South Columbia

Recently formed wind slabs are expected to be touchy on Tuesday. Use extra caution in wind exposed terrain and watch for signs of recent wind loading in leeward and cross-loaded terrain features.

High -

A high of pressure is forecast to keep the region cold and dry for the next several days. On Tuesday, mostly sunny conditions are expected with light to moderate northeast wind in the alpine and treeline temperatures around -15C. Wednesday and Thursday are forecast to be sunny with light northeast wind in the alpine and treeline temperatures remaining around -15C.

On Sunday, a natural cornice released triggered a size 1.5 wind slab in the Monashees on an east aspect at 2100 m elevation. Four natural wind slab size 1-2 were observed in the Selkirks and skiers triggered five size 1 wind slabs. Most of these were on north through east aspects in the alpine and slabs were typically 10-30 cm thick. On Saturday, one natural and a few skier triggered wind slabs were observed. One of these was remotely triggered from 20 m away. The typical slab thickness in these avalanches was 10-15 cm. On Tuesday, recently formed wind slabs are expected to remain reactive to human triggering. Winds have recently switched from south to north and wind slabs should be expected on all aspects.

Recent strong shifting winds have formed wind slabs on a variety of aspects in wind exposed terrain. A new sun crust is being reported on steep solar aspects. The mid-January interface is now down 20-50 cm and consists of buried surface hoar in sheltered areas, sun crust on south aspects, and/or widespread faceted old snow. The interface has generally stabilized but isolated weaknesses may still exist where buried surface hoar is preserved.