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Avalanche Forecast

Dec 5th, 2019–Dec 6th, 2019
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

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.

Avalanche Problems

Wind Slabs

Southwest winds have likely been transporting the 20-35 cm of recent snow into wind slabs at upper elevations. These slabs are unlikely to bond well with the previous snow surfaces.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2