Touchy and growing storm slabs will keep avalanche danger elevated this week. Riding should be great, but a conservative approach is recommended. Stick to simple terrain.
Weather Forecast
THURSDAY: Periods of snow with 5-10cm of accumulation expected overnight Wednesday and throughout the day Thursday. Freezing levels reaching 1700m with strong southwesterly ridgetop winds. FRIDAY: A mix of sun and cloud in the morning with light precipitation starting late in the day. Freezing levels reaching 1800m with light to moderate southwesterly ridgetop winds. SATURDAY: Cloudy with flurries bringing another 5-10cm. Freezing levels steady around 1800m and strong southwesterly ridgetop winds.
Avalanche Summary
Reports from Tuesday include more evidence of the widespread natural storm and wind slab avalanche cycle early Monday, with avalanches up to Size 2.5. Continued isolated natural avalanche activity likely occurred on Tuesday primarily in alpine areas in response to loading from fresh snow and wind. These fresh storm and wind slabs should increase in size and sensitivity and become much more widespread as they build throughout the week.
Snowpack Summary
10-20cm of fresh snow adds to the now 30-60cm thick storm slabs, which are bonding poorly to on a crust on previously sun-exposed slopes and surface hoar on shady and sheltered slopes. Thicker and touchier wind slabs are lurking throughout exposed terrain at and above treeline. A couple sun crusts might exist in the upper 50-70cm on southerly aspects. The surface hoar and/or crust layer which was buried February 10 is now down around a metre and is still producing isolated hard sudden results in snowpack tests. Large cornices will be getting weak with warmer temperatures.
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.