17-Jan Obs and Snow Pit Above Koenig Lake

Location Name: 
Above Koenig Lake
Region: 
BWRA
Date and time of observation: 
Tue, 01/17/2017 - 12:30
Location Map: 



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

Rode up to Leavitt Lake on Tuesday and found a variety of snow surfaces, including very large surface hoar crystals in sheltered meadows, moist snow and roller balls on exposed southerly facing slopes, dry and somewhat consolidated snow on shaded northerly slopes, a thin wind board on upper elevation exposed slopes, and a thin sun/melt-freeze crust near the end of the day on exposed southerly slopes.  I ascended the ridge between Leavitt and Koenig Lakes and dug a pit in the narrow NW facing bowl on that ridge which looks down towards Koenig Lake.  The snow was very well consolidated with the exception of a layer of softer snow 55 cm below the surface.  Surprisingly, this layer propogated with a sudden collapse both times during 2 ECTs I performed (ECTP 24/26).  The suspect layer was a softer layer of decompsing new snow and rounded grains that seemed have been overlayed by some more dense snow, like a wind slab, last week (i.e., an upside down density change in the snowpack).  Though no persistent weak layers were associated with this layer and it took some force to initiate, the fact that this layer was able to propagate a failure should be a red flag that some instability still exists in the snowpack and, if hit in the right place, could trigger an avalanche.  I expect this layer to consoldate and gain strength over time, but may be reactive during the next storm before that happens.

Picture Captions:

1: Large fields of surface hoar, with a zoomed in photo of a 10 mm surface hoar chain.  Luckily, these were not found higher up in avalanche terrain

2:  A large rollerball on a SE facing slope, caused by of moistening of the snow surface and indicative of possible wet loose avalanche potential

3: Soft snow could still be found on shaded northerly slopes, like this one between Leavitt and Koenig Lakes

4: Moderate NW winds began to pick up and transport dry loose snow

5:  Good riding conditions can still be found in the BWRA

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Air temperature trend: 
Cooling
Wind Direction: 
Northwest
More detailed information about the weather: 

Periods of high clouds and off and on again wind gusts from the NW.  Temps were well above freezing at 10k ft