The upper snowpack is touchy and complex. Layers in the top meter are sensitive to human triggering and large, natural avalanches continue to occur.
Weather Forecast
Today expect a mix of sun and cloud, with alpine temps reaching -1'C and light but gusty westerly winds. On Wed a warm storm system will bring scattered flurries with freezing levels at 1700m. By Thurs freezing levels are forecast to rise to 2600m with wet flurries, alpine temps to +4'C and moderate to strong SW winds.
Snowpack Summary
50cm of snow fell in the past 5 days fell above 1800m and is settling rapidly into a slab. The upper 50cm is a complex mix of crusts, facetted snow and surface hoar which have been reactive to skier triggering. The mid Feb crust/facet/surface hoar layer is down ~75cm and is easily triggered at treeline. Cold temps overnight formed 7cm crust.
Avalanche Summary
In the park yesterday a field team found touchy conditions on northerly aspects at treeline. Convex rolls were reactive to ski cuts, triggering 65cm deep slabs. Loose snow sluffing off cliffs has been triggering similar deep slabs. Yesterday on a SE aspect, ~2200m on Mt Catamount 2 size 2.5-3 natural avalanches occurred.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
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.
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.