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Avalanche Forecast

Jan 24th, 2016–Jan 25th, 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
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
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.

Wind and storm slabs are a big concern right now. Use caution around tree line and above.A Special Public Avalanche Warning is in effect for this forecast region.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

The  southern interior will be under the influence of a weak high pressure system for the forecast period.  Partly cloudy skies with some sunny periods and freezing levels at valley bottom overnight, then rising to around 1000 metres during the day.    In advance of he next Pacific frontal system, freezing levels on Tuesday may rise to 2000 metres.

Avalanche Summary

Numerous slab avalanches up to size 2.5 have been reported in the past 2 days. Many were naturals as a result of recent storm loading. A large number were skier controlled. Many of these failed around treeline and below, on buried surface hoar, between 20-40 cm deep. Many of these were triggered remotely, highlighting the volatility of the persistent slab. An increasing number of wind slabs have also been failing at alpine/ treeline elevations, and also running on surface hoar. It is likely that a natural avalanche cycle occurred on Friday and perhaps Saturday after the warm, windy storm.

Snowpack Summary

Recent snowfalls and south west winds have created new storm slabs throughout the region and wind slabs on lee features. This has added additional load and stress to an already touchy persistent slab. This 40-90 cm thick persistent slab overlies a variety of surfaces including large surface hoar, sun crusts, rime crusts and facets. The slab is ripe for human and natural triggers and is especially touchy at and below treeline. The mid and lower snowpack are generally well settled and strong.

Avalanche Problems

Storm Slabs

Wind and storm slabs are the chief concern these days,  above and below tree line, and on all lee aspects in the alpine.
Avoid lee and cross-loaded terrain near ridge crests.>Choose well supported terrain without convexities.>Use ridges or ribs to avoid wind loaded slopes.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3

Persistent Slabs

A small wind or storm slab avalanche might provide enough mass to trigger this deeper instability.
Avoid steep open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Use conservative route selection and be aware of the possibility of remote triggering.>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 5