Avalanche danger will be higher when slopes are directly in the sun. Play close attention to overhead hazards; slopes or cornices may fail when receiving strong solar. Loose solar triggered avalanches, or cornice failures may step down deeper.
Weather Forecast
It's clear and calm this morning. Expect solar triggered avalanches, starting on E aspects and following the sun. A cold front will move in this afternoon bringing increasing cloud and rising SW'ly winds. Tuesday should be mostly cloudy, with light winds and flurries. On Wednesday, another upper ridge builds bringing sunny periods.
Snowpack Summary
A very soft slab exists over a thin crust down ~30cm and a widespread surface hoar layer down ~50cm. The surface hoar is most reactive where it is largest; between 1700-1900m; or on steep solar aspects where it sits on a crust. Tests indicate it is likely to be triggered by light loads (easy to moderate, planar/collapses and RB2 whole block).
Avalanche Summary
Clouds reduced solar effects yesterday. When the sun did hit slopes, several size 1.5-2 solar triggered avalanches occurred. There have been human triggered avalanches up to size 2 on the most recent surface hoar layer. These have occurred on all aspects and elevations, with the avalanches propagating up to 300m wide and traveling fast and far.
Problems
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.
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.