Avalanche Forecast

Issued: Jan 25th, 2015 9:22AM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs, Deep Persistent Slabs and Loose Wet.

jlammers, Avalanche Canada

Northwest Inland.

Continued wind, snow and warming has added more stress to buried weak crystals. Conservative terrain selection remains critical.

Summary

Confidence

Poor - Due to the number and quality of field observations

Weather Forecast

The active weather pattern will continue as a fairly strong and moist southwest flow remains aimed at the region. Monday: Light to moderate snowfall, intensifying throughout the day / Light southwest winds intensifying to strong values throughout the day / Freezing level at 1000m Monday night and Tuesday: Up to 20cm of snow / Strong southwest winds / Freezing level at 1000m Wednesday: Light to moderate snowfall / Strong southwest winds / Freezing level at 1000m

Avalanche Summary

Avalanche observations have been very limited in recent days. This may speak more to a lack of observations rather than actual conditions. Periods of heavy snow or rain, strong ridge winds, and warming will probably tip off a natural avalanche cycle in parts of the region. We could see wet activity at lower elevations with storm/wind slabs where snow accumulates. There is also potential for deep persistent weaknesses to be overloaded producing isolated very large and deep slides.

Snowpack Summary

Continued snowfall has contributed to ongoing storm slab development. Warm temperatures have promoted rapid slab settlement, while rain has created wet loose surface snow at lower elevations. Southwest winds continue to build slabs on leeward slopes with cornices overhead in exposed treeline and alpine terrain. A crust/ surface hoar combo buried in the middle of January may be around 50-80 cm deep now. In the mid-pack, a crust weakness buried in mid-December seems to be unreactive for the time being. Near the base of the snowpack is the crust-facet combination buried in November that could remain problematic, especially in shallower snowpack areas with heavy loading and warming.

Problems

Storm Slabs

Continued snowfall, warming and extreme winds have added to the destructive potential of a developing storm slab. Storm loading or an avalanche in motion may also trigger more destructive persistent weaknesses deeper in the snowpack.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be alert to conditions that change with elevation.>Choose conservative lines and watch for clues of instability.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Heavy loading from wind, snow and/or rain could trigger deep persistent weaknesses and produce isolated very large avalanches.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 6

Loose Wet

The snowpack is saturated at elevations where rain has fallen. Pushy loose wet avalanches are a concern in steep terrain.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Even small avalanches may run a long ways under the current conditions.>Be cautious of wet sluffing in steep terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 26th, 2015 2:00PM