North Columbia Avalanche Forecast

Mar 19th, 2020 4:00PM

The alpine rating is low, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet.

Warm, sunny weather continues. Use increased caution when slopes and cornices warm up throughout the day. Low hazard doesn't mean no hazard.

Summary

Confidence

Moderate - Uncertainty is due to limitations in the field data.

Weather Forecast

Thursday: Clear, light west wind, alpine temperature -12 C, freezing level valley bottom.

Friday: Clear, light west wind, alpine temperature -5 C, freezing level 1600 m.

Saturday: Increasing cloud, isolated flurries in the afternoon with trace accumulations, light west wind, alpine temperature -4 C, freezing level 1400 m.

Sunday: Mostly cloudy, isolated flurries in the afternoon with trace accumulations, light southwest wind, alpine temperature -7 C, freezing level 1400 m. 

Avalanche Summary

Over the past several days, avalanche activity was reported as natural loose dry or loose wet avalanches size 1-2 running in steep, sun-exposed terrain in the alpine. One large (size 2) slab avalanche released naturally as a result of strong solar radiation on a south aspect at 2500 m. There were also several large cornice failures on northerly aspects (up to size 2.5).

The number of data sources for the region is diminishing as professional operations close. If you're spending time in the mountains, consider sharing your observations via the Mountain Information Network. Heightened diligence and conservative risk management is recommended at this time.

Snowpack Summary

On Wednesday, temperatures reached 0 C up to 2000 m with strong solar radiation. You can expect to find either moist surface snow or crust on sun-exposed slopes. 

Snow from last week may sit on a surface hoar layer and a crust on steep solar aspects. Moderate to strong northeast and east wind redistributed snow and formed wind slabs that may remain possible to trigger in isolated areas.  

A widespread weak layer of surface hoar buried at the end of February is 60-100 cm deep. Sheltered north, northeast, and east facing slopes near treeline are the most likely locations to find this layer. Avalanche activity on this layer was last reported on March 8th. There is a low likelihood of triggering an avalanche on this layer, but the consequences of doing so would be high. Read more about surface hoar on our forecaster blog.

Terrain and Travel

  • Back off slopes as the surface becomes moist or wet with rising temperatures.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
  • Make observations and assess conditions continually as you travel.

Problems

Loose Wet

An icon showing Loose Wet

Likelihood

Unlikely-Possible

Expected Size

1 - 1.5

Small loose dry or wet avalanches are possible in steep terrain facing the sun during the heat of the day. Cornices may also warm and weaken and could act as triggers for large slab avalanches.

Aspects:

South East, South, South West, West.

Elevations:

All elevations.

Valid until: Mar 20th, 2020 5:00PM