Avalanche Forecast

Issued: Feb 16th, 2017 4:20PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs and Wind Slabs.

cam_c, Avalanche Canada

Cariboos.

Be aware of conditions that change with elevation and expect touchy fresh wind slabs at higher elevations.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

FRIDAY: Unsettled conditions with isolated flurries, moderate becoming light southwesterly winds and freezing levels dropping to 1300 m.SATURDAY: Cloudy with light flurries continuing overnight, light winds and freezing levels around 800 m.SUNDAY: Cloudy with light flurries, light southerly winds and freezing levels around 1000 m.

Avalanche Summary

Reports from Wednesday and Thursday morning are limited, but include one recent natural Size 3 on a north aspect. Over the weekend, several rider triggered avalanches were reported on the MIN including a size 3 that resulted in a full burial. Click here more details (1). (2), and (3). Touchy new wind slabs are likely sensitive to light triggers and have the potential to step down and trigger persistent slab avalanches.

Snowpack Summary

Expect to find 10-15 cm of fresh snow blown into touchy wind slabs at higher elevations, and wet and cohesionless rain-soaked snow at lower elevations, which should soon freeze into a solid crust. Rapidly settling storm snow from last week is still bonding poorly to the previous snow surface from early February, which is now down 40-70 cm and includes a sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. The persistent weakness buried mid-January is now down around 80-100 cm and the surface hoar/facet weakness buried mid-December is down 100-150 cm. These deep persistent weaknesses have the potential to wake up and become reactive with the current warm temperatures.

Problems

Persistent Slabs

A persistent weakness down 40-70 cm remains remains sensitive to light triggers in isolated areas. Smaller avalanches have the potential to step down to this and deeper persistent weakness resulting very large avalanches.

Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.Whumpfing, shooting cracks and recent avalanches are all strong indicators of unstable snowpack.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Wind Slabs

Touchy fresh wind slabs are likely lurking below ridgecrests and behind terrain features at higher elevations.

Avoid recently wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 17th, 2017 2:00PM