Avalanche Forecast

Issued: Jan 14th, 2022 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Avoid all avalanche terrain during periods of heavy loading from snow, wind, or rain. 

The track of this storm is uncertain, and the south end of the region is forecasted to receive more intense snow and rain. 

The hazard ratings below reflect these higher precipitation areas. 

Summary

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system. Uncertainty is due to difficult to forecast freezing levels.

Weather Forecast

The heaviest precipitation for this storm didn't arrive as forecasted on Friday, and has been pushed back to Friday night. Expect snowfall amounts to vary greatly across the region, with highest amounts falling in the area around Kitimat, and possibly as far north as Terrace.

Friday Night: Cloudy. 15-20 cm of snow expected. Possibly 30 cm or more in the south of the region. Strong to extreme southwest wind. Freezing level around 1000 m. 

Saturday: Cloudy. 5-15 cm of snow expected. Extreme southwest wind, trending to strong through the day. Freezing level around 800 m. 

Sunday: Cloudy. 2-10 cm of snow expected overnight, and another 10-20 through the day. Strong southwest wind, trending to extreme at higher elevations, possibly above 100 km/h. Freezing level around 1000 m. 

Monday: Partly cloudy. 2-10 cm of snow expected overnight, and a possible trace through the day. Moderate west wind, trending to strong northwest at higher elevations. Freezing level falling to around 500 m.

Avalanche Summary

On Friday, a few professional operations across the region reported large natural and explosive triggered loose wet avalanches at and below treeline as temperatures increased.

On Thursday, east of Port Essington, a professional operation reported several loose wet and wet slab avalanches up to size 2.5, below 1000 m on southeast aspects.

Also, a professional operation north of Bear Pass reported two remotely triggered avalanches in recent storm snow, size 1.5-2. These were on north through southeast aspects around treeline. They were reported to have failed on a weak layer of facets that was buried on January 8.

Remember that a lack of observed avalanches does not necessarily mean that there is a lack of avalanche activity. If you are getting out in the backcountry, and have conditions information, or even just good vibes and good photos to share, consider making a post on the Mountain Information Network (MIN). 

Snowpack Summary

By the end of the day on Saturday, expect storm totals to reach 25-45 cm. Strong to extreme southwest winds are potentially increasing the reactivity of storm slabs in lee features. 

Terrain below 1000 m that sees moderate to heavy rainfall could become more avalanche prone due to loose-wet avalanches or an upside down upper snowpack. 

50-100 cm below the snow surface, Faceting from the prolonged cold temperatures may increase the chance of a storm slab in motion stepping down to the previous storm interface.  

The early December rain crust is up to 10 cm thick, down 100-200 cm in the snowpack, and exists to an average of 1400 m in elevation. While this layer had generally gone dormant in the region through the cold period, it still has the possibility of waking up and will be tested this week with the forecast warming event and ongoing snow accumulation. 

Extra caution is necessary while the snowpack undergoes substantial warming after a prolonged period of cold conditions. 

Terrain and Travel

  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Dial back your terrain choices if you are seeing more than 30 cm of new snow.
  • Extra caution for areas experiencing rapidly warming temperatures for the first time.
  • Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.

Problems

Storm Slabs

An icon showing Storm Slabs

Snowfall continues through the day, we are expecting a storm total of 25-45 cm by the end of the day on friday. Strong southwest wind is potentially increasing the reactivity of storm slabs in lee features. 

Freezing levels are variable over the region, and could depend on the intensity of the storm, so be ready for the snow/rain conditions to vary as you change elevations, and as the day progresses.

50-100 cm below the snow surface, Faceting from the prolonged cold temperatures may increase the chance of a storm slab in motion stepping down to the previous storm interface.  

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

Deeply buried weak layers in the snowpack will get tested this week with substantial warming and ongoing snow loading. While these layers have been dormant through the extended cold period, they have the potential to wake up this week, and smaller storm slab avalanches have the potential to step down to a deeper layer. Use extra caution and give the snowpack time to adjust to the warm conditions. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Loose Wet

An icon showing Loose Wet

Some low elevation areas may see above zero temperatures and moderate to heavy rainfall.

This can rapidly weaken the snowpack, so stick to mellow slopes if you see large chunks of snow falling off of trees, pinwheeling or snowballing on slopes, or recent avalanches.  

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 15th, 2022 4:00PM