The upper layers of storm snow are sluffing easily in steep terrain. These sluffs can get big enough to push a rider down or even trigger deeper instabilities. Use caution when entering areas that have not avalanched in the last cycle.
Weather Forecast
Cool and dry in the morning, then warming through the day with little precipitation and freeze lines rising to 1400m. No snow at all this weekend but some hope for a storm bringing snow on Monday morning.
Snowpack Summary
Last weeks storm snow has settled out rapidly over the past four days. Below treeline, a rain crust and substantial tree bombs have created treacherous travel in some places. In the alpine, soft slabs overly the Feb 12th PWL, now down over a meter which has been reactive to skiers, especially on solar aspects. Wide propagations are still possible.
Avalanche Summary
No new avalanches were recorded in Glacier National Park for the last two days.
Confidence
Timing or intensity of solar radiation is uncertain
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.