Twin Lakes Conditions & Coverage

Location Name: 
Crater Crest
Region: 
BWRA
Date and time of observation: 
Wed, 12/26/2018 - 14:00
Location Map: 



Observation made by: Avalanche Specialist
Snowpit Observations
More detailed information about the snowpack: 

Went for a sightseeing mission to check overall coverage in the Twin Lakes/Sawtooth Ridge area.

HNS: 1in at lake level with a mostly supportable HS: 8-10in underlying on shady aspects only.  Windward and solar aspects consist of only a dusting of new snow on bare ground.  HNS from 8K-11K: 2-4in (Friday night's snowfall included).   HS from 8K-11K:  ranging from 35-75cm in non wind-affected terrain.  

The snow surface in the area traveled was mostly supportable and varied from dust-on-crust at lower elevations to supportable wind board, medium-hard wind slab, and settled powder at elevations above 8K depending on exposure.  I ski cut and stomped on newly formed wind slabs that remained welded in place.  The snowpack was entirely non-reactive with only localized cracking (directly underfoot) and no signs of instability observed.  

The NSF/crust combination that has produced a handful of avalanches throughout the Sierra in the past couple weeks is present in this area, however currently seems to lack enough widespread connectivity to be problematic.  It will be a layer to monitor when we receieve a significant new load on the snowpack.  

Photo 1: Shallow, supportable snowpack climbing from Twin Lakes.

Photo 2: A dusting of graupel was present at the new snow/old snow interface that made for slippery skining in areas where it accumulated on supportable wind board. 

Photo 3: Wind-influenced snow pack (or lackthereof) in exposed alpine terrain.  

Photos 4-6: Current coverage on lee aspects above Twin Lakes.

 

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Northwest
Accumulation rate: 
None
More detailed information about the weather: 

Calm day above Twin Lakes.  A light NW wind was present only above 10K on exposed ridgelines.  Little/no snow transport observed.