More debris from last week's warming

Location Name: 
Flathead Range
Observation date: 
Tuesday, April 14, 2020 - 16:15
Is this an Avalanche Observation: 
Yes
Observation made by: Public

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Quick Observation

We went for a gentle tour to enjoy low-angle corn snow and observe avalanche activity related to last week's warming.

  • Balmy temperatures April 8-10 put the hurt on southeasterly slopes resulting in 1 D3, 1 D2.5, 3 D2, and a dozen D1.5 wet loose slides. One of these appears to have initiated a wet slab avalanche on an east aspect at approximately 5000'. 
  • A slab avalanche was observed on an east aspect at 7200'. It appears to have been started by a point release sluff.
  • Northerly slopes fared slightly better with 10 D1-1.5 slides and numerous rollerballs.
  • Several days of cold temperatures left a supportable snow surface at low and mid-elevations. Today's corn window appeared to be relatively long with just the top few inches softened by 2:00 p.m at low and mid-elevations. 
Snowpack, Avalanche, Weather Images: 
Travel Details
Region: 
Flathead Range - Middle Fork Corridor
Activity: 
Skiing
Snowpack Details
Snowpack and Weather Details: 
Hide Terrain
Elevation of observation: 
3500-5000 ft
5000-6500 ft
Aspect(s) of observation: 
E
SE
S
Persistent Weak Layers: 
Not observed
New Snow in the past 24 hours: 
0.00in.
Wind Speed: 
Light (Twigs in motion)
Wind Direction: 
West
Air temperature: 
Above Freezing
Snow line: 
3000'
Sky Cover: 
Mostly Clear (FEW)
Avalanche Details
Avalanche Details: 
Date and Time of Avalanche: 
Thursday, April 9, 2020 - 12:15
Number of avalanches: 
1
Avalanche Type: 
Wet Loose
Failure Plane/Weak Layer: 
Within storm snow
More information or comments about the avalanche: 

Several large wet loose slides merged in a gulley depositing a D3 debris pile.

Hide Trigger
Trigger: 
natural
Hide Terrain
Start Zone Slope Angle: 
35
Aspect: 
Southeast
Starting Elevation: 
near-treeline
Hide Size
Destructive Size: 
D3 - Could destroy a car, a wood house, or snap trees
Relative Size: 
R3 Medium
Avalanche Length (Vertical Run): 
1600ft.
Avalanche Width (Average width): 
400ft.
Avalanche Location: 
Date and Time of Avalanche: 
Thursday, April 9, 2020 - 12:15
Number of avalanches: 
1
Avalanche Type: 
Wet Loose
Failure Plane/Weak Layer: 
Within storm snow
More information or comments about the avalanche: 
Hide Trigger
Trigger: 
natural
Hide Terrain
Start Zone Slope Angle: 
35
Aspect: 
Southeast
Starting Elevation: 
near-treeline
Hide Size
Destructive Size: 
D2 Could bury, injure, or kill a person.
Relative Size: 
R2 Small
Avalanche Length (Vertical Run): 
1500ft.
Avalanche Width (Average width): 
100ft.
Avalanche Location: 
Date and Time of Avalanche: 
Thursday, April 9, 2020 - 12:15
Number of avalanches: 
3
Avalanche Type: 
Wet Loose
Failure Plane/Weak Layer: 
Within storm snow
More information or comments about the avalanche: 
Hide Trigger
Trigger: 
natural
Hide Terrain
Start Zone Slope Angle: 
35
Aspect: 
Southeast
Starting Elevation: 
near-treeline
Hide Size
Destructive Size: 
D2 Could bury, injure, or kill a person.
Relative Size: 
R2 Small
Avalanche Length (Vertical Run): 
1000ft.
Avalanche Width (Average width): 
75ft.
Avalanche Location: 
Date and Time of Avalanche: 
Thursday, April 9, 2020 - 12:15
Avalanche Type: 
Wet Loose
Failure Plane/Weak Layer: 
Within storm snow
More information or comments about the avalanche: 
Hide Trigger
Trigger: 
natural
Hide Terrain
Start Zone Slope Angle: 
35
Aspect: 
Southeast
Starting Elevation: 
near-treeline
Hide Size
Destructive Size: 
D1.5
Relative Size: 
R2 Small
Avalanche Length (Vertical Run): 
400ft.
Avalanche Width (Average width): 
50ft.
Avalanche Location: 
Date and Time of Avalanche: 
Thursday, April 9, 2020 - 12:15
Number of avalanches: 
1
Avalanche Type: 
Soft Slab
Failure Plane/Weak Layer: 
Other - explain below
More information or comments about the avalanche: 

This may be a persistent slab that failed on the 3/24 weak layer.

Hide Trigger
Trigger: 
natural
Hide Terrain
Start Zone Slope Angle: 
40
Aspect: 
East
Starting Elevation: 
7200'
Hide Size
Destructive Size: 
D2 Could bury, injure, or kill a person.
Relative Size: 
R2 Small
Crown Height: 
2 ft
Avalanche Length (Vertical Run): 
1200ft.
Avalanche Width (Average width): 
100ft.
Avalanche Location: 
Date and Time of Avalanche: 
Thursday, April 9, 2020 - 12:30
Number of avalanches: 
10
Avalanche Type: 
Loose Dry/ Sluff
Failure Plane/Weak Layer: 
Within storm snow
More information or comments about the avalanche: 

On NE-NW aspects.

Hide Trigger
Trigger: 
natural
Hide Terrain
Start Zone Slope Angle: 
35
Aspect: 
Northwest
Starting Elevation: 
near-treeline
Hide Size
Destructive Size: 
D1.5
Relative Size: 
R1 Very Small
Avalanche Length (Vertical Run): 
200ft.
Avalanche Width (Average width): 
30ft.
Avalanche Location: