Avalanche Forecast

Low - Uncertainty is due to extremely variable snowpack conditions reported through the region.

SATURDAY NIGHT: Mostly cloudy with isolated flurries. West-northwest wind, 25-45 km/hr. Alpine low temperature -15 C. Freezing level valley bottom. 

SUNDAY: Mix of sun and cloud. Northwest-west wind, 20-30 km/hr. Alpine high temperature -7 C. Freezing level valley bottom. 

MONDAY: Partly cloudy with isolated flurries and sunny breaks. Variable wind 10-20 km/hr. Alpine high temperature -9 C. Freezing level valley bottom. 

TUESDAY: Mix of sun and cloud. Southwest wind 10-15 km/hr. Alpine high temperature -12 C. Freezing level valley bottom.

Two MIN reports (MIN 1 and MIN 2) on Friday, Dec 3 from Quartz Creek report a deep persistent avalanche failing at the base of the snowpack sometime in the middle of the day. While its unknown if the images MIN 2 cover the same rider-triggered avalanche avalanche reported in MIN 1, they certainly highlight weak and reactive snow at the base of the snowpack.

On Thursday, Dec 2 evidence of a natural avalanche cycle to size 3 occurring overnight Wed-Thurs was observed around the Golden area and north end of the forecast region. Through the day (and throughout the region), large storm slabs (size 2) and large deep persistent slabs (size 2-2.5) were triggered by explosives.

On Wednesday, Dec 1 a natural avalanche cycle was observed near Golden, including storm slabs and cornice failures to size 2 in north facing terrain. Explosive control work also produced several storm slabs. Nearby Glacier National Park observed a widespread natural avalanche cycle and produced up to size 3.5 avalanches with explosive control methods. 

Of note, several recent avalanches in the Toby Creek drainage are thought to have failed on a late November surface hoar layer. This is believed to be lurking around the Toby Creek drainage area, however data is sparse this early in the season and this layer may extend to other areas.

5-30 cm low density snow sits over a supportive crust at upper elevations. Below 1900 m the snow surface turns into a solid crust.

Around the Toby Creek drainage, a surface hoar layer sits down 30 to 60 cm in sheltered features at treeline and below. In a snowpack test on Friday, Dec 1 this layer was observed down 50 cm and showed propagation propensity. We have limited knowledge of the distribution of this layer, but suspect is its most active between 1900-2400 m.  

A late October facet/crust layer of concern sits at the bottom of the snowpack above 1900m. This layer has been recently reactive to skiers, explosives and reactive in snowpack tests, and will likely continue to be a layer of concern.

Average snowpack depth at treeline is 100-180cm, with the deepest snowpack found near the Bugaboos. 

• Be alert to conditions that change with elevation and wind exposure.
• Carefully monitor the bond between the new snow and old surface.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
• In times of uncertainty conservative terrain choices are our best defense.