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Avalanche Forecast

Feb 8th, 2016–Feb 9th, 2016
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: South Columbia.

Skyrocketing temperatures are expected to weaken surface snow layers, make cornices extra fragile and possibly wake up deeply buried weak layers.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

A strong ridge of high pressure is expected to bring sunny skies above valley cloud. Valley cloud tops should be around 1500 m. A warm southerly flow causes alpine temperatures to rise well above 0, with peak warming and sunshine on Tuesday. Some light precipitation may arrive on Thursday with the passage of a warm front.For more details check out https://avalanche.ca/weather.

Avalanche Summary

A cycle of size 1-3 avalanches was triggered naturally and by skiers and explosives on Saturday in response to new snow and very strong SW winds. A few further storm/wind slabs were reported on Sunday. During this widespread cycle, only a couple of persistent slabs were reported. While the likelihood of triggering a persistent slab has gone down, the consequences remain high. Forecast warming may make the persistent slab easier to trigger again. Cornice fall or a surface avalanche could also trigger a persistent slab.

Snowpack Summary

Warm temperatures and sunshine are expected to weaken and moisten surface snow layers. Strong to extreme SW winds on Saturday created wind slabs and cornices in many areas. In sheltered areas, 15-40 cm recent storm snow is settling, and in some places may still be reactive as a soft slab. A rain crust sits below this in parts of the Monashees. In the far south, a layer of surface hoar is buried about 50-80 cm down. Professionals are still monitoring the early January persistent weak layer, down 80-120 cm. The persistent slab above this has become an infrequent performer. However, in specific locations, it still produces hard, sudden results in snowpack tests, and forecast warming could wake it up again.

Avalanche Problems

Loose Wet

Strong sunshine and warm temperatures are expected to weaken surface snow layers and cause loose wet avalanches or wet slabs.
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of what is above you at all times.>Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >

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

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

Wind Slabs

Very strong winds have created wind slabs and fragile cornices on a variety of slopes. These may be extra sensitive with warm temperatures and sunshine.
Use ridges or ribs to avoid wind loaded slopes.>Avoid steep slopes below cornices.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

A deeply buried weak layer can still be triggered in some places, creating very large avalanches. Forecast warming may increase the sensitivity of this problem.
Minimize exposure to sun exposed slopes when the solar radiation is strong.>Be cautious of open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 3 - 5