Avalanche Forecast

Issued: Feb 8th, 2016 8:09AM

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

pgoddard, Avalanche Canada

South Columbia.

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

Summary

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 http://www.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.

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

Valid until: Feb 9th, 2016 2:00PM