Avalanche Forecast

Saturday night: 5 cm new snow in the south of the region, a trace elsewhere. Moderate northwest wind. Treeline temperatures around -10.

Sunday: Mainly sunny, isolated flurries. Light to moderate northwest wind. Treeline high temperatures around -12.

Monday: Snow 10-15 cm in the south of the region, a trace elsewhere. Light northwest wind. Treeline high temperatures around -12.

Tuesday: Mainly sunny. Moderate southwest wind building to strong. Treeline high temperatures around -7.

Wind slab was reactive to explosives in the Hurley on Thursday. Reports from explosive control work in the Duffey Lake area Wednesday showed debris from releases up to size 2 (large) scouring to ground in tracks and reaching quite low in runouts. This followed the widespread natural avalanche cycle up to size 3.5 (very large) that occurred over Tuesday night. These sizes suggest that some avalanches may have involved persistent layers discussed in the snowpack summary.

A trace to 15 cm of new snow may sit over a widespread layer of small surface hoar crystals which we will continue to monitor going forward. Dry, wind affected snow can be found in the high alpine. Below 2100 meters, wind-affected snow overlies a thick crust. Below 1800 m a thick, supportive crust caps the snowpack, effectively locking it in place at lower elevations.

A couple of buried weak layers produced large avalanches during a previous storm. Snowpack models and observations in the neighboring Sea to Sky region indicate that these layers have been reset by recent rain at treeline, but uncertainty remains around their status in the alpine. These include a layer of surface hoar down an estimated 90-120 cm and deeper crust/facet combo layer.

Average snowpack depths in the alpine are now likely closer to 150-200 cm. Below treeline, depths of 30-50 cm have been reported around 500 m, decreasing dramatically with elevation, and still below threshold for avalanches in many areas. Early season hazards such as rocks, stumps, and creeks are still a concern below the alpine.

• Closely monitor how the new snow is bonding to the crust.
• Keep in mind the crust offers an excellent bed surface for avalanches.
• Dial back your terrain choices if you are seeing more than 20 cm of new snow.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.