Avalanche Forecast

Issued: Apr 19th, 2023 4:00PM

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

Avalanche Canada swerner, Avalanche Canada

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Fresh wind slabs may be reactive to human triggers on leeward slopes in the alpine.

Short bursts of the warm April sun can weaken the upper snowpack quickly. Avoid solar slopes if the sun is shining.

Summary

Confidence

Low

Avalanche Summary

No new reports on Wednesday.

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

Recent southerly winds have redistributed dry snow forming isolated wind slabs on leeward slopes and behind terrain features. The snow sits over wind-affected surfaces or a crust on south-facing slopes.

A weak layer buried in late March is down 30-50 cm and exists as surface hoar and facets on north-facing slopes and a crust elsewhere. Test results show that this layer may be reactive to human triggers in isolated locations on north-facing slopes where the layer is well-preserved and have a cohesive overlying slab.

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 and may become active when we experience change, such as rapid loading (heavy snowfall or rain) or prolonged warming.

Weather Summary

Wednesday Night

Trace of new snow. Ridgetop winds 40-50 km/h from the southeast. Temperature at treeline around -5 C and freezing level valley bottom.

Thursday

Mostly cloudy. Ridgetop wind 30-50 km/h from the southeast. Temperature at treeline around -4 C freezing level 1300 m.

Friday

Mix of sun and cloud. Ridgetop wind 15-20 km/h from the southwest. Temperature at treeline around -4C with freezing level 1100 m.

Saturday

Cloudy. Ridgteop wind 30-50 Km/h from the southwest. Temperature at treeline around -4 C with freezing level near 1300 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Wind slabs may be poorly bonded to the underlying crust.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Be alert to conditions that change with elevation and sun exposure.

Problems

Wind Slabs

An icon showing Wind Slabs

Fresh wind slabs may be reactive to human triggers on lee aspects in the alpine.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Even short periods of 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

Expected Size

1 - 1.5

Valid until: Apr 20th, 2023 4:00PM

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