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 8th, 2013–Feb 9th, 2013

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 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.

Regions

South Columbia.

Blue skies, sunshine and fresh snow may tempt you into steeper and bigger terrain. Maintain a diligent approach to terrain selection to best manage the current conditions. If the sun comes out watch solar slopes, they may deteriorate.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

A strong ridge of high pressure builds off the coast allowing a cool, dry NorthWest flow over the region with high diurnal temperature variations. Scattered too few clouds will exist allowing some sunny alpine skies on Saturday with more predominant sunny skies on Sunday. Ridgetop winds will blow steady and  light-moderate from the NorthWest. Treeline temperatures will hover near -3 and freezing levels will rise to 1000 m during the afternoon periods.

Avalanche Summary

Natural avalanche activity loose and slab avalanche activity up to size 2 occurred on Thursday. The natural cycle has slowed down significantly, yet the rider triggered avalanches are ongoing. We have continued to receive reports of rider triggered slab avalanches up to size 2 throughout the region. Most of these cases still involving the persistent weak layers below the surface. They snowpack remains touchy to light loads. Avalanche activity may continue through the forecast period, additional concerns being solar radiation as a natural trigger.

Snowpack Summary

New snow (20-40 cm) adds to the recent storm slab which sits on a surface hoar layer and a sun crust layer that developed at the beginning of February. This layer continues to be reactive. Deeper down (between 40-80 cm) sits an old sun crust and well preserved surface hoar that was buried on January 23rd. This persistent slab has been reactive and easily triggered over the past few days, especially from solar aspects and at treeline and below treeline over steeper convex slopes.Wind slabs persist in the alpine and at treeline. The loading pattern may change due to winds switching from the SouthWest to the NorthWest and form pockets of wind slab in unsuspecting places. At lower elevations a melt-freeze crust has formed due to the recent high freezing levels.The mid-pack is well settled and strong. Watch the duration and intensity of the sun in your local riding area; it may weaken the upper snowpack. Cornices loom and threaten slopes below.

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.