Avalanche Forecast

Fair - Freezing levels are uncertain for the entire period

On Wednesday the region sees the last drips and drabs of precipitation for a while. A strong ridge building from the western part of the province will bring dryer conditions for the forecast period. On Thursday ridgetop winds will be light from the NW; freezing levels may rise to 1200m and alpine temperatures steady near -5. Friday and Saturday the ridge of high pressure holds true with freezing levels potentially reaching 1800m.

On Tuesday very little natural slab avalanche activity occurred. One report of a natural size 2 slab avalanche occurred on a cutbank @ 800m, on a 35 degree North aspect. Reports indicated natural sluffing from steep rocky features, and skier triggered sluffing within the recent storm snow, up to size 1.5. What did catch my eye was two separate reports of size 3 slab avalanches. The reports came in from Southern parts of the region. The actual avalanches were unobserved, but details revealed crown sizes 150cms deep, which could possibly be the mid-January SH/FC layer. One slide initiated from a steep gully feature and triggered the slope below at 1700m. The other slide reportedly took out mature timber. These both occurred on NE-E aspects. Cornice fall may increase later in the week due to warming temperatures, which may provide large enough triggers on slopes below.

Storm slabs up to 60cms thick developed over the weekend at all elevations. Wind slabs have formed on North through East slopes in the alpine and at treeline. Buried below the storm snow seems to be a fairly settled mid-pack, with a couple lingering layers.We continue to monitor the January 13th surface hoar/facet layer, and the January 25thlayer. Recent snowpack field tests have shown generally moderate results, including resistant planar shears. I suspect the snowpack is settling out, and generally bonding above these. With warming temperatures forecast we may start to see these mid-January layers become reactive, producing large avalanches. Recently there have been two reports of large avalanches (size 3) that have crown depths of 150cms. I suspect these may have occurred on this layer but have no solid evidence to back it. The average snowpack depth at 1700m is 2-3 m.