Stay aware of changing conditions. Danger may be locally higher due to more intense precipitation or wind.
Confidence
Fair - Due to variable snopack conditions
Weather Forecast
Saturday: Mostly cloudy with flurries. Expect moderate southwest winds and temperatures reaching -4. Due to the nature of the weather pattern, expect more precipitation on the western half of the region and on west facing slopes. Sunday: A weak cold front passes through the region giving unsettled skies with a chance of flurries. Continued southwest winds and freezing levels reaching 1100m. Monday: Expect clearing conditions under southwest winds and freezing levels to 1100m.
Avalanche Summary
Recent explosive control yielded one 2.0 slab, and we have a report of a small accidental skier triggered slide with no involvement. Both of these events were in the northern part of the region. As the load increases through the weekend, the likelihood of triggering will go up. Threshold for human triggering will precede natural releases.
Snowpack Summary
Northern and western areas have seen up to 50 cm of recent storm snow, while areas further south have seen only 20cm. Consistent westerly winds have lee loaded alpine and open treeline terrain, creating a windslab problem. In many areas, the new snow sits above a well developed surface hoar layer from mid December. Stability test still show sudden results on this layer in the moderate to hard range, and whole block rutchblocks have also been reported. Where this layer is present, it should be treated with respect. Lower in the snowpack, the mid-layers are well-consolidated and strong.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.