Avalanche Forecast
Issued: Feb 16th, 2021 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
Chris Gooliaff,
The faceted upper snowpack is weaker than the normal conditions we enjoy at Rogers Pass. With continuing cold weather, it will not heal as quickly as one would like.
Have patience. Eventually it will warm up and dump once again.
Summary
Weather Forecast
Unsettled grey days with hints of sun and a trace of snow.
Today: Cloudy with sunny periods, Alp high -11*C, light/mod W ridge winds
Wed: Sun and cloud, Alp high -15*C, mod W winds
Thurs: Cloud and sun, Alp high -13*C, mod S winds
Fri: Cloudy, scattered flurries, 5cm, Alp high -10*C, mod S winds
Snowpack Summary
Widespread wind effect in the alpine has made for tricky travel. Large lenses of dense, hard slab are mixed with cold, cream cheese powder. The cold has weakened cornices and the upper snowpack. The January 24th weak interface, down 70-100cm, is faceting and weakening in the cold. The mid-lower snowpack is still relatively strong.
Avalanche Summary
Large natural avalanches to sz 3 were observed from the N side of Macdonald yesterday. Mac 6 ran sz 3, Mac 8, 9, 10, 11 all sz 2-2.5
Old but relevant news: a group of skiers had a close call Wed on the S face of Corbin Peak, triggering a sz 2 and a sz 3 on the Jan 24th persistent weak layer. This problem still lurks on big alpine faces.
Confidence
Problems
Wind Slabs
Variable mod-strong winds have changed the usual wind-loading pattern across various drainages. Look for signs of the recent local wind direction. Features like gullies, bowls, ribs, etc can be cross-loaded where terrain has multiple aspects.
- Watch for reverse loading created by N-NE winds.
- Watch for pockets of hard windslab in steep alpine features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The January 24th weak interface may be triggerable on solar aspects, where facets and/or surface hoar are sitting on a suncrust.
The bond at this interface may be weakening with facets having grown under recent cold temperatures.
- Dig down to find and test weak layers before committing to a line.
- 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 17th, 2021 8:00AM
