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

Jan 3rd, 2021–Jan 4th, 2021

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

North Columbia.

  

Recently formed storm slabs will be most reactive in wind affected areas at treeline and above. Be especially cautious as you transition into wind affected terrain.

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

  

SUNDAY NIGHT: Cloudy with flurries; 3-5 cm. / Moderate, south ridgetop wind / alpine low temperature -11 / Freezing level valley bottom.

MONDAY: Snow; 5-10 cm, with another 5-10 cm overnight. / Strong, south ridgetop wind / alpine high temperature -6 / Freezing level valley bottom.

TUESDAY: Cloudy with isolated flurries; 0-3 cm. / Strong, southwest ridgetop wind / alpine high temperature -5 / Freezing level 900 m.

WEDNESDAY: Snow; 5-10 cm. / Strong, southwest ridgetop wind / alpine high temperature -4 / Freezing level 1300 m.

Avalanche Summary

On Sunday, numerous explosive triggered storm slab avalanches up to size 3.5 were reported just west of revelstoke.

On Saturday, a skier triggered a size 2 slab avalanche near the Gorge area. See the excellent MIN report Here.

Recently formed storm slab will be most reactive in wind affected terrain at treeline and above.

Snowpack Summary

15-25 cm of new snow brings recent snow totals to around 50 cm. Strong southwesterly winds, and mild temps have formed widespread storm slabs at all elevations.

Two persistent weak layers buried in early/mid Dec. are now 110-160 cm below the surface. The form and distribution of these layers are HIGHLY VARIABLE and have created conditions that can vary significantly from one valley to the next. The first layer has been primarily reported as small surface hoar. The next layer has been reported as a thin freezing rain crust, surface hoar, or thick rain crust depending on elevation and location. As a result, diligent investigation of the snowpack is required to get a handle on local conditions.

Terrain and Travel

  • Avoid lee and cross-loaded slopes at and above treeline.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Be aware of the potential for large avalanches due to the presence of a persistent slab.
  • Uncertainty is best managed through conservative terrain choices at this time.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.