Avalanche Forecast
Issued: Feb 20th, 2018 4:31PM
The alpine rating is Wind Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
High - The weather pattern is stable
Weather Forecast
A fairly benign weather pattern is expected through the forecast period. Wednesday: Cloudy with isolated flurries. Alpine temperatures near -12 and ridgetop winds light to moderate from the West.Thursday: Mostly sunny with some cloud cover. Alpine temperatures near -10 and ridgetop winds light to moderate from the North.Friday: Mainly cloudy with some new snow. Alpine temperatures near -9 and ridgetop winds strong from the southwest.
Avalanche Summary
On Monday, numerous wind slabs and cornice failures were reported. Most wind slabs were reactive to rider triggers, and explosive control up to size 2 on all aspects above 1800 m. The cornice failures were triggered by explosives but not pulling a slab or entraining much mass from the slopes below. With little change in the weather forecast natural avalanche activity will subside, but human triggers remain possible.
Snowpack Summary
In exposed terrain, strong north winds have scoured north facing slopes and loaded south facing slopes. In sheltered terrain, especially in the trees the cold weather is preserving 30-40 cm of low density snow. A crust layer can be found beneath the storm snow on sun-exposed slopes and below 1900 m, which has supported some wide propagations in recent storm slab avalanches. Deeper in the snowpack, avalanche professionals are still monitoring the mid-January crust. This layer is now 150-200 cm deep, but a heavy trigger (cornice?) or the next major storm (warming and loading) could potentially wake up this layer.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 21st, 2018 2:00PM