Avalanche Forecast

Fair - Intensity of incoming weather is uncertain on Sunday

Saturday: light to moderate snowfall / moderate northwest winds increasing in the evening / freezing level at 800mSunday: moderate snowfall / moderate to strong southwest winds / freezing level rising to 1300mMonday: light snowfall / light to moderate westerly winds / freezing level at 1100m

A size 2 natural fresh windlsab avalanche was reported in the Nelson area on thursday. It ran 200m and occurred on a north aspect at treeline. Explosives control in the area also produced numerous size 1-1.5 avalanches with crowns ranging from10-60cm.

Significant snowfall and strong to extreme winds earlier in the week created extensive windslabs in the region. In some parts of the region this windslab is sitting on a freezing rain crust that developed on Tuesday morning. Although it's reasonable to think that these windslabs have started to strengthen somewhat, the combination of more recent light snowfall and moderate winds have continued to create fresher windslabs at ridge top. It should also be said that snowfall accumulations over the past few days have been quite variable throughout the region with with 24hr snowfall amounts on Thursday morning ranging from 2cm to 29cm. Reactivity on the aforementioned crust (which sits about 25cm below the surface in wind-neutral areas) may develop with increased load forecast for Sunday. Layers of concern deeper in the snowpack include a surface hoar/facet layer from mid-December and weak basal facets at the base of the snowpack in shallow snow areas. These layers have become less of a concern in the vast majority of locations. Last Saturday the mid- December layer is thought to have failed in several large avalanches that occurred in the Bonnington Range. This is a lingering layer of concern that reflects low probability but high consequence. Snowpack depths in the region are around 240 cm.