Avalanche Forecast
Issued: Feb 17th, 2021 8:18AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
ross campbell,
Summary
Weather Forecast
Some isolated light flurries are possible over Rogers Pass from the passing upper trough this morning. Alpine temperature will hover in the -10 range, and winds will be light, possibly gusting moderate from the West. A clearing trend tonight, with light winds from the SW. Tomorrow a mixed bag of weather, with snow on the way this weekend.
Snowpack Summary
10-20cm of new snow covers a variety of old surfaces, from hard wind slabs in the alpine and exposed areas of TL, to low density facetted snow in sheltered areas at TL and below. The cold has weakened cornices and the upper snowpack. The January 24th interface is down 70-100cm and unreactive in stability tests.
Avalanche Summary
No new avalanches were observed int he HWY corridor yesterday. 2 size 1 slab avalanches were noted by field teams yesterday up Connaught Creek. 1 from Cheops North 1, and the 2nd on a west aspect above Ursus Trees.
Confidence
Problems
Wind Slabs
The wind slabs are widespread; however, they are only reactive in isolated terrain features. Cold temperatures have facetted the snow under the wind slabs. There is an excellent MCR describing this problem in more detail that can be found here.
- Watch for pockets of hard windslab in steep alpine features.
- Watch for reverse loading created by N-NE winds.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The Jan 24th interface has been easily found in numerous recent profiles; however, no results have been recorded as this layer becomes harder to trigger. There is still a lingering possibility that it could be triggered on steep solar aspects.
- Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust
- Dig down to find and test weak layers before committing to a line.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 18th, 2021 8:00AM
