Avalanche Forecast

Issued: Apr 11th, 2015 8:26AM

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

bcorrigan, Avalanche Canada

Sea To Sky.

Use caution in wind loaded terrain and on big features.

Summary

Confidence

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

Weather Forecast

SUNDAY: Cloudy with flurries, 5 cm of snow, freezing level at 1000m, strong westerly winds.MONDAY: Cloudy with flurries,10 to 15cm of snow, freezing level around 1200m, and winds moderate from the South.TUESDAY: A break in the weather, cloudy with sunny periods, freezing level may go to 1200m, wind from the South West.

Avalanche Summary

No reports of avalanche activity in the Sea to Sky region, (yet..), probably because the storm is just beginning. Expect wind slab activity and cornice failures with the current weather pattern and increased loading. Solar aspects will be come active when the sun comes out.

Snowpack Summary

20cm of recent precipitation on a variety of crusts and old surfaces. Surface hoar and facets in sheltered locations from the recent clear weather. Moderate to strong south west winds will redistribute the storm snow into wind slabs on the lee sides of ridge tops. A facet/crust layer buried in mid-March has been producing hard and sudden results in snowpack tests. This remains a concern in the region due to it's potential to produce very large avalanches. Cornices are also a concern these days. A cornice failure may trigger a large destructive avalanche.

Problems

Wind Slabs

15 to 20cm new snow with strong winds will build slabs on lee features. In some locations these slabs sit on facets and surface hoar from the last clear period and may be quite touchy

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>Avoid freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

We haven't had much activity on this slab-over-weak layer recently, but it's worth remembering.

Be aware of the potential for large, deep avalanches due to the presence of a buried crust/facet layer.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Cornices

New snow loading will make some cornice features quite fragile.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 12th, 2015 2:00PM