Avalanche Forecast

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Monday night: Dry with clear skies. Cooling temperatures.

Tuesday: 5-10 cm new snow. Freezing level around 600 m. Winds light to moderate southwesterly.

Wednesday: 15-20 cm new snow. Freezing level around 800 m. Winds moderate southerly. 

Thursday: Flurries. Freezing level around 900 m. Winds light southwesterly.

A large (size 2.5) avalanche was triggered on Monday by a snowmobiler on Rainbow mountain in alpine terrain, which resulted in a full burial and, thankfully, a successful rescue. The avalanche failed on a layer 60 cm deep. At this time the nature of the failure plane is unknown, but it is reasonable to assume it failed on one of the two weak layers discussed in the snowpack section. This avalanche points to the ongoing potential to trigger persistent weak layers in the snowpack.

A small (size 1) avalanche was also triggered on Monday by skiers on a north aspect in the Whistler backcountry, most likely in recent storm snow.

15-30 cm of recent snow has been redistributed by strong south to east winds, depositing deep pockets of storm slab into lee terrain features.

Two potential concerning weak layers may be present in the snowpack: 

• The shallower layer, around 60 to 100 cm deep, includes feathery surface hoar crystals. This layer may be found in sheltered terrain features at treeline and lower alpine elevations but has been reported as spotty across the region. 
• The more widespread weak layer includes sugary faceted grains that overlies a hard melt-freeze crust. This layer ranges in depth from 10 cm to 120 cm due to the wind scouring and loading the snow in different terrain features over the past two weeks. The layer has been reported as being widespread up to around 2000 to 2200 m. 

To date we have mostly seen sporadic avalanche activity on these layers, but they remain possible to trigger where they exist in the mountains.

The remainder of the snowpack is well-settled.

• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Conditions may have improved, but be mindful that deep instabilities are still present.
• Surface hoar distribution is highly variable. Avoid generalizing your observations.