Avalanche Forecast

Issued: Feb 1st, 2017 4:22PM

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

Avalanche Canada cam_c, Avalanche Canada

Touchy winds slabs are lurking below ridgecrests and behind terrain features. Use extra caution as you transition into wind affected terrain and watch for signs of recent wind loading.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

THURSDAY: Mainly sunny with light northeasterly winds. Freezing levels in valley bottoms with alpine temperatures reaching -15 C.FRIDAY: Increasing cloudiness with light snow flurries starting in the afternoon/evening. Light but gusty southwesterly winds and freezing levels remaining in valley bottoms with alpine temperatures reaching -10 C.SATURDAY: Cloudy with flurries bringing  5-10cm under light but gusty southwesterly winds. Freezing levels remaining in valley bottoms with alpine temperatures reaching -10 C.

Avalanche Summary

On Sunday and Monday, several natural wind slab avalanches up to size 2.5 were observed throughout the region. These avalanches occurred on most aspects and were mainly in the alpine but a few were at treeline. Slabs were typically 10-30 cm thick. Skiers also triggered several wind slab avalanches on Monday and Tuesday up to size 1.5. One of these avalanches was remotely triggered from 40 m away.Fresh wind slabs are expected to remain sensitive to human triggering, especially on steep and unsupported (convex) slopes. Winds have recently switched from south to north and wind slabs should be expected on all aspects in exposed terrain.

Snowpack Summary

Light amounts of recent snow with strong shifting winds have resulted in fresh wind slabs on a variety of aspects in exposed terrain. A sun crust is being reported on steep solar aspects. Surface faceting is also being reported as a result of the current cold temperatures. A persistent weakness buried mid January is now down 20-50 cm and consists of buried surface hoar in sheltered areas, sun crust on south aspects, and/or widespread faceted old snow. It has generally stabilized but may be sensitive to triggering in isolated areas where buried surface hoar is preserved. The mid and lower snowpack are generally well settled and stable.

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh wind slabs are expected to remain sensitive to human triggering, especially on steep and unsupported (convex) slopes. Winds have recently switched from south to north and wind slabs should be expected on all aspects in exposed terrain.
Avoid areas where the surface snow feels stiff or slabby.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 2nd, 2017 2:00PM