The primary concern Monday is wind slabs in alpine terrain immediately lee of ridge crest and fragile cornices. Be cautious as you poke out into wind affected terrain.
Confidence
Low - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A weak pacific storm system is expected to bring unsettled conditions with light flurries to the region over the next few days. On Sunday overnight and Monday, light flurries are possible but should not yield more than a couple centimeters of new snow. Treeline temperatures are forecast to peak around -5C and alpine winds are expected to be moderate to strong from the SW. Light intermittent flurries may continue Monday afternoon but sunny breaks are also possible. There is a lot of uncertainty for Tuesday and Wednesday with one model showing mainly dry conditions and another showing 10cm of snowfall. Freezing levels are being forecast to be anywhere from 500m to 1500m. With the current weather uncertainty, be sure to watch the weather forecast closely over the next few days. The Mountain Weather Forecast at www.avalanche.ca/weather is published each morning at 4am so check it out before you head out for the day.
Avalanche Summary
No new avalanches were reported over the weekend but sluffing is expected to have occurred on steep south facing slopes. On Friday control work produced loose dry avalanches to size 1 on E and NE aspects. On Wednesday control work produced a size 2 storm slab on a high elevation east facing feature.
Snowpack Summary
Recent mild temperatures have helped the surface snow to settle a bit, at least at upper elevations. The upper snowpack consists of around 40 cm of old settled storm snow that rests on 10 cm of cold facets. This interface has been producing moderate to hard shears in recent snowpack tests. In wind exposed terrain you're likely to find pencil hard wind slabs sitting on the facets, but out of the wind the old storm snow remains largely unconsolidated. Our field team was out traveling around the region last week and they found surprisingly little wind effected snow. It sounds like the story is a little different around Castle Mountain where upper elevation terrain has seen quite a bit of recent wind out of the west and now north.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.