Take a short ride up a long canyon

Location Name: Swan River State Forest Observation date: Tuesday, January 11, 2022 - 12:00	Is this an Avalanche Observation: Yes

Observation made by: Public

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Quick Observation

Checking to see how the roads held up after the most recent storm:

Plenty of debris from the 1/7 rain and resulting cycle
Slides were confined to low and mid elevations and small in destructive size
Found some stiff and stubborn old windslab at mid-elevations, in some cases this cracked around our machines
It snowed lightly on our drive but stopped by 1100
Winds picked up enough to start blowing snow

Snowpack, Avalanche, Weather Images:

Travel Details

Region:

Swan Range - South (south of Swan Lake)

Activity:

Snowmobiling

Snowpack Details

Snowpack and Weather Details:

Terrain

Elevation of observation:

3500-5000 ft

5000-6500 ft

Above 6500 ft

Aspect(s) of observation:

Red Flags:

Blowing snow

New Snow in the past 24 hours:

1.00in.

More comments about the snowpack and weather:

Snowfall stopped at 1100. Wind picked up around 1300. Felt like the wind was coming from the North, maybe due to terrain. Found 15-20cm windslab (1F) on NE and S aspects.

Blowing Snow:

Moderate

Wind Speed:

Moderate (Small trees sway)

Air temperature:

Below Freezing

Sky Cover:

Obscured by fog, etc (X)

Highest Precipitation Rate:

Very Light Snowfall (S-1)

Avalanche Details

Avalanche Details:

Date and Time of Avalanche:

Friday, January 7, 2022 - 12:00

Number of avalanches:

Avalanche Type:

Wet Loose

Failure Plane/Weak Layer:

Within storm snow

More information or comments about the avalanche:

Could not see start zones.

Trigger

Trigger:

natural

Terrain

Aspect:

South

Starting Elevation:

near-treeline

Size

Destructive Size:

D2 Could bury, injure, or kill a person.

Date and Time of Avalanche:

Friday, January 7, 2022 - 12:00

Number of avalanches:

Avalanche Type:

Wet Slab

Failure Plane/Weak Layer:

Within storm snow

More information or comments about the avalanche:

Long cut slope failed above road.

Trigger

Trigger:

natural

Terrain

Start Zone Slope Angle:

Aspect:

South

Starting Elevation:

below-treeline

Size

Destructive Size:

D1.5

Relative Size:

R4 Large

Crown Height:

Less than 1 ft

Avalanche Length (Vertical Run):

50ft.

Avalanche Width (Average width):

800ft.

Date and Time of Avalanche:

Friday, January 7, 2022 - 12:00

Number of avalanches:

Failure Plane/Weak Layer:

Within storm snow

More information or comments about the avalanche:

Several slab failed on fill slope below road.

Trigger

Trigger:

natural

Terrain

Start Zone Slope Angle:

Aspect:

South

Starting Elevation:

below-treeline

Size

Destructive Size:

D1 Relatively harmless to people.

Relative Size:

R1 Very Small

Crown Height:

Less than 1 ft

Avalanche Length (Vertical Run):

50ft.

Avalanche Width (Average width):

50ft.

Date and Time of Avalanche:

Friday, January 7, 2022 - 12:00

Number of avalanches:

Avalanche Type:

Wet Loose

Failure Plane/Weak Layer:

Within storm snow

More information or comments about the avalanche:

Roughly a dozen small chunky debris piles in the roads.

Trigger

Trigger:

natural

Terrain

Aspect:

South

Starting Elevation:

below-treeline

Size

Destructive Size:

D1 Relatively harmless to people.

Relative Size:

R1 Very Small

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