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.
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.
Continued reports of whumphing 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.
A series of small systems will deliver 5-10cm a day until Friday. Winds will remain in the moderate range, gusting to strong from the SW. Temps will rise slightly on Wednesday with an Alpine high of -4 and a freezing level to 1600m.
New snow and moderate SW winds are creating new wind slabs in lee areas at and above treeline. In most 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.
No new natural avalanches observed or reported. Explosive control at local ski areas produced sz 1 wind slabs in immediate lees on Tuesday. Reports of whumpfing, as well as explosive and skier triggered avalanches up to size 2 on the deep persistent layer have occurred in the past week, we expect this layer to continue to be problem for a while.
