Avalanche Forecast
Issued: Jan 22nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
Tim Haggarty,
Strong temperature inversions spell cold mornings on the skin track or on valley bottom climbs. Use the sun to your advantage if possible and carry extra layers to be prepared for un-expected delays or emergencies.
Summary
Weather Forecast
Temperatures were at -28C in valley bottom while it was and -10 to -18 at treeline to start the day. A cold front will push south through Alberta Friday night. Although it seems unlikely this will reach as far west as the divide, it does threaten cloud for Saturday morning (perhaps more over the east) and potentially an increase in alpine winds.
Snowpack Summary
Significant wind effect exists in all alpine areas with isolated wind slabs in steep loaded areas of the high alpine. Soft surface snow remains just below ridge crests at treeline. The upper snowpack is faceting. This has diminished the sensitivity of wind slabs, and rendered the four layers of surface hoar visible in the upper meter, as dormant..
Avalanche Summary
A large avalanche occurred Wednesday night - a size 3.5 from the big face on Mt. Lefroy. A similar event was reported on West edge of Kootenay National Park today. Both likely a result of extreme winds on Tuesday. Further evidence of this event can be seen in the form of cornice failures and numerous small wind slabs in alpine lee features.
Confidence
Due to the quality of field observations
Problems
Wind Slabs
Extreme winds on Tuesday night blasted most alpine terrain. Expect some lingering, isolated slabs in leeward alpine areas and widespread wind effect into treeline. Use care with these slabs especially in steep or committing terrain features.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Tough ski conditions increase the risk of injury which would be serious in the cold temperatures.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 23rd, 2021 4:00PM
