Patience and diligence may be required to resist venturing into complex terrain as the snowpack settles and adjusts to the recent load and warming.
Weather Forecast
SATURDAY: A mix of sun and cloud with isolated light flurries. Freezing levels around 1200m and light southwesterly winds. SUNDAY: A mix of sun and cloud and possible isolated light flurries with freezing levels dropping below valley bottoms and light variable winds. MONDAY: A mix of sun and cloud with isolated light flurries. Freezing levels in valley bottoms and light southwesterly winds.
Avalanche Summary
Reports from Thursday include a several storm and wind slab avalanches up to Size 2 from natural and human triggers.
Snowpack Summary
Weaknesses exist within and under the recent settled storm snow, with snowpack tests producing easy to moderate results down 15-20cm (or deeper where wind-loaded) on buried surface hoar, decomposing storm snow or a thin crust, and hard results down 45-65 cm on a crust buried mid January. The persistent weak layer of buried surface hoar, sun crusts, rime crusts and/or facets that was buried in early January is now down close to a metre in most places and producing hard but sudden results in snowpack tests. The overlying slab remains primed for triggering and is especially touchy at and below treeline. The lower snowpack is well settled and strong.
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.
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.