Wet Slab near Fishes Tooth

Location Name: 
Fishes Tooth- PCT
Region: 
BWRA
Date and time of avalanche (best estimate if unknown): 
Wed, 04/03/2019 - 13:56
Location Map: 


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path
Terrain Trap

Observation made by: Avalanche Specialist
Avalanche Observations
Avalanche Type: 
Wet
Slab
Slope: 
50degrees
Trigger type: 
Natural
Crown Height: 
Less than 1 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
1 500ft.
Terrain: 
Above Treeline
Elevation: 
10 800ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
1 000ft.
Number of similar avalanches: 
5
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: 

The BWRA has had a unique avalanche cycle in the past couple days. Numerous avalanches happened after just following a quick snow shower that deposited 4-8" & was accompanied by moderate SW winds. Adding to the dynamic of this event was the graupel & rime that fell & the timing of intense sunshine & rapid warming after deposition. Prevailing SW winds had transported the new snow to aspects N-E in Wind Slabs. These slabs gained sun & rapid warming soon after falling causing surface instabilities in the upper 15cm, at an interface where there was a change in snow density. At this interface, 15cm down, multiple Wet Slab style avalanches occurred due to the loosening of the new snow grains. Propagating like a Wind Slab but with the debris characteristics of a Loose Wet, this Wet Slab avalanche was rather larger for the shallow depth of snow it entrained. WS-N-R2.5-D2-S I saw 5 similar Wet Slab avalanches along with over 10 Loose Wet slides. The "Repeat Offender" had a good size Loose Wet that only ran 250' in the tract. A confirmed skiier triggered Slab on the South side of Leavitt Cirque took one individual for a long ride. Please submit observations when these events happen, we could use the info!

Avalanche Photos: 
Snowpit or crown profile photo or graph: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

This storm entered warm, got cold quickly, then rapidly warmed soon following. The deposited 4-8" was a mix of broken particles, rime, & graupel; that was transported by SW winds. The emergence of the sun allowed the new snow to melt causing the instabilities.