Avalanche Forecast Kootenay Boundary

Date Issued: Valid Until:

Avalanche Canada jsmith, Avalanche Canada

Avalanche Forecast

Sun Apr. 21st ยท 4:13PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Wet Slabs Wet 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 Moderate

Below Treeline

Danger Ratings Low

Forecast high freezing levels overnight means the hazard may elevate quickly if the sun comes out on Monday.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

SUNDAY NIGHT: Clear / Light, southwesterly winds / Alpine low 4 C / Freezing level 2400 m.

MONDAY: Mix of sun and cloud / Moderate, southwesterly winds / Alpine high 7 C / Freezing level 2500 m.

TUESDAY: Rain to mountain-tops; 5-10 mm. / Moderate, southwesterly winds / Alpine high 7 C / Freezing level 2500 m.

WEDNESDAY: Sunny / Light, westerly winds / Alpine high 6 C / Freezing level 2400 m.

Avalanche Summary

On Saturday, natural and skier triggered loose wet avalanches to size 1.5 were reported on all aspects at treeline and above.

On Tuesday, a party skiing near Kootenay Pass reported "whumphing" on solar aspects near ridgetops and triggered a size 2 storm slab avalanche sitting on a crust on a north aspect at around 2000 m. See the MIN report HERE.

Snowpack Summary

Rain to mountain-tops Thursday night soaked 20-40 cm of recent snow and initiated a loose wet avalanche cycle at treeline and above on Friday. Below treeline, the snow is isothermal (0 C throughout the snowpack) and disappearing rapidly.

As temperatures cool, we will enter a diurnal cycle during which the hazard will be low in the mornings, if there was a strong overnight freeze, and elevate throughout the day depending on warming and solar radiation. Hazard ratings are for the peak hazard expected during each day.

Problems

Wet Slabs

Wet Slabs

If temperatures remain warm, wet slabs releasing on crust layers are still possible.

  • If the snow is wet, mushy, or feeling bottomless, its time to go home.
  • Pay attention to changing conditions with elevation/aspect.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2
Loose Wet

Loose Wet

If temperatures remain warm, loose wet avalanches are still possible with strong solar radiation.

  • A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.
  • Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5