Archived

Avalanche Forecast

Nov 29th, 2014–Nov 30th, 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

3: Considerable

The avalanche danger rating at treeline will be considerable

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

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Glacier.

The storm may have passed but instabilities will linger with 2 buried weak layers present. Large avalanches are still possible as the sun pokes out for the first time. Watch your exposure to overhead hazard.

Weather Forecast

A high pressure ridge has set up over the interior keeping things cold and dry as Arctic air pushes south. Lingering flurries today with clearing and north westerly winds. This is expected to last into next week.

Snowpack Summary

120cm of storm snow has fallen over The Nov 21 surface hoar/sun crust layer now down ~ 90 and Nov 9 rain crust down ~110cm. Large whoomphing and cracking were observed yesterday and prior to the storm between specially 1600 and 2000m. Cold temperatures have likely tightened up the snowpack where it had been rained on.

Avalanche Summary

A fresh size 3.0 came down this morning along the highway. Natural avalanche cycle yesterday morning produced avalanches that began dry but ended moist up to size 3.5 along the highway in all major paths. Avalanche control yesterday produced large avalanches to size 3.5. Natural activity tapered off as the temperatures cooled down later in the day.

Confidence

Due to the number of field observations

Avalanche Problems

Persistent Slabs

2 persistent weak layers are buried down ~1m. Lots of whoomphing and cracking have been observed on these layers in the last few days. Expect this to be most reactive between 1600 and 2000m This problem will linger for some time.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Storm Slabs

60cm of storm snow in the past two days will mean lingering instabilities before things have a chance to settle. Winds associated with it were very strong yesterday morning so expect to encounter some wind slabs up high.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3