Observation: Hatties Bowl

Observation Date
01/24/2017
Observer Name
Toby Weed

Region:

Location Name or Route
Ridge above Hattie's Bowl
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Speed
Calm
Snow Characteristics
New Snow Depth
2'
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments

Difficult trail breaking, with deep, somewhat inverted new snow

Red Flags
Red Flags
Heavy Snowfall
Collapsing
Poor Snowpack Structure
Avalanche Problem #1
Type
Persistent Slab
Trend
Same
Problem #1 Comments

obvious weak layer of surface hoar and small faceted grains easily visible in snowpit wall.  I was able to initiate full propagation failures on this layer 70 cms below the powdery snow surface.

Avalanche Problem #2
Type
Wind Slab
Trend
Increasing Danger
Problem #2 Comments

Wind slabs from Monday's storm are buried and hidden by several inches of fresh light snow.  

Calm conditions now, but lots of very light powder on the surface will be easily drifted into fresh wind slabs as winds increase.

Snow Profile
Aspect
East
Elevation
6300
Slope Angle
21
Comments

I found a reactive buried weak layer of surface hoar and small faceted grains about 2' under the powdery snow surface.

I went back to Hattie's yesterday (1/25/17) and noticed that much of the lower south side (northeast facing) of the bowl had naturally cracked and collapsed, likely on Monday or Monday night.  The spider web cracks spread across the slope where is had failed.  The only reason it didn't avalanche was the slope angle (about 32 degrees). 

We ski tested a few different areas of the bowl and did not produce any avalanches or observe any red flags other than the existence of the persistent weak layer made up of surface hoar and small faceted crystals. 

Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Snow Profile Coordinates