Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Andrew Kiefer
Observation Date:
December 10, 2020
Submitted:
December 11, 2020
Zone or Region:
West North
Activity:
Skiing/Snowboarding
Location:
Bagley Lakes/Artist Point

Observed Avalanches

Did you observe any avalanches? 
Yes
Avalanche Type:
Wet Loose
Size:
Size 2: Could bury, injure, or kill a person
Elevation:
4500
Aspect:
N
Comments:
Large wet loose avalanches on the north aspect of Table Mountain
Photo:

Signs of Unstable Snow

None reported

Observations

A wet avalanche cycle occurred December 7-9 as over 3 inches of rain saturated the snowpack. Wet loose avalanches entrained significant snow as they ran downslope and some grew large. A few glide avalanches (the release of the entire snowpack as a result of gliding over a lubricated ground surface) also occurred in areas of shallow snow covering smooth rock slab. Most avalanches ran in northerly terrain above 4500ft where rain fell on a drier snowpack.

Fortunately, the cooling trend allowed the snow surface to refreeze (12/9 crust), and the snowpack to gain strength. Pulses of new snow since Wednesday night have improved travel conditions, and the new snow appears well bonded to the crust below.

Media

Several large loose wet avalanches converged to make one nasty debris pile on the north aspect of Table Mountain. The avalanches ran sometime between December 7-9.
Heather Meadows weather station data December 1-10 (Temperature, Precipitation, Snow Height)

Advanced Observations

Observed Avalanche Problem #1: 
Wind Slab
Comments: 
Southwesterly winds redistributed 10cm/4in new snow into small and shallow wind slabs in lee alpine terrain.
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