Professional Observation

Basic Information

Observation Date:

March 20, 2023

Submitted:

March 21, 2023

Observer:

Geoff Unger | Key Observer

Zone or Region:

Mammoth Lakes

Location:

Evidence of Natural Windslabs on the Crest and Snowpack Observation

Recent Avalanches?

Yes

Cracking?

Isolated

Collapsing?

None Experienced

We toured into the Lakes Basin to get a look at mid and upper elevation terrain today and conduct a snow profile observation. Here is what we found supported by photos.

Evidence of windslab up to D2 that ran naturally during the loading event yesterday.
Wind was actively transporting snow at the sherwin ridge in the morning as we toured by.
Wind texture was present in exposed areas
Informal kick tests produced isolated cracking in the upper 30-40cm of the snowpack
Snow profile and column tests indicated it is possible to initiate a fracture in a week layer buried 30-40cm down, but that propagation was less likely due to weak overlying slab. This was in sheltered terrain only. Avalanche observations would indicate a strong enough slab where wind transport was evident.
Soft surface snow with Graupel up to 3.0mm

Stability Rating:

Poor

Confidence in Rating:

High

Stability Trend:

Worsening

Advanced Information

Cloud Cover:

Mostly Sunny

Temperature:

-2.0 C

Wind:

Moderate , W

Field Weather Observation

Location	Pano
Time	1451
Elevation	8700
Aspect	S
Sky	X
Tair/Tsurf/T20	-2.5
Precipitation Type/Rate	SN S-1
Wind	M -> W
Blow Snow	M
Surface Form/Size	PPgp 2.0
HST	Tr
HS	163
Pen Boot/Pen Ski	25/5
Comments

#	Date	Location	Size	Type	Bed Sfc	Depth	Trigger	Comments	Photo
8	Past 24 hours	Mammoth Crest NE 10,500	D2	SS	I-New/Old Interface	40cm	N-Natural

20230320 Snow Profile, Lake Mary