Avalanche Forecast

Issued: Feb 2nd, 2017 4:08PM

The alpine rating is moderate, the treeline rating is moderate, 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

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 -15 C.SUNDAY: Cloudy with flurries bringing 3-5 cm under light but gusty southwesterly winds. Freezing levels remaining in valley bottoms with alpine temperatures reaching -15 C.

Avalanche Summary

On Sunday and Monday, several natural wind slab avalanches up to size 2.5 were observed throughout the region, some triggered by cornice falls. These avalanches occurred on most aspects and were mainly in the alpine but a few were at treeline. Slabs were typically 20-30 cm thick. On Tuesday, three separate cornice failures triggered Size 2-2.5 wind slabs on the slope below, one stepped down to a deep persistent weakness near the ground. Skiers and sledders have also triggered several wind slab avalanches this week up to size 1.5. Fresh wind slabs are expected to remain sensitive to light triggers, especially on steep and unsupported (convex) slopes.In the far north of the region around Blue River and Valemount, a persistent slab problem still exists. Several large human triggered avalanches were reported last week. Click here for more details.

Snowpack Summary

Up to 15 cm of recent snow with strong shifting winds have resulted in fresh wind slabs on a variety of aspects in wind exposed terrain. A sun crust is being reported on steep solar aspects and surface hoar is growing on sheltered open slopes. Surface faceting is also being reported as a result of the current cold temperatures. A persistent weakness buried mid January is now down 30-50 cm and consists of buried surface hoar in sheltered areas, 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.Another surface hoar/facet persistent weakness was buried mid-December and can now be found down 100-120 cm. It has become inactive in the south of the region, but may still be sensitive to triggers in the northern part of the region near Blue River and Valemount. It is highly recommended to investigate this layer before committing to any large, unsupported features. Read the Cariboo forecast for more information.

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.
Use caution in lee areas. Recent wind loading has created wind slabs.Avoid areas where the surface snow feels stiff or slabby.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 3rd, 2017 2:00PM

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