A conservative approach is critical as Sundays storm increases the load on a variety of weak layers in our complex snowpack.
Summary
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain on Sunday
Weather Forecast
Synopsis: Snow should start falling in earnest around supper time Saturday evening. Look for it to snow through Sunday night accompanied by strong SW winds. In the wee hours of Monday morning the flow begins to take a more northwesterly tilt which eventually leads to ridging and clearing on Monday/Tuesday. Saturday Night: Freezing Level: 1400m - 1900m; Precipitation: 6:12mm - 6:20cm; Treeline Wind: Moderate, SW | Extreme SW at ridgetop.Sunday: Freezing Level: 1300m - 1800m; Precipitation: 3:8mm - 4:15cm; Treeline Wind: Moderate, SW | Strong SW at ridgetop.Monday: Freezing Level: 1200m; Precipitation: 0:3mm - 0:5cm; Treeline Wind: Light, NW | Moderate NW at ridgetopTuesday: Freezing Level: 1500m; Precipitation: Nil; Wind: Light, SW
Avalanche Summary
On Friday we received a report of storm snow failing as a fast moving size one avalanche that ran on the March 13th crust on a steep north facing slope at treeline. There was also a report of a size two avalanche that was triggered accidently on a North facing slope, again at treeline, on the early March surface hoar/crust combo. On Thursday explosive control produced avalanches to size 3 on both SE & NE facing slopes in upper treeline and alpine elevations. A skier remote triggered a size 3 avalanche from 100m away on a NE facing slope at 2200m. The avalanche was triggered from low angle terrain and resulted in a very large avalanche with a crown up to 150cm in depth. Last Saturday's avalanche fatality occurred in the Keefer Lake area northeast of Cherryville. The avalanche, which occurred in a cut block at about 1700m, involved 3 sledders who were in a party of 6. Two of the men were able to inflate their airbags and were partially buried. The deceased was reportedly not able to inflate his airbag, and was buried approximately 5m below the surface.While not in this region, it's worth taking a look at last weekends
incident from the Cariboos.
Snowpack Summary
The surface is currently a mix of 3 - 6mm surface hoar and crust. Last weeks storm snow has settled into a 50 - 100 cm slab that rests on the early March interface consisting of small grained surface hoar in sheltered areas and a sun crust on solar aspects. In upper elevation wind exposed terrain the new snow has been pushed into deep wind slabs by moderate SW winds.The last week featured an average daytime freezing level around 1800m which resulted in a daily melt freeze cycle that left many features wet and sloppy by the afternoon. This setup resulted in some serious incidents recently.Ridgetop cornices remain large and unsupported.The February 10th surface hoar/facet/crust combo is 80cm - 250cm below the snow surface and widespread throughout the region. Surface avalanches in motion and cornice fall still have the potential to initiate an avalanche on this deeply buried weak layer. Remote triggering on this layer is ongoing. The mid and lower snowpack are strong and well consolidated.
ghelgeson,
Avalanche Canada
