Avalanche Forecast
Issued: Feb 19th, 2021 8:08AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
Mike Smallwood,
Conditions are complex and changing. New snow buries windslabs and may be a hazard itself where it slabs up or runs loose dry over the drought interface
Summary
Weather Forecast
A westerly 'zonal' flow is setting up over BC bringing flurries today for Rogers Pass followed by a series of fronts Saturday and Sunday. 5cm today with moderate SW winds and a high of -10. 10cm more snow tomorrow with similar moderate SW wind. Heavy snowfall, rising temperatures and strong to extreme W winds on Sunday.
Snowpack Summary
20cm of snow in the last few days covers the cold weakened drought surface. Facets, wind effect and crusts lie under the new snow and make a poor interface for it to bond to. Surface hoar, crusts and facets have still been found down 70-100cm on the January 24th persistent interface. The mid and lower snowpack remain strong.
Avalanche Summary
New snow is building up on a weak interface. Several loose dry avalanches were reported yesterday, running on the drought interface. Recent reports indicates that slabs are still triggerable in isolated areas under the new snow.
Confidence
Problems
Storm Slabs
By the end of today there could be 25cm over the Valentine's Day weak interface of facets and crusts. This will also hide recent windslabs that may still be reactive in unusual areas. Check out this MCR describing the problem in more detail
- Watch for pockets of hard windslab in steep alpine features.
- The recent snow is now hiding windslabs that were easily visible before the snow fell.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The Jan 24th interface has been found in numerous recent profiles. This layer is most concerning on steep, unsupported terrain features on solar aspects
- Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 20th, 2021 8:00AM
