Avalanche Forecast

Issued: Feb 15th, 2019 5:02PM

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

jfloyer, 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

FRIDAY NIGHT: Around 3 cm of low density snow expected. Mostly light winds.SATURDAY: Around 2 cm new snow. Treeline temperatures around -9C. Light northeasterly winds.SUNDAY: Dry and cloudy. Treeline temperatures around -10C. Light northeasterly winds.MONDAY: Dry, with some clear spells. Treeline temperatures around -14C. Moderate northwesterly winds.

Avalanche Summary

No avalanches were reported from this region on Thursday. 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.

Snowpack Summary

Recent strong northeasterly winds have blown loose snow into wind slabs in exposed areas.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

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.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

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.

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

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Feb 16th, 2019 2:00PM