Avalanche Forecast
Issued: Feb 22nd, 2021 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
Chris Gooliaff,
Our winter wonderland was walloped by a warm, wet, and windy wild one.
A natural avalanche cycle is occurring in the Rogers Pass area, with numerous large avalanches from size 3 to 4.
I highly recommend you visit your local ski hill today.
Summary
Weather Forecast
Passage of the main storm front this morning, then unsettled afterwards.
Today: Cloudy with locally intense flurries, 5-10cm, FZL 1500m, Alp high -5*C, mod/gusting extreme S winds
Tues: Cloudy with flurries, trace amounts, FZL 600m, Alp high -12*C, mod W winds
Wed: Cloudy with sun and flurries, Alp high -12*C, mod SW winds
Snowpack Summary
Extreme south winds and a warm 40mm of precip overnight. The Feb 14 drought interface is now down 50-70cm in sheltered areas; this interface is predominantly a wind crust in exposed areas near the height of the pass, and buried windslabs and facets as you move East and West. Facets and a weak suncrust still linger down 80-100cm on the Jan 24th PWL.
Avalanche Summary
We are in the tail-end of a natural avalanche cycle, with large (up to sz 4), naturally-occurring avalanches running in many paths. Observations from the overnight shoot include numerous sz 3-4 artillery-controlled avalanches both east and west of the Pass. Natural activity should drop with the passage of the front and cooling later this morning.
Confidence
Problems
Storm Slabs
60+cm of storm snow is being redistributed by strong/extreme S'ly winds. This lies over the Valentine's Day weak interface of facets, crusts and variable wind effect. Slab properties have developed and are failing on this layer.
- Avoid exposure to avalanche terrain, large avalanches may reach the end of run out zones.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The Jan 24th interface has been found in numerous recent profiles. This layer has awakened with increased load from the storm. It is most concerning on steep, unsupported terrain features on solar aspects, where it exists as a sun crust.
- Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust
- If triggered the persistent slab may step down to deeper layers resulting in large avalanches.
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 23rd, 2021 8:00AM
