Archived

Avalanche Forecast

Feb 14th, 2018–Feb 15th, 2018

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

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

Regions: Glacier.

Today is a great day to ride/ski fresh, deep snow in the trees.Avoid exposing yourself to avalanche terrain.

Weather Forecast

Walking through the 20cm at Rogers Pass parking lot with your favorite pair of Nike shoes would unenjoyable this morning.Today will bring periods of light snow flurries with sunny breaks, temps ranging from -7 to -11 and 15-30km/hr winds from the southwest. Thursday will be mainly sunny with another pulse of snow arriving early Friday morning.

Snowpack Summary

30cm in the past 24hrs brings our weekly snowfall to 110cm with a height of settled snow of 330cm at 1900m. Moderate southwest winds have redistributed new snow into pockets of wind slab in the alpine and exposed treeline areas. Persistent weak layers are now buried 150-200cm and a sun crust on steep solar aspects is down 20-40cm.

Avalanche Summary

Numerous new avalanches observed this morning while driving the highway corridor to work up to size 3.0.Two days ago a group ascending MacDonald West Shoulder #4 remotely trigger a size 3.0 into NRC Gully from 10m away, the dust cloud settled within a few hundred meters of the highway. Thankfully no one was involved in the avalanche.

Confidence

Avalanche Problems

Storm Slabs

30cm of storm snow has been fallen over night with moderate southwest winds building pockets of wind slab in the alpine and exposed treeline locations. The storm slab will be most reactive along ridge lines, convexities and steep unsupported terrain.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas in the alpine and treeline. Storm snow is forming touchy slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2.5

Persistent Slabs

These slabs will be most susceptible to triggering in shallow areas. This type of instability will linger for a while yet. The significant storms we've seen recently have overloaded these layers, priming slopes to fail only awaiting a trigger.

Avoid thin, rocky or unsupported slopes.Be aware of the potential for large avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2.5 - 3.5

Cornices

Cornices have become reactive in the last week. Strong winds, fluctuating temperatures and significant snowfall has contributed to these loitering hazards failing.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Stay well back from cornices.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 4