A persistent slab problem requires diligence and a conservative mindset.
Northerly wind may form wind slabs on southerly slopes. Where slabs form, they could be particularly touchy if they rest on a hard melt-freeze crust.
A weak layer of faceted grains above a hard melt-freeze crust may be found around 30 to 60 cm deep. This layer continues to produce large avalanches that have the potential to propagate far. It is most likely to be triggered on northwest to northeast aspects at treeline and alpine elevations.
MONDAY NIGHT: Cloudy with isolated flurries, trace accumulation, 10 km/h north wind, alpine temperature -4 C, freezing level 1300 m.
TUESDAY: Clear skies with no precipitation, 20 km/h north wind, alpine temperature -9 C.
WEDNESDAY: Clear skies with no precipitation, 10 km/h northeast wind, alpine temperature -13 C.
THURSDAY: Mix of sun and cloud with no precipitation, 10 km/h west wind, alpine temperature -8 C.
The weekend saw various avalanche types, including some wind slabs at high elevations, many small wet loose avalanches, and a few persistent slab avalanches. The most concerning avalanches are the persistent slabs, which released on the weak layer described in the Snowpack Summary. The avalanches occurred on north to northeast aspects in alpine terrain. They avalanches propagated far, around 200 to 300 m.
Looking forward, it remains possible that persistent slab and wind slab avalanches could be triggered. Naturally-triggered avalanches may be on the decrease as the weather cools, but human triggering is possible.
A dusting of snow sits on a surface melt-freeze crust on all aspects below around 1500 m and on sun-exposed slopes into the alpine. Dry snow remains on shaded slopes above around 1500 m. Recent northerly wind may form wind slabs in lee terrain features at higher elevations, which may rest on the crust.
Around 30 to 60 cm deep, a weak layer of sugary faceted grains may be found above a melt-freeze crust that formed in February. This layer has produced various human-triggered and natural avalanches over the past week. Activity has been most prevalent on northeast to northwest aspects at treeline and alpine elevations. Check out this forecaster blog for more info.
There are no deeper concerns at this time.
