Snow Profile and Wind Slab Sensitivity in the TJ Bowl Area

SNOWPACK OBSERVATION Mammoth Lakes
Submission Info Forecaster Monday, December 4, 2017 - 12:30pm

Contributor

Clancy Nelson

Red Flags:

Recent loading by new snow, wind, or rain

37° 34' 55.56" N, 119° 0' 14.04" W

See map: Google Maps

Snowpit Observations

More detailed information about the snowpack:

Toured up towards the Mammoth Crest Near TJ Bowl to test the sensitivity of recent wind slabs and dig another snow profile to track how the cold temperatures were affecting the shallow snowpack. Cold out there today! 10 deg. F at noon. Mostly calm with occasional light E winds. Some localized creeping snow dancing across the surface. Steady moderate E winds all day transporting snow towards the W on the top of the Crest (see photo of the Crest). Snow below 10000' was soft mixture of wind blown and graupel from yesterday with near surface facets developing underneath. Some soft, shallow (approx. 5cm) wind slabs on N and W aspects. Above 10000' snow surface was a jigsaw puzzle of breakable wind board, soft wind deposits, and firmer but still shallow wind slabs. Test slopes had some localized cracking (see the photo of my foot). Didn't bother ascending the Crest above 10400' because of the breakable crust and talus poking through in most places. Snow depth at 10400' averaged about 50cm. Descended a little to get a more average snowpack and dug a profile at 9990'. The cold air that has settled over the area is driving a much steeper temperature gradient in the shallow snowpack than even yesterday. Grains that were round yesterday are already showing some angles and acting like sugar crystals. Still, all of my tests were inconclusive. Didn't see any other signs of instability. But it will be interesting to see how weakened the snow becomes with the cooler temps.

Snowpit or crown profile photo or graph:

Snowpack photos:

Moderate E winds transporting snow at the top of the Crest.

Localized cracking in shallow wind slabs.

Weather Observations

Blowing Snow:

Yes

Cloud Cover:

Clear

Air temperature:

Below Freezing

Wind Speed:

Moderate

Precipitation:

None

Air temperature trend:

Static

Wind Direction:

East

Accumulation rate:

None

More detailed information about the weather:

Almost all blowing snow confined to the top of the Mammoth Crest at 11300'. I expect areas that actually have W facing slopes at and above that elevation were developing more wind slabs today.