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 18th, 2021–Dec 19th, 2021

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 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.

Regions

Glacier.

Expect the new storm slab and dry loose avalanches to be reactive on Sunday as the storm tapers off.

The Dec 1 persistent weak layer is a growing concern. Assess the snowpack before committing to larger avalanche terrain.

Weather Forecast

Snow will continue to fall until early Sunday morning, with another 10cm of accumulation overnight, totalling ~30cm in the storm. As the storm leaves the region, the winds and temps will drop with an alpine high of -15 as an arctic high pressure system settles in for a few days. Clearing skies and cooler temps for Monday and Tuesday.

Snowpack Summary

Excellent snow quality can be found throughout the Park wit 20cm of new snow over the past 24 hours, totalling ~30cm in the last few days. The Dec 1 crust is ~10cm thick, buried a ranging depth of 50-100cm, and can be found up to 2300m. Facets observed above and below this crust, particularly in shallow snowpack areas at and just below tree line.

Avalanche Summary

Limited visibility due to the raging winter storm, but suspect a natural avalanche cycle up to sz 3.0 to occur by early Sunday morning.

Snowpack tests continue to give sporadic sudden results on the Dec 1 crust, particularly in shallower snowpack areas at tree line.

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.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.