Avalanche Forecast

Issued: Apr 7th, 2023 11:30AM

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

Avalanche Canada ahanna, Avalanche Canada

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The most likely place to trigger an avalanche is on leeward slopes in the alpine where new and recent snow has been wind-loaded into reactive slabs.

Summary

Confidence

Moderate

Avalanche Summary

Wind slabs and cornices have been reactive in the past few days. Natural and human-triggered wind slabs size 1-2 were reported in the White Hills and Big Level areas. Wind slabs were predominantly on east aspects in the alpine. Natural cornice falls were observed in the Tablelands.

Snowpack Summary

5-15 cm of new snow falls amid strong northwest wind over wind-hardened surfaces in the alpine and crust at lower elevations.

Snow from earlier in the week appears to be well-bonded to an underlying rain crust but contains a few storm interfaces 20-40 cm deep that remain reactive in snowpack tests. This may include a layer of graupel which could be slow to bond.

The remainder of the snowpack is composed of alternating layers of crusts and wind-hardened snow, effectively bridging any deeper weak layers.

Weather Summary

Friday night

5-10 cm of new snow. Strong northwest wind. Alpine low -10. Freezing level dropping to sea level.

Saturday

Flurries bringing up to 5 cm of new snow. Moderate northwest wind. Alpine high -10.

Sunday

Around 5 cm of new snow. Moderate westerly wind. Alpine high -10.

Monday

5-15 cm of new snow overnight then clearing to a mix of sun and cloud. Strong northwest wind easing to moderate. Alpine high -3. Freezing level rising to 500 m.

Tuesday

Mostly cloudy. Moderate southwest wind. Alpine high +3. Freezing level rising to 1000m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid freshly wind loaded terrain features.
  • Recent new snow may be hiding windslabs that were easily visible before the snow fell.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow and wind are forming fresh wind slabs in leeward terrain features. They may be especially reactive where they sit over a crust at lower elevations.

In the alpine, older wind slabs may be more stubborn to trigger but given their density and thickness, could potentially have high consequences.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 8th, 2023 11:30AM