Archived

Avalanche Forecast

Apr 11th, 2014–Apr 12th, 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

3: Considerable

The avalanche danger rating below treeline will be considerable

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

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

Regions: Glacier.

Cloudy skies prevented a good surface crust to develop. Expect unstable conditions from the loose, wet snowpack at lower elevations.

Weather Forecast

We will see brief but intense bursts of convective snowfall, bringing moderate amounts to local areas. Winds will likely gust moderate to strong during these squalls, then back off to light afterwards. Freezing levels will be around 1500-1800m.

Snowpack Summary

A poor freeze has left the surface snow moist and mushy at lower elevations, although some dry snow may be found on due north aspects above 2000m. Extreme winds may have blown this into slabs in exposed lee areas. The mid to lower snowpack is very well settled.

Avalanche Summary

Yesterday, several natural size 2 avalanches were noted from solar and polar aspects. These occurred mainly in the afternoon at the warmest and windiest time of day. A notable size 3.5 occurred at the peak of the warmth 2 days ago on a SW aspect, showing that the persistent weak layers are still active once the snowpack warms up enough.

Confidence

Avalanche Problems

Loose Wet

The cloudy skies overnight prevented a decent crust development. Expect lower elevation snow surfaces to be soft, with temp's getting close to isothermal, creating an unstable snowpack.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Avoid slopes with glide cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Storm Slabs

The 10-15cm of snow from a few days ago was redistributed by strong winds, creating windslabs in exposed alpine and tree-line locations.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

Without a good refreeze, there is less structure to the snowpack to prevent it from stepping down into the lower persistent weaknesses. The large size 3.5 from Moccasin Flats 2 days ago illustrates the potential destructive force lingering out there.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 4