Watch for signs of changing stability as the temperature rises during the day.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A warm, wet storm system will reach the coast early Monday. The interior should remain mostly dry for Monday but light flurries/showers are possible in the afternoon. Temperatures will rise rapidly on Monday with the freezing level reaching around 1500m and winds increasing to moderate in the alpine. On Tuesday, the Purcells region will begin to see precipitation (3-6mm) and the freezing level are expected to rise to 2000m or higher. Wednesday is expected to be similar with freezing levels around 2000m and precipitation (5-10mm). Strong alpine winds from the SW are expected for both Tuesday and Wednesday.
Avalanche Summary
Report of an isolated size 1 wind slab triggered by a ski cut in a steep gulley.
Snowpack Summary
New snowfall sits on a layer of surface hoar. Another 15-20cm below this you may find a hard rain crust. In the Golden area this crust exists up to around 1600m, whereas in the south it is up to 2000m or higher. In total, last week's storm produced slabs up to 1m thick in the north of the region and around 60cm thick in the south. This slab sits on the mid-November weak layer (surface hoar, facets, and/or a crust). Below this you will likely find a 15-20cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. The reactivity of these layers may be slowly diminishing, but they still warrant cautious consideration. Snowpack tests are getting hard pops and drops results, indicating the potential for large propagation and large avalanches.
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.
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.