Latopie Lake Avalanche

Location Name: 
Latopie Lake
Region: 
BWRA
Date and time of avalanche (best estimate if unknown): 
Tue, 02/28/2017 - 15:00
Location Map: 


Red Flags: 
Recent avalanche activity
Obvious avalanche path

Observation made by: Avalanche Specialist
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
36degrees
Trigger type: 
Unknown
Crown Height: 
3 ft
Aspect: 
Southeast
Weak Layer: 
Storm Snow
Avalanche Width: 
100ft.
Terrain: 
Above Treeline
Elevation: 
10 650ft.
Bed Surface: 
Old Snow
Avalanche Length: 
900ft.
Number of similar avalanches: 
5-10
Number of people caught: 
0
Number of partial burials: 
0
Number of full burials: 
0
Did the avalanche hit a building, vehicle, or structure?: 
No
More detailed information about the avalanche: 

A fairly large wind slab avalanche (HS-U-R2-D2-I) released along a ridgeline just NE of Latopie Lake.  The debris ran 900' downhill (500' vertical) and covered up recent snowmobile tracks.  It is uknown when this slide released but based on the evidence it ran after the storm on Monday, probably Tuesday afternoon/evening, or even Wednesday morning.  It is also not apparent if this was a natural or human triggered slide, but could've been human triggered due to how recent it ran.

Strong SW winds accompanied a foot of new snow on Sunday/Monday and cross-loaded a 36 degree, SE facing convex rollover where the slide released.  The crown profile showed a recent wind slab sitting on top of softer decomposing new snow about a foot below the surface, where the slide broke.  The crownline was about 5' deep in places where the deepest wind slab pockets were.  Stabilty tests still showed propagation potential between the wind slab and new snow below (ECTP21) meaning lingering instabilty still exists in these wind loaded areas.  There were numerous other recent wind slab avalanches on similar slopes, including several size 2 slides above lower Leavitt Lake Rd and a few near Latopie Lake.

Photo Captions:

1-4:  The Latopie Lake avalanche from several different angles

5:  A size 2 wind slab avalanche above lower Leavitt Lake Rd

6:  A couple of smaller wind slab avalanches near Latopie Lake

Avalanche Photos: 
Snowpit or crown profile photo or graph: 
Avalanche observation video: 

Bridgeport Avalanche Center - Latopie Lake Avalanche - Mar 1, 2017

Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Warming