Mammoth Lakes Basin - TJ Bowl- Snowpack and test results

TJ Bowl
Submission Info
Tuesday, January 16, 2018 - 3:15pm
Red Flags: 
37° 34' 36.642" N, 119° 0' 27.7344" W
Snowpit Observations
More detailed information about the snowpack: 

Toured from Tamarack up Make Mary Ridge, to TJ Bowl and the ridge crest and back, searching for signs of instability in the form of windslabs that were deposited last Wednesday as winds increased substantially after the most recent storm last Tuesday, and propagation of fractures in the old snow in the persistent loose sugary faceted snow buried deeper in the snowpack.  Summary:  Shallow windslabs require moderate to hard force to fail, but are still failing cleanly.  Multpile pits resulted in fracture failures, but no tests showed propensity for fractures to propagate.  Details below:     

Doing hand pits in the same locations (but next to) as I did last Friday at tree line and above, resulted in clean planar fractures under 1-5" of firm windslab (as they did last Friday), but consistently required moderate to hard force, as opposed to on Friday when they released with light pressure.

Pits dug at 9,260' N facing, and 9,920' in sheltered little basin, and another on steep exposed ENE facing slope at 10,950'.  See attached profile for lower elevation pit dug just below ridgetop of Lake Mary ridge (multpile consistent failures, but no propagation).  

For 9,920' elevation pit:  CT22- Q1 @ 24 cm down in subtle layer in last weeks storm snow.  CT 30-Q1@ 44cm down in the top (but not at interface) of old faceted snow under last week's new snow.  

-0-40cm: New snow from last week

-40-41cm: Thin melt freeze crust (subtle)

-41-60cm: Old faceted snow, 4finger hardness

-60-65cm: Decomposing melt-freeze crust

-65-112cm: 1finger rounding facets to ground


Above tree line just below rocks mid-way up slope above TJ bowl, NNE facing, 40deg slope, 10,950':  Total snow depth ranged from 190cm to 240cm within a few foot area.  Did not dig to ground.  Probing, seemed that some of this snow was old snow from last year possibly (firm, but not as firm as I expected in lower half).  Surface firm windslab (1-2") failed easily either upon isolation or with light force.  CT25-Q1 @35cm down in softer 4finger snow (not facets) below 1finger denser snow.  Air temp=-2deg C at 4pm.  ECTX.  

*Melt freeze crusts were found even on North facing slopes (all-be-it thin at upper elevations) up to 9,850'.  

*Cloudy day, relatively warm, light SW winds.  No new snow falling today, not even a flurry.


Snowpit or crown profile photo or graph: 
Weather Observations
Blowing Snow: 
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