A natural avalanche cycle is expected if the weather forecast comes true. Extensive wind loading is ongoing due to West winds in the 100km/h range. Conservative route selection is advised.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Up to 15cm of snow is expected on Tuesday with winds out of the west expected to reach 105km/h. Temperatures remain generally mild. By Thursday a clearing and cooling trend is expected.
Avalanche Summary
A few naturally triggered avalanches up to size 1.5 have occurred in steep cross-loaded gully features in the past 48hrs. It is likely that these avalanches were triggered by intense wind loading.
Snowpack Summary
5 to 10cm of new snow has fallen in the past 48hrs. This snow is being rapidly re-distributed by extreme winds out of the SW. Storm slabs are forming at all elevations and are touchy to triggering in lee and cross-loaded features. Some cornice growth has also been observed.
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.
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.