Avalanche Forecast

Issued: Mar 8th, 2013 8:49AM

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

triley, Avalanche Canada

Cariboos.

Summary

Confidence

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

Weather Forecast

Overnight and Saturday: Mostly sunny with light to moderate Northwest winds and freezing level rising to about 1300 metres. The ridge of high pressure is expected to flatten out Saturday afternoon allowing cloud and light precipitation to move into the region by Sunday morning.Sunday: Expect 5-10 cms of new snow starting early in the morning, combined with light to moderate West winds.Monday: Unsettled weather is forecast for Monday with cloudy skies and light West winds. Models are not in agreement for Monday. Hopefully we will know more tomorrow.

Avalanche Summary

A natural cornice fall triggered a slab avalanche size 3.0 on a Northwest aspect in the alpine. Some areas reported loose moist snow avalanches up to size 1.0 in the afternoon.

Snowpack Summary

Sun crusts have developed on most solar exposed aspects. Surface hoar and surface facets are growing in most areas, and there is not much wind to disturb the new growth. The recent storm snow is settling, but storm slab releases are still possible. The weak layer of surface hoar that was buried around February 12th may be triggered by storm snow avalanches in motion, or by cornice fall and other large triggers. The strong solar radiation may trigger some cornice fall or release moist loose snow in steep terrain that may step down to one of the deeper weak layers.

Problems

Persistent Slabs

There is a weak layer of surface hoar buried down about 100-150 cms (February 12th layer) that may continue to be triggered by large forces like cornice fall or storm snow avalanches in motion.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Cornices

Recent cornice growth may not be well bonded and may fall off naturally during periods of strong solar radiation.

Extra caution needed around cornices with current conditions.>Pay attention to overhead hazards like cornices.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Wind Slabs

Wind slabs that were created during or after the last storm continue to be sensitive to human triggers.

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, South.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Mar 9th, 2013 2:00PM