Avalanche Forecast Purcells

Date Issued: Valid Until:

Avalanche Canada mconlan, Avalanche Canada

Avalanche Forecast

Fri Apr. 19th ยท 4:30PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Wind Slabs Wind Slabs
Loose Wet Loose Wet

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low

You may find new wind slabs up high, likely above around 2300 m. Also keep your eyes to the skies and avoid travelling on or beneath southerly slopes during intense sunny conditions.

Confidence

High -

Weather Forecast

FRIDAY NIGHT: Clear skies, light northwest wind, alpine temperature -6 C, freezing level 1500 m.

SATURDAY: Mix of sun and clouds, light north wind, alpine temperature -4 C, freezing level 1900 m.

SUNDAY: Clear skies, light north wind, alpine temperature -2 C, freezing level 2100 m.

MONDAY: Increasing clouds, light southwest wind, alpine temperature 1 C, freezing level 2500 m.

Avalanche Summary

A natural loose wet avalanche cycle was observed on Thursday with the increasing freezing level.

Snowpack Summary

The freezing level hovered around 2300 m to 2500 m during Friday's storm. Around 10 to 15 cm of snow likely accumulated above the freezing level. The snow fell with strong southwest wind, forming wind slabs in lee terrain features. The snowpack is wet below treeline from recent rain and warm air.

Weak and sugary faceted grains may remain at the bottom of the snowpack in the alpine, producing a low likelihood but high consequence scenario. Steep, rocky areas with a shallow snowpack are the most likely places to trigger this layer.

Problems

Wind Slabs

Wind Slabs

New wind slabs may have formed above around 2300 m from recent snow and strong southwest wind. These slabs may be touchy, particularly in lee terrain features near ridges.

  • Use small, representative slopes without consequence to test the bond of the recent snow.
  • Expect conditions to change rapidly with aspect and elevation.
  • Be careful with wind-loaded pockets, especially near ridge crests.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2
Loose Wet

Loose Wet

The likelihood of loose wet avalanche activity will increase during periods of intense sun, particularly where it moistens previously dry snow at higher elevations.

  • Minimize overhead exposure and avoid steep slopes during periods of strong sun.
  • Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.

Aspects: East, South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2