There is a lot of variability in the upper snowpack; skier triggering is possible on specific terrain. A rapid rise in temperatures is forecast to begin later today, and clear skies tomorrow. Avalanche danger will increase with the warmth and solar.
Weather Forecast
The warm front passage is bringing clouds, light snow, and temps will start to rise, with warmer temps in the alpine reaching -5 today. Upper level winds (3000m) are N'ly, while lower level winds (see weather stations) remain S'ly. Tues and Wed expect strong solar and winds, with alpine temps to 0. This rapid change in temp will increase danger.
Snowpack Summary
A 30-60cm slab overlies the Jan.4 persistent layer. The distribution of this layer is variable but tests and a Sa yesterday indicate it is triggerable. Our main concern is on steep S'ly slopes where facets or surface hoar overlie a crust. In sheltered areas on all aspects between 1500 and 1700m it consists of surface hoar. New windslabs have formed
Avalanche Summary
Yesterday, skiers accidentally triggered a size 2.5 avalanche while bootpacking up the SE face of Rogers. It failed on facets on the Jan 4 crust, and propagated 30m upslope. It was 35m wide, 300m long with 1-2m deep debris. One person was involved but was uninjured. There have been no new natural avalanches observed since Jan 10th.
Confidence
Timing of incoming weather systems is uncertain
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.