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 5th, 2019–Dec 6th, 2019

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

Regions

Northwest Coastal.

Caution as you transition into wind-exposed terrain. Avalanches are possible where winds have transported the recent snow into slabs on lee terrain features at upper elevations.

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Thursday night: Clearing skies, no precipitation, light variable winds, alpine temperature -10 C

Friday: Cloudy with periods of sun, no precipitation, light variable winds, alpine high temperature -7 C

Saturday: Mostly clear, no precipitation, light northerly winds, alpine high temperature -7 C

Sunday: Mix of sun and clear, no precipitation, moderate northwest winds, alpine high temperature -5 C

Avalanche Summary

Recent wind slab avalanches up to size 2 were reported in the Bear River Pass area on lee terrain features in the alpine. As snowfall and wind tapers, these wind slabs may remain reactive to human-triggering.

Snowpack Summary

Southwest winds have been transporting the recent snow into wind slabs on lee features at upper elevations. Since Sunday, snow totals in the 20-35 cm range have accumulated across the region, with higher amounts falling further north in areas such as Bear River Pass. With incremental accumulation and ongoing southwest winds, wind slabs are the primary concern. Depending on location, these slabs are likely sitting on a mix of sugary faceted snow, and feathery surface hoar crystals, and hard wind-affected snow that may be reactive to human triggering.

Total snowpack amounts are likely in the 60-140 cm range, tapering quickly at lower elevations.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.