New snowfall with high winds on Friday night will create Wind Slabs. Watch the freezing levels - the new load, and a rise in temperatures on Sunday, may also be enough to tickle a Deeply buried Persistent layer back to life.
Weather Forecast
Flurries tomorrow, followed by upto 10cm of snowfall on Friday night, then a partial clearing late on Saturday morning. Strong Westerlies rise steadily to almost 100kph Friday night, then ease through Saturday afternoon. Sunday looks dry with Moderate Westerlies. Warm temperatures, cooling Friday night, then rising to near freezing on Sunday.
Snowpack Summary
5-10cm of new snow at upper elevations has formed soft Wind Slabs, lee to Moderate Westerly winds. These are currently stubborn to human triggering. Buried below are older wind slabs, more difficult to trigger. Down 1m is a faceting rain crust. Though mainly requiring large triggers, any avalanche triggered on this would be large & destructive.
Avalanche Summary
Numerous small loose dry avalanches observed today from very steep terrain. One Size one Wind Slab observed today, at 2000m on an open, NE facing slope. On Sunday, a large, Deep Persistent slab avalanche was noted on the same slope... these are occurring on an occasional, but semi-regular, basis. They are large, and difficult to predict.
Confidence
Forecast snowfall amounts are uncertain on Saturday
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.