South Columbia

Fair - Timing, track, or intensity of incoming weather is uncertain

Initially, the approaching frontal system will spread light-moderate precipitation amounts with rising freezing levels. Towards the end of the forecast period a cooling, drying trend will take place before the big warm-up next week.Friday: Overcast with light precipitation amounts. Ridgetop winds will blow moderate from the SW and freezing levels will rise to 2000 m.Saturday: Overcast with moderate precipitation amounts. Ridgetop winds will blow moderate from the NW and freezing levels near 1600 m then falling to valley bottom overnight.Sunday: Mix of sun and cloud with a cooling, drying trend. Freezing levels will rise to 1200 m by the afternoon.

On Wednesday, no new avalanche activity was reported.On Tuesday, a couple of large, older (past 48hrs) slab avalanches size 2-3 were spotted from the flanks of Albert Peak. Crown depths were approximately 50 cm deep and the suspect failure plane may have been the early April surface hoar. In neighboring Glacier National Park, skiers triggered a size 3 slab on a buried crust on an east aspect in the alpine on Monday.

Over the past 2 days, melt-freeze crusts have formed on solar aspects. North aspects remain dry, with new surface hoar development and surface faceting. Forecast snow and wind will likely build new wind slabs and bury an older wind slab problem found at treeline and above. Cornices are very large and remain a concern, threatening slopes below.A weak interface down about 60-120 cm consists of a crust on solar aspects, and surface hoar on high-elevation northerly aspects. Snowpack tests are showing easy-moderate sudden planar compression results in the North Columbia’s. This may be comparable to some areas through-out the South Columbia region. Earlier this week, very large avalanches occurred in this region and in the neighboring Glacier National Park.