Tricky conditions persist due to a weak layer in the top 50 cm of the snowpack. This layer is widespread, but is more reactive in specific terrain features. Careful evaluation is required. Watch for large cornices, and warming during sunny breaks.
Weather Forecast
An upper trough will pass through the area today, maintaining overcast skies and a chance of flurries. Temperatures remain mild with light NE winds shifting to SW. On Wednesday, a ridge of high pressure will move in bringing clearing skies and sunshine. Another front will move in on Thursday.
Snowpack Summary
Hard and Soft slabs overly a weak layer of surface hoar, now buried 50-60cm. This surface hoar is best preserved and reactive between 17-1900m, and is most reactive on solar aspects where it rests on a buried sun crust. RB scores of 2 (whole block), and wide avalanche propagations confirm that this layer is becoming touchier as it matures.
Avalanche Summary
In the park, avalanches to size 3, including one glide avalanche, were observed along the highway corridor. One avalanche was observed below lookout col, shallow (30cm), but very wide propagation. Several loose snow slides were noted on solar aspects. Near neighbors have reported many avalanches on the Feb. 12 surface hoar layer.
Confidence
Due to the number of field observations
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.