Avalanche Forecast
Issued: Jan 18th, 2020 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
percy woods,
Parks Canada
Watch for windslab in exposed areas. These slabs may be sensitive to human triggering.
Summary
Weather Forecast
Scattered flurries with 4cm accumulation forecast for today accompanied by Southerly winds in the 20km/h range and a 700m freezing level. Cloudy with sunny periods and a rising freezing level to 1500m on Sunday accompanied by moderate Southerly winds. Monday looks very similar to Sunday with a shift to moderate winds out of the SW.
Snowpack Summary
Strong southerly winds have redistributed 15cm of new storm snow. Reactive wind slabs have formed in exposed areas above treeline. The Dec 27th surface hoar/ crust layer is buried approximately 100cm. The mid and lower snowpack are generally well settled and strong.
Avalanche Summary
Eight avalanches including one size 3 over the last two days in the highway corridor east of Rogers Pass. No new backcountry avalanches reported or observed.
Confidence
Problems
Wind Slabs
Multiple field teams confirmed the presence of easily-triggered soft wind slabs in exposed areas at all elevations. Expect this problem to persists today. These slabs can have larger than expected propagation.
- Watch for whumpfing, hollow sounds, and shooting cracks.
- Use caution in lee areas. Recent wind loading have created wind slabs.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The December 27th surface hoar layer persists down approximately 100cm. This layer is becoming less reactive in stability tests and it is increasingly harder to find in snow profiles, but the potential is still there to get surprised.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 19th, 2020 8:00AM
