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 27th, 2012–Jan 28th, 2012

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

Regions

South Columbia.

Confidence

Fair - Freezing levels are uncertain on Monday

Weather Forecast

A significant storm system enters the region Saturday evening bringing 30 - 40 cm of new snow. This system exits the region Sunday as freezing levels climb to 1300 m. Average seasonal temperatures return Monday while a weak ridge of high pressure builds into the forecast area.

Avalanche Summary

Several skier triggered size 1 avalanches were reported yesterday as new snow was blown into soft slabs by strong NW winds. A natural cycle driven by the winds was reported from a few different locations. Avalanches from size 1 - 3 were reported.

Snowpack Summary

60 - 100 cm of storm snow has fallen in the last week across the province. While storm shears have been quick to heal, winds have had a dramatic effect on wind exposed terrain at all elevation bands. Soft slabs of 10 - 30 cm were reported Thursday as winds switched to the NW and blew at moderate to strong values.All the new snow is sitting on cold dry snow formed during last week's Arctic Outbreak. The cold dry air created a layer of facets that are being referred to as the Jan 20th, facets. A Rutschblock test in the north showed a result of RB6, MB down 90 on this layer. In the south a CTE test produced a failure down 70 at this interface.The January 13th SH/FC layer is spotty in distribution, but it is still capable of performing. Deep in the pack the mid December layer is gaining strength, but may still be an issue in areas of thin shallow snowpack.

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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

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.