Avalanche Forecast

Issued: Apr 16th, 2012 10:13AM

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

mbender, Avalanche Canada

Sea To Sky.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Weather Forecast

TUESDAY: Overcast with sunny breaks and the possibility of very light precipitation. Light southerly winds and 1200m freezing level. WEDNESDAY: Light precipitation possible throughout the day with a weak ridge of high pressure bringing drier conditions in the PM. Winds moderate from the southwest and 1200-1500m freezing levels. THURSDAY: Mostly drier conditions. Freezing levels 1200-1500m.

Avalanche Summary

Recent observations include cornice falls (size 1-2) and glide slab releases to size 3.5. Loose moist avalanches have been observed during periods of warming.

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 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 - Likely

Expected Size

1 - 4

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 - 6

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 - 4

Valid until: Apr 17th, 2012 9:00AM