Avalanche Forecast
Issued: Feb 18th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
William Lawson,
Parks Canada
Beautiful weather and good snow conditions will make for an excellent day Wednesday. 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
A 10 to 15 degree fluctuation from evening lows to daytime highs is forecasted for the week. In the alpine this temperature swing is not as prevalent, an inversion will form over night and temps will stay steady at -6. Clear skies Wednesday and Thursday will bring increased solar inputs on Southerly aspects. Winds will remain light for Wednesday.
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 Tuesday. Over the weekend we received a few reports of very large (size 3.5) avalanches failing on the deep persistent week layer 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 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.
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 19th, 2020 4:00PM
