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 18th, 2020–Jan 19th, 2020

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 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.

Regions

South Columbia.

New slabs are expected to grow and become more sensitive as the snow accumulates, the wind continues to blow, and the air temperature increases.

Confidence

High -

Weather Forecast

SATURDAY NIGHT: Cloudy with snowfall, accumulation 2 to 5 cm, moderate to strong southwest wind, alpine temperature -7 C, freezing level below valley bottom.

SUNDAY: Cloudy with snowfall, accumulation 5 to 15 cm, moderate to strong southwest wind, alpine temperature -5 C, freezing level rising to 1000 m.

MONDAY: Mostly cloudy with isolated flurries, accumulation 1 to 3 cm, moderate to strong southwest wind, alpine temperature -3 C, freezing level 1000 m.

TUESDAY: Cloudy with snowfall, accumulation 5 cm, light south wind, alpine temperature -5 C, freezing level 600 m.

Avalanche Summary

Many small to large (size 1 to 1.5) wind slabs were triggered naturally and by humans on Thursday and Friday. They were most often triggered on northwest to northeast aspects but some occurred on south aspects as well. The slab depth ranged from 10 to 100 cm deep and they occurred at treeline and alpine elevations. A few large (size 2 to 2.5) wind slabs were also triggered, suggesting that the wind slabs have the capability of being deep and propagating far.

Persistent slab activity has tapered off in the past week, although there have been occasional reports of large (size 3) explosive-triggered avalanches in alpine terrain (one or two a week).

Snowpack Summary

Strong southwest wind and around 10 to 20 cm of new snow will form fresh storm slabs, with the most reactive slabs being in lee terrain features at higher elevations. The slabs may develop quickly due to relatively warm air temperature.

A thin melt-freeze crust can be found 50-100 cm below the surface in many areas, and beneath that a layer of surface hoar may still be found, which is roughly 80-120 cm deep in the Selkirks and 120-160 cm deep in the Monashees. A facet/crust layer from late November may be found near the bottom of the snowpack. These layers appear to be unreactive at the moment, but could reappear as problems in the future.

Terrain and Travel

  • Watch for fresh storm slabs building throughout the day.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Be aware of the potential for wide propagation.

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.