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 2nd, 2020–Jan 3rd, 2020

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

Regions

Northwest Inland.

Avalanche danger will increase with heavy snowfall and wind through the day Friday. Under the new snow load, buried surface hoar layers could become reactive, especially to human triggering and would result in large avalanches.

Confidence

Low - Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.

Weather Forecast

Forecast precipitation amounts have seen a significant bump in recent weather model runs for the region.

Thursday night: Flurries accumulating 15-20 cm overnight, moderate southeast wind, alpine temperatures around -12 C.

Friday: Snow accumulating 20-40 cm, bringing storm totals to 30-60 cm. Moderate wind southwest, alpine high temperatures around -3 C by evening. Freezing levels rising to 1000m by evening, then back down to valley bottom overnight.

Saturday: Mix of sun and cloud with scattered flurries accumulating up to 5 cm of snow with another 5-10 cm overnight, moderate southwest wind, alpine high temperatures around -8 C.

Sunday: Mix of sun and cloud with isolated flurries, moderate west wind, alpine high temperatures around -8 C.

Avalanche Summary

A natural windslab avalanche cycle to size 2.5 was reported from the Howson range on Wednesday in response to intense wind transport in the alpine and treeline.

Reports of persistent slab avalanches associated with buried surface hoar have been coming in over the past week, from Ashman, Telkwa and Howson areas. They have been natural and skier triggered, ranging in size from 1.5-3, and have occurred on both north and south aspects mainly at treeline but also in the alpine. The new snow load will increase the size and consequences of avalanches on these layers.

Snowpack Summary

Snowfall overnight and throughout the day will bring new snow totals to 30-60 cm by Friday evening. The accompanying wind will help to create reactive storm slabs in the alpine and treeline. A couple of layers of surface hoar are now buried 50-100 cm below the surface in sheltered areas around treeline. Reports of avalanche activity on these layers suggest they have recently become active, and the new snow load will provide additional stress.

Terrain and Travel

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
  • Be aware of the potential for large avalanches due to the presence of buried surface hoar.

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.