Avalanche Forecast Northwest Coastal

Date Issued: Valid Until:

Avalanche Canada istorm, Avalanche Canada

Avalanche Forecast

Sun Mar. 10th · 3:00PM

Alpine

Danger Ratings High

Treeline

Danger Ratings High

Below Treeline

Danger Ratings Considerable
Storm Slabs Storm Slabs
Persistent Slabs Persistent Slabs

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Considerable

Below Treeline

Danger Ratings Moderate

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Avoiding avalanche terrain or choosing "simple terrain' that is protected from the wind is both a good way to manage risk, and where you'll find the best riding.

Confidence

High -

Weather Forecast

SUNDAY NIGHT: Height of the storm:  strong southerly winds, precipitation (heavy at times). Expected storm snow accumulations near treeline varies between 40 cm closer to the coast and 15 cm in drier inland areas.MONDAY: Around 10 but maybe as much as 20 cm more snow. Precipitation ending mid-day. Freezing level around 800 m. Winds moderate from the southwest.TUESDAY: Cloudy with sunny periods. Freezing level around 800 m. Light westerly winds.WEDNESDAY:  Mix of sun and cloud. Dry. Freezing level around 500 m. Light to moderate southwest wind.

Avalanche Summary

Recent avalanches suggest the incoming storm may produce bigger avalanches than might otherwise be expected because of the relatively weak, sugary facets the new storm snow is falling on.On Saturday a small slab avalanche (size 1.5) was triggered in the facets releasing about 40 cm deep near treeline near Terrace. It didn't release wide, and didn't even run far (30 m). Two small (size 1.5) slab avalanches were triggered on Thursday, Both are thought to have released on the mid-february weak layer buried 30-50 cm below the surface.

Snowpack Summary

With a windy and reasonably intense storm arriving today (Sunday) expect reactive and widespread storm slabs and wind slabs. The incoming snow will cover previously scoured surfaces and aging hard wind slabs on all aspects in exposed terrain and sun crusts on more solar aspects. 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 sugary 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 these widespread facets to become a larger problem with additional new snow.The lower snowpack is generally considered strong.

Problems

Storm Slabs

Storm Slabs

A natural avalanche cycle with storm slabs and wind slabs is expected to begin overnight, continuing on Monday. Existing weaknesses in the upper snowpack may become activated resulting in larger avalanches than expected. See Persistent Slabs below.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.The best riding will be found in simple terrain and sheltered from the wind at or below treeline.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Certain - Very Likely

Expected Size

1.5 - 3
Persistent Slabs

Persistent Slabs

Higher new snow amounts could make any surface hoar and sugary facets in the upper snowpack the layers to watch.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Storm or wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3.5