Avalanche Forecast

Issued: Nov 26th, 2012 9:47AM

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

jlammers, Avalanche Canada

Cariboos.

Summary

Confidence

Poor - Due to limited field observations

Weather Forecast

Tuesday: Mostly clear skies / Moderate to strong northwesterly winds / Freezing level at 1200mWednesday: Increasing cloud throughout the day with light snowfall developing by the evening / Strong southwest winds / Freezing level at 1300mThursday: Moderate snowfall / Strong southwest winds / Freezing level at 1400m

Avalanche Summary

A size 2 sled-triggered slab avalanche occurred on Sunday in the Yanks Peak area. It was on a northwest aspect at 1900m. For more details, check-out our Incident Data Base.

Snowpack Summary

Healthy amounts of snow fell throughout last week. Although alpine wind data has been sparse, velocities in neighboring regions have been in the upper end of moderate. That said, I'd be highly curious about the possibility of windslabs in exposed areas. Although storm slab reactivity is still possible, a break in the snowfall over the last few days has most likely given the upper snowpack a chance to settle and gain some strength. There may be a thin buried surface hoar layer down about 85 cm in the alpine. As well, the November rain crust now exists over 100cm down in some locations and may exist in combination with facets. This layer has shown sudden planar test results.

Problems

Storm Slabs

Although last week's snow has had time to gain some strength, triggering storm/wind slabs is still possible, particularly in steep, unsupported terrain.

If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.>Avoid travelling in areas that have been reverse loaded by winds.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

There is a variable crust that exists in the lower snowpack. Watch for triggering on unsupported terrain at higher elevations or within start zones with smooth ground cover.

Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Nov 27th, 2012 2:00PM