Wind slabs are the main concern, watch for loaded pockets around ridge lines. Look up when traveling on the shady side under ridges, keep in mind that the sun could be shining on the other side and weakening cornices above.
Weather Forecast
The strong ridge of high pressure is expected to hold until at least Wednesday blocking any new snowfall. Today will bring a mix of sun and cloud with freezing levels rising to 1600m and light NW winds at ridgetop. Clouds should build slowly over the next few days with small amounts of precipitation expected to begin on Wednesday.
Snowpack Summary
Below 1900m a light dusting of new snow sits on a hard crust. Up to 2200m 15-20cm of light snow sits on the Feb 18 crust/ surface hoar layer. The Feb 14 crust is down 20-25 and is up to 10cm thick. Soft wind slabs have formed on all aspects in exposed areas at treeline and above. Persistent weak layers down 1-1.5m are stubborn to trigger.
Avalanche Summary
1 Size 2 loose wet avalanche was observed yesterday in the highway corridor from 2590m on a South aspect. There were reports yesterday of a large cornice fall (Size 3) off the north face of Bonney that didn't trigger a slab.
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.
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.