Regions
South Coast Inland.
New snow and wind continue to create touchy storm slabs reactive to human triggers, especially in wind effected areas at treeline and above.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
SATURDAY: 10-20 cm of new snow / Moderate to strong southwesterly ridgetop winds / Freezing level rising to around 1000m.SUNDAY: 10-20 cm of new snow / Strong southwesterly ridgetop winds / Freezing level rapidly rising to around 1800m.MONDAY: 10-20 cm of new snow / Strong southwesterly ridgetop winds / Freezing level around 1800m.
Avalanche Summary
Two natural storm slab avalanches stepped-down to facets at the bottom of the snowpack and resulted in 3-3.5 avalanches. They occurred on north and south aspects between 2000 and 2250 m. The extended period of continuous loading of the snowpack may begin to reactivate deeply buried weak layers resulting in large and destructive avalanches running full path.
Snowpack Summary
15 cm of new snow on Friday morning brings recent storm totals to 70-100cm. Moderate southerly winds continue to redistribute the new snow. Last weekend's strong to extreme southeasterly ridgetop winds likely created dense storm slabs lurking in lee and cross-loaded features at treeline and above.90-120cm below the surface you'll likely find a few crusts that were buried during the first few weeks of January. Due to limited observations, not much is known about the current reactivity of these layers.The lower snowpack includes the mid-December crust layer. The load of the new snow may tip the balance and reactivate this layer in isolated terrain - particularly in the north of the region where it's shown prolonged reactivity in snowpack tests.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.