Avalanche Forecast

Archived

Feb 18th, 2016–Feb 19th, 2016

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 unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Glacier.

Storm slabs are gaining strength to the underlying surfaces, but can still be triggered by people.

Weather Forecast

A minor front will pass through Rogers Pass today. Steady, light snowfall amounting to 5-10cm is expected with light to mod S ridge-top winds. Freezing levels will gradually drop from 1800m to 1200m tonight. Friday will be mainly cloudy with scattered flurries, mod SW winds, and freezing levels around 1300m.

Snowpack Summary

The past week's storm snow is settling. On solar aspects it sits on a sun crust, while elsewhere it sits on variable surfaces, including isolated surface hoar. The slabs have been reactive in snowpack tests, showing the potential for step-down to lower layers if triggered. The mid- to lower snow pack is well-settled. Cornices grew in the storm.

Avalanche Summary

The avalanche cycle continued to slow yesterday, with several slabs from sz 1.5 to 2.5 observed in the highway corridor. A field team in the Hermit basin observed debris 48+ hours old in the Grizzly Slide path, including some large cornice chunks.

Confidence

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.

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.