Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Feb 21st, 2014–Feb 22nd, 2014

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

Little Yoho.

We are strongly urging people to be very conservative this weekend with their terrain choices. This is due to the nature of the weak layer currently in the snowpack. SH

Weather Forecast

Expect flurries with local amounts of 5cm on Saturday. Temperatures will be in the -15 to -20 range over the weekend. Light gusting moderate NW winds for Saturday.

Snowpack Summary

30-70cm of recent storm snow is settling and overrides the Feb10th interface. A poor bond persists at this interface and many avalanches have been observed on this layer over the past week. Recent SW winds have created wind slabs in lee alpine terrain. These wind slabs are easily triggered and often step down to the Feb 10th interface.

Avalanche Summary

The natural avalanche cycle seems to have subsided, but skier triggered avalanches (up to class 2) were reported in the Lake Louise on Thursday, and two skier remotes were reported on the moraine approach to Peyto Glacier on Wednesday. Avalanche control on Mt. Whymper today produced avalanches to sz 2.5, likely failing on the Feb.10th interface.

Confidence

Due to the number of field observations on Friday

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.