Forecast new snow and wind are expected to continue to develop storm slabs at all elevations. Pockets of wind transported snow may be deep and easily triggered.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Light snow (3-5 cm) is forecast overnight with moderate westerly winds and freezing levels dropping down to valley bottoms. Some flurries continuing on Thursday with moderate northwest winds and valleys temperatures rising up to about +1.0 celcius. Cloud continuing on Friday with moderate northwest winds and temperatures around -10 in the alpine. Increasing southwest winds on Saturday with increased cloud and some flurries or light snow.
Avalanche Summary
On Tuesday a couple of reports of slab avalanches size 1.0 were reported from alpine elevations. One of these slabs was remotely triggered from six metres away.
Snowpack Summary
Another 5 cm of new snow overnight makes the recent storm snow total about 10-15 cm above a variety of weak surfaces including surface hoar and facets. The upper snowpack is generally loose and unconsolidated due to the current lack of slab properties, however there is now 30-40 cm sitting on a mix of surface hoar, facets, and sun crusts that were buried January 4th. Some operations continue to track buried surface hoar from early December. While test results on deeply buried surface hoar continue to show planar results when hard forces are applied, there have not been any avalanches reported failing on this layer. I have removed the persistent weak layer problem from the front page, and we will continue to monitor reports from operators in this region. The mid and lower snowpack is generally well settled and strong.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.