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Missoula Avalanche

Professional Observation

Basic Information

Observation Details

Observation Date:
March 14, 2022
Submitted:
March 15, 2022
Observer:
WCMAC - Jeff Carty
Zone or Region:
Seeley Swan
Location:
Sunday Mountain

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
None Experienced
On isolated northeast slopes we found limited cracking in the new snow that sits on top of the melt freeze crust. It was confined to the length of our skies and there was no snow movement. No cracking on other aspects.

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
High
Stability Trend: 
Worsening

Bottom Line

We traveled from valley bottom on snowmobiles too 6500' before transferring to skies and making our way to 7600' on the south shoulder of Sunday Mountain in the Swans. We found stable conditions throughout the tour. The new snow seems well bonded to the crust with the exception of isolated areas of cracking on the northeast. North winds have moved snow, cross loading the Swan Ridge and drifts grew as we ascended. However it was well bonded, and we found no signs of instability. The top of the ridge may still hold pockets of reactive wind slab where winds are stronger. Tonight and tomorrow's winds will create reactive wind slab at a variety of elevations.
The crust extends up to about 7000' in the Swan. It is well buried and not apparent under skies until about 6500'. It becomes thicker and less deeply buried below this. Below 6000' the snowpack has been thoroughly saturated and refrozen. Avalanches are unlikely at this elevation, unless we get rain on snow.

Media

Great turns on Sunday Mountain

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Temperature:
30ºF (-1ºC) to 34ºF (1ºC)
Wind:
Light , W

Mild temps today with rising temperature in the afternoon. Winds light and no wind transport was observed. There is plenty of snow available for transport if the wind picks up.

Snowpack Observations

No results of note from test pits, no propagation and good strength.

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