Archived

Avalanche Forecast

Mar 30th, 2017–Mar 31st, 2017

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

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

3: Considerable

The avalanche danger rating below treeline will be considerable

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

Winter up high and spring down low leaves us with a highly variable snowpack and series of avalanche problems. Make continual assessments throughout the day as conditions can change rapidly.

Weather Forecast

Flurries dissipate today as a ridge of high pressure pushes in for tomorrow, than more unsettled weather on the weekend. Expect cloud, sun and flurries today with trace to a few cm of accumulation. The FL will rise to 1500m today, mod winds from the west and an alpine high of -4. Hoping for cooling temps tonight before the sun comes out tomorrow!

Snowpack Summary

Another 10cm of new snow adds to the incremental loading of late March, depositing 30cm in the last 2 days and over 60cm in the last week @ TL. Multiple crusts exist in the upper snowpack at TL and BTL, warming temps today will turn the surface moist this afternoon at lower elevations. Cornices keep growing in the alpine and should not be trusted!

Avalanche Summary

Artillery controlled avalanches in the Highway corridor up to size 3 yesterday, limited observations of natural avalanche activity due to poor visibility. No reports from skiers/riders in the back country, but there are fewer and fewer people out there as we transition into spring. On the 28th we observed a size 2 glide on a south asp btl.

Confidence

Due to the number and quality of field observations

Avalanche Problems

Storm Slabs

If triggered storm slabs have the potential to step down to deeper layers buried in March or February. Mild temperatures are helping to heal our storm slab problem, as this process occurs the slab properties also increase over any buried weak layer!

Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Loose Wet

No crust recovery overnight and new snow will insulate the upper snowpack at lower elevations. If the sun comes out today, this problem will reach high into tree line and could trigger wet slabs or glide avalanches.

If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 2 - 3

Cornices

Cornices are very large right now and can fail unpredictably - if this happens persistent weak layers deep in the snowpack can be triggered, resulting in very large avalanches.

Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 3