Avalanche Forecast Northwest Coastal

Date Issued: Valid Until:

Avalanche Canada cgarritty, Avalanche Canada

Avalanche Forecast

Tue Apr. 23rd ยท 3:58PM

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Wind Slabs Wind Slabs

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Recent field observations from the south of the region are scarce. Use this forecast as a starting point for assessing the depth of recent snow, its bond to the surface, and the distribution of new wind slabs.

Confidence

Low - Due to the number of field observations

Weather Forecast

Tuesday night: Clear periods. Light to moderate west winds.

Wednesday: Mainly cloudy with scattered flurries bringing 2-5 cm of new snow. Light to moderate west winds. Alpine high temperatures around -5 with freezing levels to 900 metres.

Thursday: A mix of sun and cloud. Light variable winds. Alpine high temperatures around -3 with freezing levels to 1100 metres.

Friday: Cloudy with scattered flurries bringing 2-5 cm of new snow, continuing overnight. Light southeast winds. Alpine high temperatures around -4 with freezing levels to 1000 metres.

Avalanche Summary

Reports from the Bear Pass area on Monday describe a natural avalanche cycle driven by new snow and strong winds. The cycle led with natural wind slab releases reaching size 3 (very large) in the morning and followed with wind slab releases decreasing in size and shifting to east aspects as winds became extreme and shifted west in the afternoon.

No new avalanches have been reported in the south of the region.

Please submit your observations to the Mountain Information Network.

Snowpack Summary

There may be 10-30 cm of new snow that fell Sunday night and Monday to add to the 20-40 cm of snow that fell through the last week at upper elevations. Moderate to strong southwest winds are expected to have formed reactive wind slabs. This new snow sits on a melt freeze crust except for high elevation north aspects. It is likely that the most recent precipitation has fallen as rain 1000 m and below.

A crust that formed in early April is down 30 to 100 cm on high elevation north facing slopes. Weak layers of surface hoar and facets were previously observed on this crust. At lower elevations, ongoing warm weather has been promoting isothermal snowpack conditions and melting the snowpack away.

Problems

Wind Slabs

Wind Slabs

New snow accompanied by moderate to strong southerly winds Monday likely developed new storm and wind slabs. Expect snow amounts to increase incrementally as you gain elevation.

  • Look for signs of instability. Shooting cracks and recent avalanches indicate unstable conditions.
  • Be cautious as you transition into wind affected terrain.
  • Minimize overhead exposure during periods of heavy loading from new snow, wind.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely - Possible

Expected Size

1 - 2