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Professional Observation

Basic Information

Observation Details

Observation Date:
January 20, 2020
Submitted:
January 21, 2020
Observer:
SAC - Stefan (off duty), Mannberg
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Central Boulders

Signs of Unstable Snow

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

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Low
Stability Trend: 
Steady

Bottom Line

Storm slabs have stabilized, mid-pack persistant weak layers unreactive to my tests but monsters in the basement still present

Media

Depth hoar (very weak sugary snow) found at 9700' NW aspect in central boulders.

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Temperature:
mid 20s est
Wind:
Light , SE

Overcast but warm, periods of very light snowfall but no accumulation. Crust on solar slopes from Sunday.

Snowpack Observations

At mid to low elevs S -> W we have the usual soft slab with facets underneath, HS 60-80cm, ski pen depending on amount of wind press either 10cm or down to sage. No crusts in snowpack, sun crust on surface on exposed solars.

High elevs obviously wind affected from several directions, difficult to find a representative spot.
9700' NW HS 100cm
Basal facets/DH bottom 10cm, F hard, look well developed size >3mm and a very subtle crust/higher density and smaller facets on top. PST45/100 end on this layer.
Various windslabs in different degrees of faceting up to 70cm, 4f-K hardness, but no results in the interfaces between.
At 70cm 3cm FC (12/31?) under yet another 1F windslab some 5cm thick, no results on tests.

Above 70cm various generations of windslabs, RG F - 1F. ECTN at 80cm ininterface between wind slabs.

Wind has probably done too much work here to extrapolate much useful about mid pack PWL:s, but result on basal facets despite lack of crust is notable.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
 Layer Depth/Date: 11/26, 12/7, 12/31, 30-90cm
Basal facets was main concern where I was yesterday, but previous obs point to a variety of other layers, most notably 12/31 on more solar aspects at mid-high elevs. In general problem is confined to where wind has formed slabs, which is most upper elevs and a large part of exposed or sparsely treed mid elevs.

Terrain Use

We avoided avalanche terrain wherever there was a chance the wind had got to the snow.

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