Natural persistent slabs above Skiumah Lake
| 
      Location Name:  Forecaster Observation - Skiumah Lake, Flathead Range Observation date:  Thursday, December 20, 2018 - 16:15  | 
   
        Is this an Avalanche Observation:  Yes  | 
 
|---|
	Observation made by: Forecaster
Location
Tabs
Avalanche Details: 
Date and Time of Avalanche: 
Wednesday, December 19, 2018 - 02:00
Avalanche Type: 
Hard Slab
Failure Plane/Weak Layer: 
Old snow
Trigger: 
natural
Aspect: 
North
Starting Elevation: 
7000
Destructive Size: 
D2.5
Relative Size: 
R2 Small
Crown Height: 
4 ft
Avalanche Length (Vertical Run): 
500ft.
Avalanche Width (Average width): 
250ft.
Avalanche Location: 
Date and Time of Avalanche: 
Wednesday, December 19, 2018 - 02:45
Avalanche Type: 
Soft Slab
Failure Plane/Weak Layer: 
Unknown
More information or comments about the avalanche: 
Viewed from debris pile; crown appeared to be a storm / wind slab but ran a far distance and entrained wet snow lower down.
Trigger: 
natural
Aspect: 
North
Starting Elevation: 
6700
Destructive Size: 
D2.5
Relative Size: 
R3 Medium
Crown Height: 
2 ft
Avalanche Length (Vertical Run): 
2100ft.
Avalanche Width (Average width): 
300ft.
Avalanche Location: 
Date and Time of Avalanche: 
Wednesday, December 19, 2018 - 02:45
Avalanche Type: 
Soft Slab
Failure Plane/Weak Layer: 
New/old snow interface
More information or comments about the avalanche: 
Trigger: 
natural
Aspect: 
North
Starting Elevation: 
above-treeline
Destructive Size: 
D1.5
Relative Size: 
R1 Very Small
Crown Height: 
1 ft
Avalanche Location: 










2 persistent slab avalanches broke just above the 11/3 crust. One may have been triggered by a step down wind slab