Archived

Avalanche Forecast

Apr 4th, 2012–Apr 5th, 2012

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Northwest Inland.

Confidence

Fair - Due to limited field observations

Weather Forecast

A strong ridge of high pressure will maintain sunny skies and light winds for the forecast period. The freezing level should rise to around 1000-1200m each day and return to valley bottom overnight.

Avalanche Summary

No new avalanches have been reported but there are few observers in the field. It's likely that thin wind slabs are the primary issue up high, with solar related activity continuing on sunny slopes during the day.

Snowpack Summary

Moderate winds have blown light amounts of new snow into variable wind slabs in exposed lee and cross-loaded terrain. 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. Below this the snowpack is mostly well settled and strong; however, the mid-February surface hoar (buried 80-120cm deep) may still react to large triggers in isolated terrain. Cornices in the area are reported to be very large and potentially unstable.

Avalanche Problems

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.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

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 - 5