Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
December 28, 2021
Submitted:
December 28, 2021
Observer:
NWAC Forecaster - Matt Primomo
Zone or Region:
East Central
Location:
Mt Cashmere

Signs of Unstable Snow

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

Media/Attachments

Profile at 6,800ft in the East Central Zone. Weak snow from early December showed potential to create deep avalanches in this area.
Recent, shallow windslab underneath a cornice. If you look closely you can see that the slide may have stepped down to a deeper layer.
Graphed profile, same site as annotated photo

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Wind:
Calm

Cold temps, sun came out for a bit. Scattered mid and high level clouds with some very light snow falling at times.

Observed one recent D1.5 wind slab that may have stepped down to a deeper layer on a N aspect at 7,200ft below a cornice. See photo.

Snowpack Observations

Snowpack depth ranges from 150-170cm in the area above 6,000ft. Found evidence of recent light wind drifting from the SW.
Decembers storm snow appeared well bonded and gradually gets harder down to Pencil, until a thin crust from earlier in December. Walking around with a probe, I could feel weaker snow between crusts on a variety of aspects (W-N-E) from 6-6,800ft. This layer is down 110cm-130cm in the area.

Profile at 6,800ft on a NW aspect, 30 degrees.
HS 166cm.
12/21 down ~45cm, found as slightly more firm old snow. CTM RP (Q2) here on decomposing fragments.
12/8 down 115cm. CTH SC, DTT M SC, and PST 45/115 (End) on faceted melt forms just beneath a weak melt freeze crust.
Though it appeared unlikely, this poor structure near the base of the snowpack kept us off bigger features.

From 4,500ft-5,500ft in the trees we found 30-40cm over the crust from the Solstice. Weaker snow is forming right above the crust (~1mm FC).

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