Avalanche Forecast

Issued: Feb 14th, 2019 5:10PM

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

mbender, Avalanche Canada

Cariboos.

The likelihood of triggering a persistent slab has reduced, however the consequence of doing so would be significant.

Summary

Confidence

High -

Weather Forecast

THURSDAY Night: Mainly cloudy with isolated flurries, light to moderate southeast wind, alpine temperature -10 C.FRIDAY: Scattered flurries, accumulation 5 cm , light to moderate southwest wind, alpine temperature -8 CSATURDAY: Mainly cloudy with isolated flurries, light north wind, alpine temperature -12 CSUNDAY: Mix of sun and cloud, light to moderate northeast wind, alpine temperature -15 C

Avalanche Summary

On Wednesday there was a report of a skier triggered size 1.5 wind slab avalanche on a north east aspect at 2200 m. On Tuesday there was report of a skier triggered size 2 persistent slab avalanche 60 cm deep on an east aspect at 1900m. On Sunday there was a small human-triggered avalanche was reported from a north aspect at 2100 m. It failed around 35 cm deep on the mid-January surface hoar layer.

Snowpack Summary

A touchy weak layer responsible for a several close calls and surprise avalanches lies approximately 50 cm below the surface (30 cm in shallow areas, 60 cm or more in deeper spots). This weak layer was buried mid-January and comprises a mix of surface hoar and facets. On southerly aspects, it lies on top of a sun crust. It is shallow enough to be easily triggered but deep enough to produce large avalanches. It is most prevalent at treeline and below, but there have been a few reports of its presence in sheltered areas in the alpine.Average snow depths are approximately 270 cm. Lower layers in the snowpack are not a significant factor at this time.

Problems

Persistent Slabs

Approximately 50 cm of snow sits above a persistent weak layer of surface hoar and crust that was buried in mid-January. This layer continues to be reactive to human triggering.

Avoid convexities as well as steep, open and/or sparsely treed slopes at and below treeline.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Wind Slabs

Many locations have been hit hard by winds over the last week forming wind slabs in the lee of terrain features on a variety of aspects. There is potential for a wind slab avalanche to step-down to a persistent weak layer below.

If triggered, wind slabs may step down to deeper layers and result in even larger avalanches.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 15th, 2019 2:00PM