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Avalanche Canada mbender, Avalanche Canada

Northwest Coastal Avalanche Forecast

Apr 25th, 2019 4:53PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Loose Wet.

Limited recent field observations mean that this forecast should be used to guide your initial assessment of conditions. See our 'Cold & Snowy' spring scenario for more on managing current conditions.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

Thursday Night: Cloudy with flurries bringing approximately 5-10 cm of new snow. Light to moderate south winds. Alpine high temperatures around -6 with freezing levels to 800 metres.

Friday: Cloudy with flurries bringing approximately 5-10 cm of new snow. Light to moderate south winds shifting southwest. Alpine high temperatures around -5 with freezing levels to 1000 metres.

Saturday: Sunny with cloudy periods. Light northeast or northwest winds. Alpine high temperatures around -3 with freezing levels to 1300 metres.

Sunday: Mix of sun and cloud. Light northeast wind. Alpine high temperatures around -3 with freezing levels to 1200 metres.

Avalanche Summary

Reports from the Bear Pass area on Wednesday showed a few new size 2 (large) wind slab releases observed in steep leeward features in the alpine.

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

Please submit your observations to the Mountain Information Network.

Snowpack Summary

Up to10 cm of new snow fell over Tuesday night, adding to 10-30 cm of new snow that fell Sunday night and Monday. Moderate to strong southwest winds are expected to have formed reactive wind slabs with much of this recent snow. The new snow sits on an older layer of settled storm snow from last week, which itself overlies a now 40-60 cm-deep melt freeze crust. This crust is widespread with the possible exception of high elevation north aspects. Most of the recent precipitation has fallen as rain at 1000 m and below.

At lower elevations, ongoing warm weather has been promoting isothermal snowpack conditions and melting the snowpack away.

Problems

Wind Slabs

Recent snowfalls coupled with bouts of strong southwest wind have likely developed new wind slabs at higher elevations. Expect snow amounts and the effects of wind loading to increase as you gain elevation.

  • Be cautious as you transition into wind affected terrain.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects:

North, North East, East, South East.

Elevations:

Alpine, Treeline.

Likelihood

Likely - Possible

Expected Size

1 - 2

Loose Wet

Rain at lower elevations will weaken the surface snow layers and increase the likelihood of sluffing in steep terrain where there is still enough snow to avalanche i.e. treeline and the upper end of the below treeline elevation band.

  • Use caution above cliffs and terrain traps where small avalanches may have severe consequences.

Aspects:

All aspects.

Elevations:

Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Apr 26th, 2019 2:00PM