower snowpack is solid.
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.