Archived

Avalanche Forecast

Feb 14th, 2015–Feb 15th, 2015

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

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

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.

Rain overnight has kept the upper snowpack wet to the tree line where triggering wet avalanches is a concern for riders. There is a chance that the sun can poke out of the clouds sooner than expected. Caution on sun affected slopes if this happens.

Weather Forecast

Lingering rain/snow this morning. Cooling temperatures and clouds dissipating later today as a ridge of high pressure strengthens over the Interior. We will finally begin to see cooler temperatures with a northerly flow of colder air into the middle next week.

Snowpack Summary

11mm of rain overnight and freezing levels to 1900m have further saturated an already moist upper snowpack below tree line. 15cm of new snow in the alpine. The Jan 30 crust layer is down ~1m which formed a crust to 2200m with spotty surface hoar distribution. Jan 15 surface hoar layer is down 100-150cm. The mid and lower snowpack is well settled.

Avalanche Summary

Overnight avalanche cycle attributed to last nights rain event has released several size 3 avalanches within the highway corridor and one size 3.5. These avalanches are very spring like in character, leaving large and heavy deposits. More of such avalanches can be expected in the backcountry.

Confidence

Due to the number of field observations

Avalanche Problems

Loose Wet

The moisture in the upper snowpack at lower elevations will be a concern to riders until lower level temperatures will remain consistently below freezing to form a solid crust.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Storm Slabs

15cm of overnight snow with moderate southerly winds have likely formed some soft slabs on and near ridge crests in the alpine.

Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Likely

Expected Size: 1 - 2

Persistent Slabs

Persistent weak layers within the top 150cm of the snowpack should not be forgotten, especially while temperatures remain warm. Smaller avalanches or cornice failures may step down and propagate on these deep instabilities.

Cornices become weak with daytime heating. Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 3 - 4