If you have been out in the mountains, please consider reporting your observations to the Mountain Information Network (MIN).
Weather Forecast
Freezing level dropping to valley bottoms overnight. 2-3 cm of new snow combined with light winds overnight. Overcast with light precipitation on Tuesday combined with light winds and freezing levels rising up to 1500 metres. Chance of broken or scattered cloud on Wednesday with a good overnight freeze. The next pulse of stormy weather moving into the region on Wednesday night. Warm, wet, and windy on Thursday.
Avalanche Summary
A few small natural avalanches and a couple of size 2.0 explosives controlled avalanches were reported on Sunday. Natural wind slabs and storm slabs up to size 2.5 were reported on Saturday. Natural and explosives controlled avalanches up to size 2.5 were reported on Friday.
Snowpack Summary
Strong southerly winds have developed wind slabs in the alpine and at treeline. The 20-40 cm of recent storm snow is bonding poorly to a melt-freeze crust on previously sun-exposed slopes and lower elevation terrain, and/or a layer of surface hoar on shady and sheltered slopes at treeline elevations. The surface hoar and/or crust layer buried in mid-February is now down 50-80cm. The early January surface hoar/facet layer is typically down 70-120cm. Triggering an avalanche on this layer has become unlikely but it still has isolated potential to produce very large avalanches with a heavy trigger. In general, the lower snowpack is well settled and strong, apart from some thin snowpack areas where basal facets exist.
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.