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Professional Observation

Basic Information

Observation Details

Observation Date:
February 9, 2023 - February 10, 2023
Submitted:
February 11, 2023
Observer:
PAC - Kevin Studley
Zone or Region:
Warren Wagon Eastside/Crestline Area
Location:
NW of Box Lake

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
This observation is from an avalanche investigation conducted Friday (02/10) of a snowmobile-triggered avalanche on Thursday (02/09).

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Moderate
Stability Trend: 
Steady

Media

Snowmobile-triggered avalanche NW of Box Lake from Thursday (02/09). SS-AMu-R1-D2-O-7490'-E-1-2' depth
Snowmobile-triggered avalanche NW of Box Lake from Thursday (02/09). SS-AMu-R1-D2-O-7490'-E-1-2' depth
Snowmobile-triggered avalanche NW of Box Lake from Thursday (02/09). SS-AMu-R1-D2-O-7490'-E-1-2' depth
Snowmobile-triggered avalanche NW of Box Lake from Thursday (02/09). SS-AMu-R1-D2-O-7490'-E-1-2' depth
Snowmobile-triggered avalanche NW of Box Lake from Thursday (02/09). SS-AMu-R1-D2-O-7490'-E-1-2' depth
Crown profile from snowmobile-triggered avalanche

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
N/O
Wind:
Light , SW

Clear, sunny, temperatures were in the low 30s around 7500 ft. Drifting and blowing snow was observed near ridgetops from SW winds.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Past 48 hours NW of Box Lake
E 7490 		D2 SS O-Old Snow 20" AM-Snowmobile
u-Unintentional 		Snowmobile-triggered avalanche NW of Box Lake from Thursday (02/09). SS-AMu-R1-D2-O-7490'-E-1-2' depth. Slope steepness averaged 32-35 degrees. The slope angle near the crown was between 38-40 degrees. This avalanche was about 125 feet wide, it ran nearly 400 feet in length, with 200 feet of vertical fall, runout angle of 25 degrees. It failed on a layer of 2-4 mm surface hoar buried in January. None
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