Don't let sunny skies cloud your good judgement today.. a variety of hazards are present in the park, including a touchy buried persistent weak layer. Watch for solar triggered avalanches this afternoon on south through west facing slopes.
Weather Forecast
A ridge of high pressure builds in today bringing a NW flow brings cold, dry conditons. A weak inversion is forecast today with possible valley cloud and sunny conditions above.
Snowpack Summary
70cm of storm snow overlies a weak layer of buried surface hoar. The surface hoar sits on a crust which is best developed on steep S/SW slopes. The surface hoar layer was the largest in sheltered areas between 1500 and 1700m. This layer is more prominent on the eastern side of the park. This variability will make hazard evaluation tricky.
Avalanche Summary
Yesterday along the highway corridor we did not observe any new natural avalanches. However, visibility was poor. Avalanche control on Wednesday triggered numerous avalanches, mainly size 2-2.5. These avalanches primarily involved storm snow. We have had limited observations In the backcountry, however a widespread natural cycle is suspected.
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.