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 19th, 2022–Feb 20th, 2022

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

Regions

Sea To Sky.

Carefully assess the wind effect as you gain elevation. Use extra caution near ridge crests and steep roll overs.

Confidence

Moderate -

Weather Forecast

Saturday night: low of -5 at 1500m. flurries bringing up to 5cm of snow and winds shifting to light northwest.

Sunday: a mix of sun and clouds with no new snow expected. Light northerly winds and a high of -3 at 1500m.

Monday: sunny with a high of -8 at 1500m. Light north winds.

Tuesday: sunny with a high of -12 at 1500m. Moderate north wind.

Avalanche Summary

Early reports Saturday afternoon indicated thin wind slabs were reactive to ski cutting just below ridge crests.. 

On Thursday a natural icefall triggered a size 2.5 avalanche on the slope below. This avalanche was on a northeast aspect at 2100m.

On Wednesday one size one natural cornice fall was observed on a east aspect at 2200m. It was in extreme terrain and did not pull a slab on the slope below.

Snowpack Summary

New snow and southwest winds on Saturday will likely have formed wind slabs on north and east aspects.

The mid February crust is down 10 to 30cm . This melt-freeze crust is reported to exist on all aspects and elevations except for some of the highest elevation polar aspects. Facets have been observed above the crust on polar aspects.

The late-January crust/facet/surface hoar interface is buried down 40 to 100cm. This layer was most reactive between 1700 m and 2000 m. While this layer now appears to be dormant in many parts of the region it may be possible to trigger it with a large load or in shallow snow pack areas at upper treeline or lower alpine features on polar aspects.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Closely monitor how the new snow is bonding to the crust.
  • Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.

Problems

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.

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.