Professional Field Report

Basic Information

Observation Details

Observation Date:
January 19, 2020
Submitted:
January 19, 2020
Observer:
SAC - Martin Stefan
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Mushroom / Gladiator

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
Isolated
Isolated collapses on wind stiffened snow on top of Gladiator ridgeline. Small avalanche on Senate ridge that looked fresh, see below.

Snow Stability

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

Bottom Line

Buried persistent weak layers are still a concern, giving snappy results on my tests. Wet activity on solars as a secondary concern.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
high 20s est
Wind:
Calm

Solars getting baked and heavy, but not wet were we travelled. However a lot of small loose/wet activity could be seen in the Boulders from hwy

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Germania
 U Very big slide, spans a large part of the mountain. Photo taken from summit of Gladiator. From the crown size I would assume it was part of the big deep slab cycle last week.
Very large avalanche, probably from 1/12 - 1/17 deep slab cycle. Estimated location 4th of July drainage, taken from summit of Gladiator.
1 Senate Ridge
W 9600' approx 		D1.5 U SS (?) pocket potentially triggered by cornice drop.
D1.5 pocket on Senate Ridge W face around 9600', potentially triggered by cornice drop

Snowpack Observations

The snow took a lot of radiation today, but air temps remained cool enough to provide cold snow in the shade.

Gladiator 9500' SSE not obviously wind stiffened. HS 105cm (wanted to see how PWL:s are reacting to radiation)
10cm moist DH at gnd, patchy MFcr on top, not consistent enough for PST or to cover a full ECT column.
Faceting of various degrees up to 46cm, 4F -F hardness.
12/31@46cm as 2cm of larger facets, 2-3mm. PST30/100end
Above 4F -> F wind/stormslabs with an interface at 60cm that gave ECTN

Stomped a few cornices but no real crack propagation. Lots of wind effect above tree line, from several directions and hard to predict but did not seem very reactive.

Several wet/loose slides in the Boulders spotted from hwy, many/most steep solars under rocks or oven features sloughed out during the day.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: 40-80cm, 12/31
Comments: Unreactive on s1/4 mid elevation terrain where slab is faceted, reactive at higher elevations where wind effect is more prominent. Did not travel on N 1/2 today

Terrain Use

Open terrain sub 30, treed terrain mid to lower elevation in lower 30s