Snow and wind have joined forces to give us a touchier snowpack that what we are used to. Conservative terrain is recommended for the next while.
Weather Forecast
Mainly cloudy tomorrow with little forecasted snow. Don't be surprised if we do get small amounts of fresh snow near the divide. Temperatures will continue to hover around -11. Winds are the real story, expect steady alpine winds of 70 km/hr with significantly higher gusts .
Avalanche Summary
2 separate incidents to talk about today:1) Forecasters remotely triggers a Sz 2 in alpine terrain. As the team walked on the top of a ridge, they triggered a small cornice chunk(10m away) that went on to release the storm slab below. The slab itself was up to 40cm thick and entrained a large amount of snow as it traveled. East aspect, 2400m, a short steep slope with a large fetch.2) A party of 3 scramblers triggered a Sz 2 slab in alpine terrain and went for a ride. Details are largely unknown, but it occurred in typical front range mixed scree/snow terrain near Wind Tower.
Snowpack Summary
Strong alpine and treeline winds have transported a huge amount of snow. Any new snow that fell has been blown into storm slabs. Even the older facetted snow has been blown around to create fresh windslabs. Areas near the divide (Burstall Pass) saw up to 20cm of new snow in the last 24-48 hours. When that fresh snow is combined with wind, slabs up to 60cm thick are common. Open areas at treeline and alpine have a widespread windslab problem and alpine areas have an additional storm slab problem in immediate lees(easterly aspects). It feels as though we are on the verge of a small natural cycle. These slabs appear to be running on the older windslabs, but quickly involving the midpack facets. The mid pack is weak enough that entrainment after the initial failure is a real concern.
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.
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.
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.