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 11th, 2013–Jan 12th, 2013

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

Sea To Sky.

Confidence

Good

Weather Forecast

Saturday: A mix of sun and cloud with a chance of flurries close to the coast. Freezing level is at valley bottom with alpine temperatures around -10. Winds are light from the north-northwest. Sunday: A mix of sun and cloud. Freezing level remains at valley bottom. Winds are light to moderate from the north. Monday: A mix of sun and cloud. Alpine temperatures should rise during the day with an above freezing layer developing. Winds are moderate from the north. 

Avalanche Summary

There are a few reports of accidentally triggered slab avalanches up to size 2 on Thursday. A widespread natural avalanche cycle was observed on Wednesday with numerous slab avalanches up to size 2 and a few larger events up to size 3.

Snowpack Summary

A dusting of up to 15 cm of new  snow sits on the 40-60 cm of snow that fell earlier this week. Northerly outflow winds have created thin new wind slabs in exposed terrain, while older wind slabs still exist from the previous storm. Below the storm snow is a weak layer of surface hoar, facetted snow, and/or a crust. Snowpack tests on Wednesday continued to yield easy to moderate sudden planar, or "pops", results on this interface. No significant weaknesses have been reported recently below this in the mid snowpack layers. Near the base of the snowpack, a crust/facet layer exists, which is now unlikely to be triggered, except perhaps by heavy triggers in steep, shallow, rocky terrain where more facetting has taken place.

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.