Avalanche Forecast

Issued: Apr 4th, 2015 9:14AM

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

bcorrigan, Avalanche Canada

Sea To Sky.

Hazard may change to higher than forecast with daytime warming on solar aspects. Cornices should be regarded with respect and suspicion.

Summary

Confidence

Good - Due to the quality of field observations

Weather Forecast

Light precipitation for this evening, then this weather system should be out of the Sea to Sky region by Sunday morning with another light pulse of weather on Sunday afternoon and into Monday morning. Clear skies and sunny conditions into next week. Daytime freezing levels are expected to be between 1000 and 1500 m for early part of next week, then climbing to 2000 by Wednesday.. Moderate southerly alpine winds are expected tonight, then light winds preominantly from the East..

Avalanche Summary

No recent reports of avalanches in the Sea to Sky region

Snowpack Summary

Up to 50cm of recent storm snow is sitting on a thin breakable crust that caps recent moist snow on rain crust buried last Saturday. Reports suggest this 5 cm thick solid rain crust exists up to at least 2200m. Strong southwest winds may have shifted these new accumulations into touchy wind slabs in exposed terrain. A facet/crust persistent weakness buried mid-March is down approximately 70-130 cm and is still producing hard but sudden results in snowpack tests. This remains the chief concern amongst avalanche professionals in the region due to it's potential for very large avalanches. Cornices are now large and a cornice failure might trigger a large destructive avalanche. Solar aspects will become active with daytime warming.

Problems

Wind Slabs

Reports of soft wind slabs that have developed on lee slopes in the alpine

Use ridges or ribs to avoid pockets of wind loaded snow.>Be alert to conditions that change with elevation.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

No recent reports of activity on this layer. However, it's still there, and should be regarded as potential for large avalanches.

Be aware of thin areas that may propogate to deeper instabilites.>Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches due to the presence of a buried crust/facet layer.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Apr 5th, 2015 2:00PM