Avalanche Forecast

Issued: Jan 29th, 2013 9:19AM

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

swerner, Avalanche Canada

South Coast.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday: Moist NW flow continues to bring unsettled conditions to the region. Snow amounts up near 10 cm. Ridgetop winds moderate from the NW. Alpine temperatures near -2.0 and freezing levels around 1500 m. Thursday: Mainly cloudy with possible sunny periods in the afternoon. Flurries accompanied by moderate ridgetop winds from the West. Alpine temperatures near -3.0 and freezing levels rise to 1700 m.Friday: Cloudy with dryer conditions. Some flurries with ridgetop winds light from the SW. Alpine temperatures -4.0 and freezing levels around 1600 m.

Avalanche Summary

Natural sluffing from steep terrain features.

Snowpack Summary

Up to 30 cm of snow fell over the past few days with light to moderate winds. This snow seems to be settling and gaining strength although lingering wind slabs are possible behind ridges and ribs. Wind slabs may be found in unsuspecting places due to changing winds from SW-NW. Be cautious of cross-loaded terrain features. The new snow has also buried a variety of surfaces including old wind slabs, crusts and large surface hoar crystals which can be found in sheltered terrain below treeline. The most recent buried crust/surface hoar down approx. 10-30 cm are producing moderate-sudden planar and resistant test results, and should remain a layer to watch. Down deeper sits another surface hoar layer (40-80 cm) which seems to be gaining strength.Near the base of the snowpack, a crust/facet layer exists, which is now unlikely to be triggered, except perhaps by heavy triggers in unsupported, shallow, rocky terrain where more faceting has taken place.

Problems

Wind Slabs

New snow has been blown behind ridges and ribs with switching SW-NW winds. This is a less typical pattern so east and south facing slopes as well as cross-loaded features are more suspect especially in areas where buried weaknesses may exist.

Avoid freshly wind loaded features.>Use extra caution with lee and cross-loaded terrain near ridge crests.>Dig down to find and test weak layers before committing to a line.>Be cautious of sluffing in steep terrain; especially where terrain traps exist below.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Jan 30th, 2013 2:00PM