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Avalanche Forecast

Apr 18th, 2022–Apr 19th, 2022
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
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

Regions: North Columbia.

Be mindful of reactive slabs forming with new snow, the deepest deposits will be in areas loaded by wind. Bump the hazard to Considerable if you find more than 20 cm fresh snow in your riding area.

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

MONDAY NIGHT: Cloudy with flurries, 5-15 cm. Treeline low -6 C. Increasing southeast-southwest wind, 15-30 km/h.

TUESDAY: Wet flurries and snow, another 5-10 cm through the day with rain below 1400 m. Treeline temperatures rising to -2 C. Wind 15-30 km/h from the west. 

WEDNESDAY: Partially cloudy. Treeline temperatures rising to +1 C, freezing level reaching 1700 m. Light wind from the south. 

THURSDAY: Mix of sun and clouds. Treeline temperatures rising to +2 C. Light winds from the southeast.

Avalanche Summary

Avalanche activity the last week has primarily been large cornice failures on north and east-facing slopes. For the most part, these have not triggered avalanches on the slopes below.

Snowpack Summary

At treeline and higher, fresh snow will cover old wind slab and wind press, and up to 20 cm of old snow. This sits on a melt-freeze crust all aspects to 2000 m and mountain tops on solar aspects. Another prominent crust layer is found 30-70 cm deep. 

Cornices are very large and exposure to slopes beneath them should be minimized, especially if the weather is sunny, warm, or windy. The snowpack deteriorates rapidly at lower elevations.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Closely monitor how the new snow is bonding to the crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Avalanche Problems

Wind Slabs

Upwards of 15 cm flurries is forecast to accumulate by the end of Tuesday, with localized areas getting up to 25 cm. New snow is not expected to bond well with the old surfaces, particularly on the old crust. Expect slab reactivity to increase through the day, especially in wind-loaded terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

Cornices may be weak and reactive to human triggers. Give them a wide berth when travelling on ridges. They are a significant hazard alone and may produce large slab avalanches as they fall onto the slope below. Cornice falls are more likely when the weather is sunny, warm, or windy.

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

Elevations: Alpine.

Likelihood: Unlikely

Expected Size: 1.5 - 3