Danger levels will rise today as we finally start seeing new snow accumulate. Keep your trip plan flexible and incorporate all evidence of unstable snow (avalanche activity, cracking, whumphing, etc.) in your decision making.
Weather Forecast
5 to 15cm on snow are forecast for the park this afternoon and evening as a fast moving westerly flow brings seasonal temperatures and southwest ridge top winds 30 to 50km/h. Another system is expected to bring more snow overnight Thursday into Friday. Exact timing and amounts are uncertain. Temperatures will remain seasonal (-10 to -5)
Snowpack Summary
New snow overnight has covered a variety of surfaces including, small surface hoar and sun crust on steep south through west slopes. Widespread wind effect is present in open areas at treeline and in the alpine, though stubborn to rider triggering.Jan 4th SH/CR down 45-65 cm reacting in stab tests (moderate to hard range) yesterday at TL, SE asp.
Avalanche Summary
We have observed few natural avalanches in the park recently. These avalanches have been small and triggered by wind deposited snow or solar radiation inputs.
Confidence
Intensity of incoming weather systems is uncertain on Wednesday
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.