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Avalanche Forecast

Apr 9th, 2021–Apr 10th, 2021
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
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: North Rockies.

Fresh snow and shifting wind directions may form reactive wind slabs on many aspects. Pay close attention to the patterns of wind loading where you are riding and back off if you encounter whumpfing, cracking or hollow sounds.

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Friday night - Flurries, 5-15 cm / strong southwest wind, switching to moderate northwest / alpine low temperature near -11 

Saturday - Mainly cloudy with a few flurries / light to moderate northwest wind / alpine high temperature near -10 

Sunday - A mix of sun and cloud with isolated flurries / light to moderate northwest wind / alpine high temperature near -9 / freezing level 1000 m 

Monday - Mainly sunny / light northeast wind / alpine high temperature near -7 / freezing level 1500 m

Avalanche Summary

There was a rider triggered size 1 storm slab avalanche reported on an east aspect at treeline on Wednesday, check out the MIN report here. There were no new avalanches reported on Thursday.

Looking forward, fresh snow and wind may create reactive slabs on multiple aspects due to a shift in wind direction. Human triggered avalanches will be the most likely in areas that have seen the highest recent snowfall amounts.

Snowpack Summary

Anywhere from 10-30 cm of new snow is expected by Saturday morning. Strong southwest winds overnight, switching to moderate northwest on Saturday could form wind slabs on many aspects.

The new snow likely sits on a crust everywhere except north aspects above 1700 m, where it sits on previously dry snow.

Recent weather patterns have helped deeper weak layers gain strength, including the mid-February facet layer that is now roughly 150 cm deep. However, it may still be possible to trigger avalanches on basal layers in shallow rocky terrain along the eastern slopes of the Rockies.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Avalanche Problems

Wind Slabs

Fresh wind slabs may form on many aspects with new snow and shifting wind directions on Friday night and Saturday. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2