Wind affects, weak structure in the lakes basin

TJ bowl area
Submission Info
Friday, February 5, 2021 - 12:15pm
Red Flags: 
Recent loading by new snow, wind, or rain
37° 35' 25.0152" N, 119° 0' 14.7564" W
Snowpit Observations
More detailed information about the snowpack: 

I toured up to about 10,500 ft in the TJ bowl area of Mammoth Lakes Basin today.

I dug in on a west aspect at around 9500’ and found an HS of 160 cm and a very similar structure to what we have found in many areas across the range. A little over 100 cm of right-side-up “new” snow (slab) on top of 55 cm of weak facets. Stability tests are still showing the potential for propagation CT22 SP, and PST42/110END. I also conducted an ECT test with no result though this particular test is becoming unreliable due to the thickness of the slab. (over 1 meter above the weak layer) I gave it one more hit with extra force and saw full propagation. (see video below) This data tells me that the weak layer is still reactive although it will be hard to trigger without a substantial load. A good example is the recent avalanche reported from Hollywood bowl. (see observation here) This avalanche appears to have run on the lower weak layers and may have run during the recent extreme winds on Feb 3.

I observed some evidence of mid-storm avalanche activity off the crest but nothing that appeared to be more recent. Other pertinent observations were limited to surface conditions. Lots of evidence of recent strong winds. Sastrugi, drifting, surface stiffening, recent cornice growth, and a new layer of tree debris all point to recent transport at all elevations.

On slopes with direct solar input this afternoon I observed about 1-2cm of surface saturation at lower elevations, but I would be surprised if enough warming occurred to be concerning today.

I chose to forgo the exposed TJ bowl proper and instead descend via more sheltered terrain. I was pleasantly surprised to find soft surface snow in protected trees near and below treeline. above treeline the wind has left us with a plethora of variable, punchy, and crusty surface conditions.

Snowpit or crown profile photo or graph: 
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Weather Observations
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It was a spectacular day in the mountains today with Warm temperatures, moderate winds, and clear skies. some moderate transport was observed along the crest, however, none was observed NTL or BTL

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