Avalanche Forecast

Issued: Feb 1st, 2013 9:27AM

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

triley, Avalanche Canada

South Columbia.

The weather forecast says that you better put your sun screen on for Saturday! The snow pack doesn't have sun screen, so it might start peeling off if the sun gets too hot or alpine temperatures get too warm.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Saturday

Weather Forecast

Overnight and Saturday: Light Northwest winds and thin high cloud overnight with freezing down to the valleys. Light West winds with mostly clear skies with a chance of valley cloud and the freezing level rising up to about 2000 metres. A chance of an above freezing layer in the alpine during the afternoon; chance increases as you move to the South.Sunday:Freezing levels dropping and alpine temperatures moving down to about -3.0 as the cloud cover thickens in advance of the next pulse of moisture coming from the coast.Monday: West winds building during the day with light flurries becoming moderate snow by evening.

Avalanche Summary

The cycle of small natural and skier controlled avalanches continues to result in avalanches up to size 1.5 that are about 30-40 cms deep. Expect this cycle to continue with warming trend.

Snowpack Summary

The recent storm snow has been reported to be settling into a cohesive slab above the old surfaces that were buried on January 23rd. This storm slab may become reactive due to the forecast warm temperatures and strong solar radiation. Some wind slabs that have developed on Southerly exposed terrain during the recent Northwest winds may also become more reactive and fall off naturally during this forecast warm spell. Cornices that have not been exposed to any warming may not be well anchored due to recent shifting wind directions. The storm slab is about 50 cms deep in most places and is sitting on a weak layer of surface hoar and facets at treeline and below, and in some places on an old sun crust in the alpine. Some areas in the West Monashees have a layer of heavier moist snow near the surface that may be sitting on a variable freezing rain crust that is down about 20 cms.

Problems

Wind Slabs

Wind slabs that have developed on Southerly aspects during the recent Northwest winds may become more reactive with forecast solar radiation and possible above freezing temperatures in the alpine.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

Storm slabs may become more reactive with forecast solar radiation and possible above freezing temperatures in the alpine.

Avoid travelling on slopes which are becoming wet due to rain, warm temperatures, or sun.>Watch for wet loose or slab activity with forecast warm temperatures.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Cornices

Cornices may not be well anchored, and may fall off naturally due to warm alpine temperatures.

Avoid steep slopes below cornices.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Feb 2nd, 2013 2:00PM