Heavy loading from snow, wind and rain will cause avalanche danger to spike.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Thursday
Weather Forecast
THURSDAY: Moderate snowfall starting overnight Wednesday and continuing throughout the day with over 15cm of accumulation expected. Freezing levels briefly reaching 2000m midday, and extreme southwesterly ridgetop winds. FRIDAY: A mix of sun and cloud with light precipitation and freezing levels back up to 2000m. Winds should ease off. SATURDAY Mainly cloudy with light precipitation picking up in the afternoon. Freezing levels hovering around 2000m and strong southwesterly ridgetop winds.
Avalanche Summary
No new avalanches were reported on Monday or Tuesday. On Sunday, storm slab avalanches up to size 2 were reported from higher elevations. Expect natural wind and storm slab avalanche activity to increase with forecast heavy loading from snow, wind and rain.
Snowpack Summary
Light amounts of fresh snow has buried a widespread supportive crust. At higher elevations, touchy wind slabs linger below ridgecrests and behind terrain features in exposed terrain. Deeper in the snowpack, recent snowpack tests gave very easy sudden collapse results down 80cm on a southeast aspect at 1850m on the deep persistent facet/crust weakness from buried early December. Watch this weakness with extreme warming from sun-exposure, or warming/loading from rain. Cornices are also reported to be huge and weak.
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.