Avalanche Forecast

Moderate - Confidence is due to a stable weather pattern with little change expected. Uncertainty is due to the limited number of field observations.

Cold arctic air will persist until Saturday afternoon. The weekend weather is looking quite wild, starting with wind on saturday, and heavy snowfall that night and through Sunday.

THURSDAY NIGHT: Clear. No new snow expected. Light to moderate northwest wind. Treeline low around -10 C.

FRIDAY: Sunny. Moderate wind from the north. Treeline low around -11 C.

SATURDAY: Overcast. 3 cm of snow expected. Strong southwest wind, trending to extreme west at higher elevations. Treeline temperature rising to around -7 C. 

SUNDAY: Overcast. 30 cm of snow expected overnight, with another 40-80 cm through the day. Extreme southwest winds. Freezing level rising to 500 m.

On Thursday, this great Mountain Information Network (MIN) post reported small natural and rider triggered avalanches in the snow that fell overnight on Wednesday. It looks like there is an instability that is reactive in steep terrain and on convex rolls, but the slab is not large or stiff enough to propagate further, it might not even be a slab, it could just be low density snow that lacks cohesion. 

If you find a feature with a deeper or stiffer slab, or above a terrain trap, this could be a bigger problem, so continually evaluate the conditions as you travel.

No new avalanches were reported on Tuesday or Wednesday.

    

Some small avalanches were reported on the North Shore mountains over the weekend. These include a few size 1 skier triggered slabs on convex rolls in the Seymour backcountry (see photos in the MIN reports here and here) and some loose dry avalanches in the top 10 cm of low density snow.

Recent, north to northwesterly outflow winds have created some windslabs in atypical cross-loading and reverse loading patterns. Recent cold temperatures have encouraged some near surface facetting, keeping the loose snow loose, and starting to soften some of the windslabs. 

These recent wind slabs or low density snow sit above a mostly settled and bonded snowpack with a few crusts in the top 100 cm. 

Higher terrain around Squamish may have a lingering weak layer of facets above a crust that formed in early December. This layer is now 150-200 cm deep and has likely transitioned from stubborn to unreactive.

• Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
• Recent new snow may be hiding windslabs that were easily visible before the snow fell.
• Approach steep, open and/or sparsely treed slopes cautiously.
• Caution around convexities or sharp changes in terrain.
• Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
• Recent wind has varied in direction so watch for wind slabs on all aspects.