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

Feb 7th, 2020–Feb 8th, 2020

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

Regions

South Rockies.

A thick crust in place means that avalanche problems are mainly confined to the upper snowpack. This forecast is based on 5 to 10 cm Friday Night, but if we wake up with more than 15 cm Saturday morning bump each danger rating up one level and keep the terrain choices in check.

Confidence

Low - Forecast snowfall amounts are uncertain.

Weather Forecast

A bit of storm snow Friday Night into Saturday, and then clear skies through the rest of the forecast period.

FRIDAY NIGHT: Freezing level at valley bottom, moderate to strong southwest wind, 5 to 10 cm of snow.

SATURDAY: Overcast, freezing level near valley bottom, light to moderate northeast wind, 5 to 8 cm of snow.

SUNDAY: Clear skies, freezing level rising to 1000 m, light to moderate wind generally out of the west, no significant precipitation expected.

MONDAY: Clear skies, freezing level rising to 1000 m in the afternoon, light northwest wind, no significant precipitation expected.

Avalanche Summary

Loose dry avalanches to size 1 were observed Thursday from extreme terrain, but aside from that, no significant avalanche activity has been reported since last weekend. A natural avalanche cycle during last weekend's storm included some large (size 2.5) deep persistent slab avalanches in the Elk Valley (see photos in this MIN report) that appear similar to avalanches in that area in mid-January, which suggests the deep persistent slab problem will continue to resurface during stormy periods.

Snowpack Summary

Variable amounts of wind affected snow sits above a widespread rain crust that exists up to roughly 2100 m. The Elk Valley has 5-15 cm of snow above the crust and the eastern slopes have 15-30 cm above the crust. There have been observations of surface hoar forming in the Elk Valley previous to Friday Night's storm, check that out here. A well consolidated mid-pack overlies generally weak basal facets, that may be possible to trigger in isolated shallow rocky start zones.

Terrain and Travel

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Watch for fresh storm slabs building throughout the day.
  • Recent new snow may be hiding windslabs that were easily visible before the snow fell.

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.