Archived

Avalanche Forecast

Feb 26th, 2014–Feb 27th, 2014

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Northwest Inland.

Check out the new Forecaster Blog for an update on the “Touchy Weak Layer.”

Confidence

Good

Weather Forecast

Overnight and Thursday: Cold and clear overnight with moderate Northerly winds. Clear and sunny with freezing levels at valley bottoms and light Northerly winds. No precipitation.Friday: Clear, sunny, and cold with moderate Northerly winds.Saturday: Continued clear, sunny, and cold with moderate Northeast winds.

Avalanche Summary

One size 2.5 natural wind slab avalanche was reported from a West aspect at about 1500 metres during a period of strong Easterly winds.

Snowpack Summary

Clear skies and cold temperatures combined with moderate Easterly or Northeasterly winds have developed new wind slabs in the alpine and at treeline. 35-90 cm of settled storm snow overlies a variety of old surfaces including weak facets, surface hoar (more predominant at tree line and below tree line elevations), a scoured crust, wind pressed snow, or any combination of these. Whumpfing, cracking, and reports from the field indicate a very poor bond between the new snow and these old surfaces. Recent snowpack tests give easy or moderate "pops or drops" shears on this persistent weakness and show potential for wide propagation. A lack of activity on this layer is likely because the overlying snow has not settled into a slab due to the recent cold temperatures.

Avalanche Problems

Persistent Slabs

The early February persistent weak layer of buried facets and crusts continues to be a concern for human triggering. Cold temperatures are not expected to help settle and bond this weak layer.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Use conservative route selection, stick to moderate angled terrain with low consequence.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Wind Slabs

North thru East winds have developed new wind slabs on lee aspects. These wind slabs may be rider triggered and may step down to the Early February persistent weak layer.

Use ridges or ribs to avoid pockets of wind loaded snow.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 4