Avalanche danger can rise very quickly with warming and solar radiation. Be aware of changing conditions and overhead hazards. Terrain choices and timing can be critical.
Weather Forecast
An upper level ridge will keep the region fairly dry and sunny. Solar radiation will be strong, and freezing levels could rise as high as 2500 m by Sunday.Friday: A mix of sun and cloud with isolated flurries. Ridgetop winds light from the West. Freezing levels rising to 1500 m.Saturday: Sunny skies. Alpine temperatures rising to 2.0 degrees. Ridgetop winds moderate from the North. Freezing levels rising to 1500 m.Sunday: Sunny. Alpine temperatures high of 7.0 degrees. Freezing levels rising to 2500 m then dropping overnight. Ridgetop winds light from the SW.
Avalanche Summary
Cornices have started to fail with warmer temperatures and sunny skies up to size 2-2.5, without pulling deeper slabs on the slopes below. Numerous loose wet avalanches occurred up to size 2 on steeper solar aspects.
Snowpack Summary
A melt-freeze crust exists on all aspects up to 2200 m, and dryer snow can be found on high northerly aspects. The recent warmer temperatures have helped to strengthen and settle the upper snowpack, especially on solar aspects. Isolated wind slabs have formed and are sensitive to rider triggers, especially on slopes with a buried crust. Large sagging cornices are looming over slopes and pose a threat, especially when the sun comes out.Snowpack tests are producing moderate shears down 15 cm failing on surface hoar below the early April crust and hard resistant planar shears on the late March crust.Several persistent weak layers exist lower in the snowpack. The mid-March interface down 80 -110 cm, the early-March layer is down about 100-150 cm and the early February layer is now down close to 200 cm. These layers are largely dormant at this time; however, they should remain on your radar as we transition into a warm-up with minimal overnight refreeze and intense solar output.
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.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.