Fresh wind slabs have formed and will be reactive to human triggers at higher elevations.
Confidence
High - Due to the number and quality of field observations
Weather Forecast
MONDAY: Cloudy with sunny periods, light west winds, alpine temperatures around -6 C.TUESDAY: Sunny, moderate northeast winds, alpine temperatures around -8 C.WEDNESDAY: Sunny, moderate northeast winds, alpine temperatures around -12 C.
Avalanche Summary
Numerous small wind slabs were reactive to human triggers on northerly aspects over the weekend (in the size 1-1.5 range). Wind slabs will likely continue to be reactive to human triggers in the lee of exposed terrain the next few days.
Snowpack Summary
Light flurries with strong southerly winds have formed fresh wind slabs in the lee of exposed terrain. About 5 cm new snow sits above a thin breakable sun crust and isolated pockets of surface hoar, potentially creating weak interfaces for wind slabs to propagate along. Old lingering wind slabs may also exist in the immediate lee of ridges. A total of 60-120 cm of settled storm snow now forms our upper snowpack and has generally bonded well to the crust below. The exception may be thin rocky areas. The mid and lower snowpack are generally well settled but still feature a number of facet and crust layers that warrant long term monitoring.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.