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 22nd, 2021–Feb 23rd, 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 unlikely, human triggered possible.
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.

Regions

Northwest Inland.

Avalanche danger remains elevated as the storm quiets and all the recent snow stabilizes. Conservative terrain travel is warranted.

Confidence

High -

Weather Forecast

MONDAY NIGHT: Cloudy with snowfall, accumulation 5 to 10 cm, 40 to 60 km/h west wind, alpine temperature -10 C.

TUESDAY: Cloudy with snowfall and afternoon clearing, accumulation 5 to 10 cm, 30 to 40 km/h northwest wind, alpine temperature -11 C.

WEDNESDAY: Increasing clouds with afternoon snowfall, accumulation 2 to 5 cm, 30 to 40 km/h southwest wind, alpine temperature -10 C.

THURSDAY: Cloudy with snowfall, accumulation 10 to 20 cm, 60 km/h southwest wind, alpine temperature -8 C.

Avalanche Summary

Widespread avalanche activity is expected to have occurred over the weekend, for example as described in this MIN. Looking ahead, similar storm and wind slab avalanche activity may continue into Tuesday as more snow and strong wind are forecast.

Snowpack Summary

40 to 60 cm of snow and strong southwest wind has formed new storm and wind slabs. Another 10 to 20 cm of snow and strong west wind are forecast for Monday night and Tuesday, building on these slabs. All this snow overlies hard wind-affected snow in exposed terrain and weak, faceted snow or surface hoar crystals in sheltered terrain, suggesting it may take some time for the new snow to bond to these surfaces.

There hasn't been avalanche activity on deeper weak layers for some time. Once we see a substantial warm-up, we'll be thinking about the potential for deeply buried weak layers to reactivate.

Terrain and Travel

  • Choose conservative terrain and watch for clues of instability.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

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.