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 16th, 2023–Dec 17th, 2023

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

Regions

Glacier.

Triggering the Dec 1st surface hoar is still possible in areas that have not previously avalanched. With new snow hiding old avalanche debris, this is getting more difficult to assess. The safest way to manage this problem is by sticking to conservative terrain.

Confidence

Moderate

Avalanche Summary

On Saturday, we saw a few large storm slab avalanches in the steep terrain of the Eastern Highway Corridor.

On Thursday, just to our East an experienced group triggered a size 2 avalanche on the Dec 1 surface hoar and 1 skier was partially buried.

Earlier in the week, two separate groups reported near misses, triggering large avalanches on the Dec 1st surface hoar layer. One was on Ursus Minor, and the other was near the base of the 7 steps, in the Asulkan valley.

Snowpack Summary

Up to 20cm of recent snow buries wind effect, spotty surface hoar, and a thin sun crust in steep terrain.

A rain crust down 40-50cm is present up to 2100m.

A weak layer (Dec 1st surface hoar) is buried 50-90cm deep, continues to produce 'sudden' results in snowpack tests and has been the failure plane for several human triggered avalanches recently.

The base of our unseasonably thin snowpack is unsupportive and facetted in shallow areas at upper elevations.

Weather Summary

A ridge of high pressure moves into the interior. Expect stable weather, with warming temps and valley cloud, for the next couple of days.

Tonight: Clear periods, Alpine low -7°C, Moderate SW ridgetop winds.

Sun: Mainly cloudy, High -3°, Freezing level (Fzl) 1400m, Light SW Wind.

Mon: Sunny periods, Low -2 °C, High 0 °C, Fzl 2000m. Light S wind.

Tues: Flurries (5cm), Low -5 °C, High -2 °C, Light SW wind. Fzl 1600m.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Be mindful that deep instabilities are still present and have produced recent large avalanches.

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.