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Avalanche Forecast

Apr 20th, 2023–Apr 21st, 2023
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Howson, Kitimat, Seven Sisters.

Triggering large persistent slab avalanches on weak facets in the alpine is currently the primary concern.

Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Confidence

Low

Avalanche Summary

No avalanches were reported on Wednesday. However, observations in this region are currently very limited.

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

10-20 cm of recent snow and strong southeast wind formed wind slabs that may remain reactive to human triggers in isolated locations in the alpine. A crust exists up to ridgetop on south-facing slopes and on all aspects up to approximately 1300 m.

A weak layer buried in late March is down 40-60 cm and exists as surface hoar and facets on north-facing slopes and a crust elsewhere.

At treeline elevations, a melt-freeze crust exists on all aspects.

The mid and lower snowpack is considered generally strong and well-bonded.

Weather Summary

Thursday Night

Partly cloudy / 10 km/h northwest ridgetop wind / Temperature at treeline around -4 C / Freezing level 800 m

Friday

Mix of sun and cloud / 20 km/h southwest ridgetop wind / Temperature at treeline around -2 C / Freezing level 1400 m

Saturday

Snow; 5-15 cm / 60 km/h south ridgetop wind / Temperature at treeline around -3 C / Freezing level 1300 m

Sunday

Cloudy with flurries; 5-10 cm / 30 km/h south ridgetop wind / Temperature at treeline around -4 C / Freezing level 1200 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Wind slabs may be poorly bonded to the underlying crust.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Avalanche Problems

Persistent Slabs

A weak layer buried in late March is down 40-60 cm and exists as surface hoar and facets on north-facing slopes and a crust elsewhere.

We currently have very limited snowpack observations from this region to aid in determining the likelihood of triggering avalanches on the layer.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1.5 - 3

Wind Slabs

Lingering wind slabs may be reactive to rider triggering on leeward slopes in the alpine.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2