Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
December 27, 2021
Submitted:
December 27, 2021
Observer:
NWAC Forecaster - Andy Harrington
Zone or Region:
Snoqualmie Pass
Location:
Alpental Valley

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

Multiple shallow soft slabs were observed throughout the Alpental Valley on 12/27. Often, they were interspersed with loose avalanches, making it difficult to discern between the two.
Recent loose avalanches were plentiful and easy to spot throughout the Alpental Valley on 12/27, even with a skiff of new snow on their debris piles.
Drifting behind natural features showed that the winds have been moving snow recently, likely forming Wind Slabs on nearby terrain. Blocks of snow and ice in rocky terrain are precariously perched waiting for the right time to fall on the slopes below, possibly triggering avalanches
We'll keep an eye on the weak upper snowpack until it snows again.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Wind:
Calm
New/Recent Snowfall:
~4"

Beautiful day with minimal to zero wind, but very cold temperatures. Broke out my east coast ski layers for touring today. Plenty of low-density snow available for transport and the few light gusts we experienced moved it around easily.

Observed more recent avalanches than I could count. Almost every feature had some sort of sign of a recent avalanche - whether it was a slab or a loose. Trees and rocks shedding had fan shaped debris piles below them. Steep or unsupported rocky terrain has shallow slabs and loose avalanches mixed together. A larger avalanche was confirmed up near the Thumbtack in Upper Chair Peak Basin.

Snowpack Observations

Very low-density snow has consolidated some in recent days. As we approached the top of Pineapple Pass, wind stiffened snow was easy to identify under the HN. Plenty of signs of recent wind effect.

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