Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Monday
Weather Forecast
Monday: Overcast conditions with moderate to heavy snowfall developing late in the day / Moderate southwest winds / Freezing level at 1200mTuesday: Moderate to heavy snowfall / Moderate to strong southwest winds / Freezing level at 1300mWednesday: Heavy snowfall / Moderate southwest winds / Freezing level at 1700mNote: The bulk of the precipitation is expected to fall in the south of the region for the forecast period
Avalanche Summary
Before the weekend a size 2.5 slab avalanche was observed above the Squamish River Valley on an east aspect at 2300m. The size of this slide suggests it may have failed on the February 20th interface. On Saturday loose wet avalanches to size 1.5 were reported, one of which triggered a size 2 storm slab in south facing alpine terrain. These occurred in response to solar warming. A few size 1 windslabs have also been reported. These formed from strong southwest winds on Saturday.
Snowpack Summary
Dribs and drabs of recent snowfall have been shifted by strong southwest winds into touchy new windslabs in exposed areas. In more sheltered terrain, surface hoar and/or surface facets are likely to exist. A sun crust has formed on south facing terrain.Between 60 and 110cm below the surface is a layer surface hoar which was buried on February 20th. Although this layer has a history of producing large avalanches, triggering this layer has now become difficult, and would most likely require a very large trigger on a steep, unsupported slope.Below this interface, the snowpack is strong and well settled.
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.