Avalanche Forecast

Issued: Apr 5th, 2012 10:10AM

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

ccampbell, Avalanche Canada

Northwest Inland.

Summary

Confidence

Good

Weather Forecast

A ridge of high pressure is expected to keep the northwest ranges mainly sunny and dry with light winds throughout the forecast period. Freezing levels are expected to reach 1500m during the day, but drop back down to valley bottoms at night.

Avalanche Summary

Reports from Wednesday include some larger wet sluffs from steep rocky sun-exposed terrain. Cornices have also been failing over the past couple of days, some of which triggered wind slab avalanches up to Size 2 on the slope below.

Snowpack Summary

Moderate winds have blown light amounts of new snow into variable wind slabs in exposed lee and cross-loaded terrain, which are starting to bond. Surface snow on sun-exposed slopes is undergoing a daily melt-freeze cycle. In sheltered areas 15-30cm of new snow sits on the previous surface that includes crusts (found on all aspects below 1000m and on solar aspects higher up), and old wind slabs. Not only will daytime warming and sun-exposure cause surface snow to lose cohesion and cornices to weaken, they will also increase settlement rates and decrease slab stability.

Problems

Loose Wet

Loose wet avalanches are likely on sun exposed slopes during the day. Isolated wet slab avalanches are also possible.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Large cornices exist in alpine terrain and they may pop off with warmer temperatures and intense solar radiation. A failure could be destructive by itself, and could also trigger an avalanche on the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Wind Slabs

Thin wind slabs have formed in exposed lee and cross-loaded features. Watch for triggering in gullies, behind ridge crests and over rolls in terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 6th, 2012 9:00AM