Avalanche Forecast
Regions: Little Yoho.
The avalanche hazard is increasing with the arrival of new snow and wind. We also have a lot of uncertainty about where the deep persistent layer might be triggered. As a result it is a good time to be patient and make conservative terrain choices.
Weather Forecast
A series of systems will reach the forecast region with light snowfall over each of the next few days. Amounts of about 5 cm each day are expected, though some forecasts are much higher. Winds will remain strong in the alpine for Tuesday and start to taper off on Wednesday. Treeline temperatures remain mild and steady between -10 and -5 'C.
Snowpack Summary
New snow and moderate to strong SW winds are creating new wind slabs in lee areas at and above treeline. In many areas the upper snowpack of denser snow sits over a weak mid and lower snowpack consisting of facets, depth hoar and crusts. In deeper snowpack areas these weaknesses are less pronounced. Snowpack depths at treeline average 100-160+ cm.
Avalanche Summary
No new avalanches observed or reported on Monday. Reports of whumpfing, as well as explosive and skier triggered avalanches up to size 2 on the deep persistent layer of facets and depth hoar have occurred in the last several days, and we expect this layer to continue to be problem for a while. A few smaller wind slabs were also reported recently.
Confidence
Forecast snowfall amounts are uncertain
Avalanche Problems
Wind Slabs
Moderate to strong winds and new snow over the next couple days will build wind slabs in lee areas at treeline and above. These will be easy to trigger so avoid lee loaded areas and minimize your time in areas with wind loading going on above you.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Deep Persistent Slabs
Continued reports of whumphfing on the weak, faceted lower snowpack indicate the potential for human triggering. This likelihood will rise with new snow and wind over the next few days. Triggering the deep facets could result in a large avalanche.
- Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.
- Use careful route-finding and stick to moderate slope angles with low consequences
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2 - 3