Avalanche Forecast

Issued: Feb 24th, 2016 8:23AM

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

pgoddard, Avalanche Canada

Sea To Sky.

Avoid travelling on or under any slopes getting the heat of the sun.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Thursday is expected to be cloudy and dry, with light southerly winds and the freezing level around 1800 m. On Friday, light snow begins in the afternoon, becoming moderate overnight and easing on Saturday (15-25 cm total). The freezing level is expected to fall towards 1400 m with this snow. Winds are light to moderate from the S-SW.

Avalanche Summary

Explosives-triggered cornice fall produced some large (size 2-3) avalanches yesterday. A few wind slabs were also triggered by skiers and naturally. In some areas affected by the sun, loose wet avalanches were observed.

Snowpack Summary

Cornices are large and weak. Recently formed storm slabs and wind slabs are generally settling, but may still be reactive to human triggers in specific terrain, and may be triggered by cornice fall. Slopes that receive direct sun are likely to develop a sun crust overnight and become moist and weak by day. Several crusts can be found in the upper metre of the snowpack. A layer of surface hoar buried in early January is down 1-2 m. In most places it is thought to be capped by a thick strong crust. It is becoming increasingly hard to make this layer fail in snowpack tests and triggering an avalanche on it is unlikely.

Problems

Cornices

Large cornices are looming. These could fail under the weight of a person, or on their own. A cornice fall can also trigger a large avalanche on the slope below.

Avoid steep slopes below cornices.>Give cornices a wide berth when travelling on ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 5

Wind Slabs

Wind slabs exist on many slopes. It may still be possible to trigger these with the weight of a person or snowmobile.

Avoid wind loaded features by travelling on ridges and ribs.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Loose Wet

Any slopes receiving direct sun may weaken and start to spill loose wet avalanches.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 25th, 2016 2:00PM