Avalanche Forecast
Issued: Feb 17th, 2020 4:00PM
The alpine rating is Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeBeautiful weather and good snow conditions will make for an excellent day on Tuesday. The sun is higher in late February, so be aware of the increased power of solar radiation on the snowpack. Ice climbers with long exposure times stick to the shade.
Summary
Weather Forecast
NW flow aloft will keep the temperatures relatively cool over the next few days, with overnight lows near -15 and daytime highs reaching -5. With the sun higher this time of year, be wary of the local heat that can develop in sheltered areas from solar radiation. No new snow and light winds are forecast for Tuesday.
Snowpack Summary
Continued settlement and cool temperatures are slowly stabilizing the recently formed windslabs, which could still be triggered in steep, loaded areas in the alpine. Suspect sun crust formation on steep S and SW facing terrain. Weak, facetted snow near the base of the snowpack persists in much of the range, producing isolated but large avalanches.
Avalanche Summary
No new avalanches were observed or reported on Monday, but Sunday saw many windslabs up to size 2 and a couple of very large (size 3.5) avalanches that ran to valley bottom.
Confidence
Problems
Wind Slabs
Recently formed windslabs are stabilizing but can still be triggered by people in steep leeward areas at treeline and in the alpine. Cornices have grown very large in recent weeks, so watch your exposure to them carefully.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Several large avalanches failing naturally on the basal facet/depth hoar have been observed in the past week. These are hard to predict, but are most likely in areas with a thin snowpack (~150cm) where the basal facets and depth hoar are prominent.
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 18th, 2020 4:00PM