The treeline avalanche hazard has risen. The variability and complexity within the upper snowpack makes terrain usage and snowpack observations critical. Be curious while you are traveling, don't hesitate to dig and inspect the snowpack.
Weather Forecast
Continued NW flow with valley bottom winds light, out of the west. Temperatures will be similar to today, -15 in the morning, rising to -8 in the afternoon.
Avalanche Summary
A localized natural cycle was noted on Hero's knob itself. East to South aspects had a number of slabs release. All activity was thought to be sliding on the crust. Sz 2 was the average size.
Snowpack Summary
The Hero's knob area was explored today. Below treeline, the snow pack was generally predictable and in tune with what we've been seeing for the last while: a distinct crust buried with 10cm's of new snow and a solid midpack. Treeline, was a different story all together. The snowpack was a mix of different crusts, windslabs, facets and depth hoar. The general feel was that the snowpack was variable in terms of strength and we had a hard time trusting it. The Dec13th crust was down 30cm's, and reactive(see avalanche observations). Compression tests ranged from easy to moderate with sudden plainer failures. The deeper layers were still reacting the tests, but not until the "hard" range. Snow depths at 2200m were 90-110cm's.
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.
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.