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

Dec 9th, 2011–Dec 10th, 2011

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

Regions

South Columbia.

Confidence

Fair - Due to limited field observations

Weather Forecast

Saturday: Expect high clouds with winds reaching 40-70 km/h from the southwest and temperatures climbing to -5. Sunday & Monday: The ridge rebuilds giving mostly clear skies and moderate westerly winds. Freezing levels could peak at 1200m on Monday.

Avalanche Summary

A couple of large (size 2.0-2.5) natural avalanches have been reported releasing along the TCH highway corridor.

Snowpack Summary

The Surface Hoar continues to grow due to the clear and cold nights and the cold temperatures are also promoting near surface facetting. Expect to find a sun-crust that has formed in the alpine on south through west aspects. Wind slabs persist in the alpine and in large openings at treeline. Some areas have a rain-crust below treeline from the 28th of November that has been buried by about 20 cms of snow. This rain-crust may be developing facets, and could become a layer of interest after it is buried by more of a load. There is still some concern associated with the November 7 surface hoar layer. This layer is buried 100-150 cms. Tests are showing that this layer is getting harder to trigger, but if an avalanche does release on this layer, it is likely to be large and destructive.

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.