Avalanche Forecast

Issued: Apr 17th, 2012 10:44AM

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

mbender, Avalanche Canada

Sea To Sky.

Summary

Confidence

Good - Timing, track, or intensity of incoming weather is uncertain on Friday

Weather Forecast

WEDNESDAY: Light precipitation throughout the day. Moderate southwesterly winds and 1100m freezing level. THURSDAY: Little to no precipitation throughout the day. Moderate to heavy precipitation starting in the afternoon combined with moderate southerly winds. Freezing level 1200-1500m. FRIDAY: Light to moderate precipitation throughout the day. Freezing levels 1200m.

Avalanche Summary

Recent observations include cornice falls (size 1-2). Loose moist avalanches have been observed during periods of warming along with thin windslabs (10cm deep) above releasing to size 1 above 2100m.

Snowpack Summary

A generally strong and deep spring snowpack exists. At this time of year, snowpack stability tends to decrease during times of warming (e.g. on slopes receiving sunshine, during rainfall, in the afternoon and at low elevations) and improve when the surface freezes. Conditions may be quite icy in the morning. A crust layer from late March, buried within the upper 2 m of the snowpack, remains a lingering concern, although the snowpack above it is settling and strengthening. Large cornices threaten slopes and glide slab releases are a possibility, especially in steep rocky terrain.

Problems

Wind Slabs

Wind slabs may may continue to develop with incoming snow and wind. Be alert for these behind ridges and terrain breaks.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

Wet loose or slab avalanches are most likely at times when temperatures are warm, e.g. on slopes receiving sunshine, during rainfall, in the afternoon and at low elevations. Avoid exposure to slopes which are sporting glide cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Cornices

Large cornices are looming. These are a hazard in themselves and could trigger avalanches on the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Apr 18th, 2012 9:00AM