Archived

Avalanche Forecast

Feb 10th, 2017–Feb 11th, 2017

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Cariboos.

Conditions are primed for people triggering avalanches, and wind-loading is expected to result in continued natural avalanche activity. Stick to simple terrain until the fresh snow has a chance to settle and strengthen.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

SATURDAY: Cloudy with flurries bringing another 5-10 cm of fresh snow, moderate to strong southwesterly winds, with freezing levels around 1200 m.SUNDAY: A mix of sun and cloud with isolated light flurries possible, strong southwesterly winds and freezing levels as high as 1600 m.MONDAY: A mix of sun and cloud with isolated light flurries possible, strong southwesterly winds and freezing levels as high as 2000 m.

Avalanche Summary

No new avalanches were reported on Thursday, but initial reports from Friday include several natural storm slab avalanches up to Size 2.5. Expect natural avalanche activity to continue with sustained loading from snow and wind, and fresh storm slabs will remain sensitive to light triggers.

Snowpack Summary

With up to 50 cm of fresh snow on Friday, total snowfall over the past week is around 70 cm with warm temperatures and wind forming very touchy slabs. Weaknesses likely exist within this recent storm, which is also bonding poorly to the previous snow surface from early February that includes old hard wind slabs and crusts as well as faceted snow and surface hoar on sheltered open slopes. The persistent weakness buried mid-January is now down around a metre and consists of buried surface hoar in sheltered areas, and/or widespread faceted old snow. It has generally stabilized but may remain reactive in isolated areas where buried surface hoar is preserved. Another surface hoar/facet weakness buried mid-December can now be found over a metre in shallow snowpack areas. While reactivity at this layer has declined, professionals in the region are still treating it with a great deal of caution.

Avalanche Problems

Storm Slabs

Continued wind-loading will likely result in sustained natural avalanche activity. Fresh storm slabs are highly sensitive to light triggers, and especially deep and touchy on wind-loaded slopes.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

Persistent Slabs

A persistent weakness buried in mid-December was responsible for several large human-triggered avalanches in late January. Another weakness buried in mid-January produced a remotely triggered avalanche within the last week.

Avoid shallow snowpack areas where triggering is more likely.Use conservative route selection, choose moderate angled and supported terrain with low consequence.Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4