Avalanche Forecast

Issued: Mar 9th, 2019 3:25PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Persistent Slabs.

istorm, Avalanche Canada

Northwest Coastal.

Uncertainty about expected storm snow amounts means avalanche activity could be larger and run farther than one might normally expect. Use increased caution if more than 30 cm of new snow accumulates.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

SATURDAY NIGHT: No precipitation. Calm winds.SUNDAY: Snow developing with 15 to 30 cm new snow. Freezing level around 500 m. Winds increasing to moderate or strong from the south.MONDAY: Around 10 to 20 cm new snow. Freezing level around 800 m. Winds light to moderate from the southwest.TUESDAY: Cloudy with sunny periods. Freezing level around 800 m. Light westerly winds.

Avalanche Summary

No new avalanches reported Friday. Two small (size 1.5) slab avalanches were triggered by separate ski groups on Thursday, one on a northwest aspect at 1250 m and one on a northwest aspect at 1500 m. Both are thought to have released on the mid-february weak layer buried 30-50 cm below the surface.

Snowpack Summary

Scoured surfaces and aging hard wind slabs can be found on all aspects in exposed terrain after a prolonged period of outflow winds. South facing slopes have sun crusts on the surface.The upper- and mid-pack is weakening with continued cold temperatures so there are widespread areas with soft faceted snow, and possibly surface hoar. This sugar soft snow has been reactive in some snowpack tests and there have been some small slab avalanches noted on this layer. There is potential for this layer to become a larger problem with additional new snow.The lower snowpack is generally considered strong.

Problems

Storm Slabs

Weather forecasts differ on the amount of storm snow to expect. Higher storm snow accumulations could result in larger avalanches running on a lower layer. (see below).

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Use caution on open slopes and convex rolls Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Persistent Slabs

Higher new snow amounts could make the February surface hoar and sugary facets the layer to watch. Recent avalanche activity suggests the most likely place to trigger an avalanche is on a shady convex slope at treeline.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, West, North West.

Elevations: Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 10th, 2019 3:00PM