Avalanche Forecast

Issued: Apr 26th, 2019 3:41PM

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

Avalanche Canada jsmith, Avalanche Canada

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Last Avalanche Forecast for the season. For additional information check out our Spring Conditions page at: https://goo.gl/cpx8Dq

New snow and moderate winds from a variety of directions may form touchy wind slabs reactive to human triggers.

Summary

Confidence

Low - Forecast snowfall amounts are uncertain

Weather Forecast

FRIDAY NIGHT: Cloudy with flurries; 3-5 cm. / Strong, westerly winds / Alpine low -6 C / Freezing level 1400 m.

SATURDAY: Snow; 5-15 cm. / Light, westerly winds / Alpine high -3 C / Freezing level 1400 m.

SUNDAY: Mix of sun and cloud / Light, northeasterly winds / Alpine high -2 C / Freezing level 1500 m.

MONDAY: Mix of sun and cloud / Light, northwesterly winds / Alpine high -2 C / Freezing level 1500 m.

Avalanche Summary

On Thursday, a naturally triggered size 2 wind slab stepped-down and triggered a much deeper weakness on glacier ice, resulting in a size 4 avalanche. It was on a north aspect at 2850 m. in the Battle Range.

On Wednesday, a group near Campion Peak, east of Revelstoke reported a large collapse of what they suspected was a weak layer near the base of the snowpack, and propagated for around 100 m. It was on west facing slope at 2500 m.

There are currently very few professional observers submitting daily observations. Please submit your observations to the MIN. Photos of avalanches or current conditions are particularly useful.

Snowpack Summary

5-15 cm. of recent snow has been re-distributed by strong winds from varying directions, creating fresh winds slabs on all aspects at treeline and above. These slabs sit on a crust everywhere except high north facing terrain, where they overlie dry snow. Older wind slabs created by last week's storm may still linger in lee terrain below ridgetops. A layer of surface hoar (weak, feathery crystals) in the upper snowpack could still be reactive to human triggers in isolated locations such as high elevation, north facing terrain.

Below treeline, snow is disappearing rapidly.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow and moderate winds from a variety of directions may form touchy wind slabs reactive to human triggers.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Pay attention to changing conditions with elevation/aspect.
  • Use small slopes without consequence to test the bond of the new snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Any appearance of the strong April sun can initiate a loose wet avalanche cycle. The likelihood of loose wet avalanches increases as temperatures warm through the day and/or if the sun comes out for a prolonged period of time.

  • Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
  • A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.
  • Cornices become weak with daytime heating, travel early on exposed slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 27th, 2019 2:00PM