Avalanche Forecast
Issued: Feb 7th, 2018 4:37PM
The alpine rating is Storm Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
Thursday: 15-30 cm overnight Wednesday at upper elevations, with the higher accumulations being in the southern part of the region. 5-15 cm Thursday morning tapering off by early afternoon. Ridgetop winds strong from the southwest. Alpine temperatures near -5 with freezing levels 1300 m. Friday: Mix of sun and cloud with alpine temperatures near -8 and freezing levels at valley bottom. Ridgetop winds light from the north. Saturday: Mostly clear with no forecast snow. Alpine temperatures near -10 and ridgetop winds light from the northeast.
Avalanche Summary
On Tuesday, no new avalanche observations were reported from the northern part of the region (Duffy). In the south (Cascades) numerous glide avalanches up to size 3 were reported. Glide releases have a higher likelihood of failing when the ground cover is smooth bedrock or grass. Other avalanches to note from the south include wet slab avalanches up to size 2.5 with one reported as a size 3 from a steep southeast slope near 1700 m. Natural avalanches are likely with forecast storm snow, rain at lower elevations and strong ridgetop winds.
Snowpack Summary
Recent snowfall totals are highly variable. In the south, up to 20 cm of new snow fell bringing the alpine totals up to 40 cm since the weekend. In the north, new snow totals are half that and rapidly decreasing below 1800m. This new snow sits on old wind slabs in alpine locations and has buried a crust at treeline. At lower treeline and below elevations, warm temperatures (and rain in many locations) have created heavy snow conditions. This new snow adds to the 80-150 cm mid pack that sits above the mid- January crust, which generally shows signs of bonding. I would still remain suspect of this deeper layer, especially now, with additional load stressing the snowpack. Large fragile cornices could also act as a trigger on the slope below.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 8th, 2018 2:00PM