Northwest Avalanche Center

Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
November 24, 2021
Submitted:
November 24, 2021
Observer:
NWAC Forecaster - Andrew Kiefer
Zone or Region:
Mt Hood
Location:
Palmer Glacier (5800-9800ft E-S-W aspects)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

A snowcat undercut a wind loaded gully (E, 7500ft) and triggered a hard slab 18in thick and 30ft wide. The slab fractured and arrested before sliding onto the groomed track.
Wind textured snow, scoured ridgelines, and thick wind drifts on leeward slopes looking up the southside of Mt Hood.
Chalky turns on the Triangle Moraine

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Temperature:
35°F
Wind:
Light , SW
New/Recent Snowfall:
11/22-23 HST 12-15in

Clear skies early with high thin clouds by 11am. Cool start to the day with freezing levels rising to 8000ft by noon. Mostly sunny skies and light winds made for pleasant conditions.

No new avalanches observed. A snowcat undercut a wind loaded gully (E, 7500ft) and triggered a hard slab 18in thick and 30ft wide. The slab fractured and arrested before it could slide onto the groomed track (see photo).

Snowpack Observations

During the recent storm (11/22-23) snowlines dropped to near 3500ft with 8-10in of new snow near 4500ft and 12-16in of new snow 6000ft and above. Near and above treeline, the new snow was heavily affected by strong southwesterly winds. Many ridgelines were scoured down to dirt, and easterly slopes held thick and firm drifts. Snow depths were variable, but in areas above 7000ft with continuous coverage, the height of snow averaged about 2-3ft. New and wind drifted snow generally appears well bonded to old snow surfaces. Hand pits and small column tests resulted in resistant planar fractures and non-planar breaks. Skiing conditions improved since the weekend and it was possible to find smooth chalky turns in some places. Rocks and icy surfaces were still challenging to avoid.

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