Direct sun & warmth are currently the primary drivers of hazard and the weather forecast indicates that Thursday will be quite warm. Minimize your exposure to large slopes if the snowpack becomes moist or wet.
Weather Forecast
THURSDAY: Freezing level starting at 1500m, rising to 2100m. Initially calm, winds increasing in the afternoon to Light S/SW winds at treeline, Moderate S/SW winds at ridgetop. No significant precipitation. Clear skies.FRIDAY: Freezing level holding at 1800m. Strong south winds at treeline, strong to extreme SW winds at ridgetop. Increasing cloud cover. No significant precipitation expected.SATURDAY: Freezing level hovering around 1500m. Scattered flurries, less than 5cm of snow expected. Moderate SW winds at treeline, strong SW winds at ridgetop. Overcast.
Avalanche Summary
On Tuesday cornice failure triggered a size 3 avalanche on a North facing feature at 2700m. No new observations from Monday. On Sunday a very large (size 3) deep persistent slab failed naturally on a steep glacial feature at 2500m. It's presumed that this failed on early season basal facets.
Snowpack Summary
Surface hoar is beginning to form on top of the 15-30cm of new snow that fell last weekend. This snow remains dry on high elevation polar aspects but is quickly turning moist everywhere else. Moist snow exists underneath this most recent storm snow in most of the region.Two significant persistent weak layers composed of crust and facets exist in the snowpack. Mid-March is down 40 to 80cm below the surface and Mid-February is down 80 to 200cm. Avalanche activity on these weak layers has tapered off, but snowpack tests indicate that these layers may still be sensitive to triggering. Down at the bottom of the snowpack a weak layer of basal facets exists. Large loads like cornice/ice fall or even sustained warming could initiate an avalanche on this very deeply buried weak layer.
Problems
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.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.