Avalanche Forecast

Issued: Apr 17th, 2023 4:00PM

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

Avalanche Canada jsmith, Avalanche Canada

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Lingering wind slabs may remain reactive to human triggers on lee aspects in the alpine.

Avoid steep, rocky, and wind affected areas where triggering slabs are more likely.

Summary

Confidence

Low

Avalanche Summary

No new avalanches were reported on Sunday. However, observations are very limited during this time of year.

A naturally triggered size 2 wind slab was reported on a north aspect in the alpine in the Ashman zone on Thursday. See MIN.

Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.

Snowpack Summary

20-40 cm of snow last week was redistributed into wind slabs on northerly aspects by south winds. The snow sits over wind-affected surfaces or a crust on south-facing slopes.

A weak layer buried in late March is down 30-40cm and exists as surface hoar and facets on north facing slopes and a crust elsewhere. It has produced recent test results and may be reactive to human triggers in isolated locations where the layer is well-preserved and has a cohesive overlying slab. See MIN.

The middle of the snowpack is strong and contains numerous hard crusts. Near the ground, weak faceted crystals exist. There hasn't been avalanche activity on this layer recently, but it remains on our radar as it may become active with abrupt changes to the snowpack, such as rapid loading (heavy snowfall or rain) or prolonged warming.

Weather Summary

Monday Night

Partly cloudy / 10 km/h east ridgetop wind / Temperature at treeline around -6C / Freezing level valley bottom

Tuesday

Mix of sun and cloud with isolated flurries; 0-10 cm / 20 km/h east ridgetop wind / Temperature at treeline around -4 C / Freezing level 1300 m

Wednesday

Mix of sun and cloud / 35 km/h east ridgetop wind / Temperature at treeline around -2 C / Freezing level 1500 m

Thursday

Mix of sun and cloud with isolated flurries; 0-3 cm / 20 km/h southeast ridgetop wind / Temperature at treeline around -2 C / Freezing level 1500 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Cornice failure may trigger large avalanches.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Wind Slabs

An icon showing Wind Slabs

Lingering wind slabs may remain reactive to human triggers on lee aspects in the alpine.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Strong solar radiation may trigger wet loose avalanches on steep, sunny slopes.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Apr 18th, 2023 4:00PM