Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 24, 2023
Submitted:
January 24, 2023
Observer:
NWAC Forecaster - Matt Primomo
Zone or Region:
East Central
Location:
Upper Entiat (N-E-S 5,500-6,200)

Signs of Unstable Snow

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

Media/Attachments

Very isolated cracking on the skin track revealed weak snow just above the MLK crust.
Some recent, light reverse drifting. The slope to the L is E facing, the slope to the R is W facing.
Raised, small roller on SE aspect. This surface was a thin suncrust at the time of the photo.
Profile on E aspect at 6,100ft.
Large surface hoar found down 51cm.
large, decomposing surface hoar found 51cm down at 6,100ft on E aspect in the Entiat. Test results would sudden collapse.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Wind:
Light , NW
New/Recent Snowfall:
25cm over MLK crust

Valley fog in lower Entiat, clear higher up. Notably warmer above 4k or so with an inversion. Some scattered clouds, winds were calm to light with minimal blowing snow observed.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
3 Jan 15, 2023
() 		Entiat drainage
E ft 		D2 1.5ft N-Natural
Report
Entiat drainage

See attached for a few very widely propagating slides that likely occurred MLK weekend.

Snowpack Observations

Minimal signs of instability today, besides a few fresh rollers on steep SE aspects, as they were becoming moist by early afternoon. We also observed some very isolated cracking with a skin track, that was the weaker snow fracturing on the MLK crust. Obs mainly from 5,500-6,000ft:

Average HS around 150cm. Ski pen 15-20cm, boot pen 25-30cm. Mostly supportable off trail for sleds but deeper in places. Generally nice, soft travel conditions with minimal wind effected snow found.

Surface was mainly surface hoar and near surface facets on N-ESE, with heavier snow and a thin crust forming on SE-S slopes.

Upper Snowpack: Decomposing and faceting recent snow, 25cm over MLK crust. The crust varied in thickness from stout and 6cm thick to a thin and weak 1cm.

Mid pack: Always found large (1cm) layer of surface hoar down around 40-55cm. These were decomposing and rounding some, but still very apparent and easy to pick out with quick hand pits. Hardness 4F to 4F-. CTM SC on this layer.
This layer was on P hard rounds. 15cm down to Xmas crust, which was thick and stout.

Basal pack: I could feel a substantial (30cm) amount of weak snow near the ground on E-N aspects.



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