Avalanche Forecast

Issued: Nov 23rd, 2013 7:39AM

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

swerner, Avalanche Canada

Cariboos.

Forecasts are based on very limited observations. Dig down, test weak layers and keep an eye on rising temperatures Monday.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

High pressure will strengthen though the forecast period. This will slowly bring warmer temperatures to upper elevations and no significant precipitation is expected.Sunday: A mix of sun and cloud. Alpine temperatures -4. Freezing levels 1600 m. Ridgetop winds from the NW. Monday/Tuesday: Cloudy with some sunny periods. Alpine temperatures near 0 degrees. Freezing levels rising to 2500m. Ridgetop winds will be light from the South.

Avalanche Summary

Last weeks storm, triggered a widespread natural avalanche cycle in the alpine. Size 2-3 slab avalanches were reported throughout the region. Recently no new avalanches have been reported. However, isolated large slab avalanches may still be rider triggered, especially on slopes that didn't previously avalanche.

Snowpack Summary

Average snowpack depths at upper elevations sit near a metre or more. Recent storm snow seems to be settling, but wind slab problems likely exist.A surface hoar layer may exist 60-120 cm down but seems to be spotty, and drainage specific. Have you seen any?A bigger concern is a melt-freeze / rain crust that formed early October. This is generally found from 80-180 cm down near the base of the snowpack. On northerly aspects a more predominant crust/ facet combo may exist and allow for wider propagations. especially in places that have smooth ground cover (glacier ice, grassy slopes, rock slabs etc.).Snowpack conditions may change and deteriorate as temperatures rise in the alpine.

Problems

Persistent Slabs

Last week, large avalanches failed on a buried crust/facet combo near the base of the snowpack. Rider triggers may be possible, especially on northerly slopes in alpine terrain that did not previously avalanche.

Be aware of the potential for large, deep avalanches due to the presence of buried crust.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 5

Wind Slabs

Recent wind has hammered alpine areas. Wind slabs are most likely found on lee slopes and behind terrain features.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.>

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Nov 24th, 2013 2:00PM