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Professional Observation

Basic Information

Observation Details

Observation Date:
March 26, 2020
Submitted:
March 27, 2020
Observer:
SAC - Savage - OFF DUTY/REC
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Smiley Ck area and glassing Ketchum-southern Sawtooths: 7200-9300', all aspects but mainly SW-W-NW-N

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
Only cracking was a few tiny cornice blobs I played with.

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
Moderate
Stability Trend: 

Bottom Line

About 6-12" of new storm snow in the Frenchman/Smiley/Beaver Ck area from 7500 to >9000'. Not much wind in this area during or after the storm, so very little natural avalanche activity. There was a fair amount of new, soft cornice growth on the ridges. The mid-storm instabilities were not breaking cleanly like they were in the northern Sawtooths and Banner Summit area the past few days. Exposed W and SW aspects over 8500' got plenty of sun today, cooking the new snow down to a few inches of glop on a firm crust - you probably could have triggered wet loose slides there today in very steep terrain, but it may not be as much of a problem Friday and Saturday.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Temperature:
teens F?
Wind:
Light , NW

Mostly clear skies until late afternoon when convective clouds rolled in from the west. Temperatures never rose very much, staying cold enough to keep the feet cool. Guessing around 10F above 9000' at 3-4 PM?

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
15 Past 48 hours Alpine Ck, Cabin Ck, McDonald Peak area, Vienna area
E alpine 		D1 L N-Natural Most were D1, maybe a few D1.5. Most were triggered by small natural cornice fall. Focused on E aspects, some NE too. None
1 Past 48 hours Galena Peak
W 10200 		D1.5 SS N-Natural W-SW aspect, failed well below ridgeline.
(3-26-20) This small slab avalanche failed during the recent storm on a W-SW aspect on Galena Peak.
1 Past 48 hours Beaver Ck - Eureka Peak/point 10129
E 10000 		D1.5 SS N-Natural E-NE aspect. It looked like it went when hit from above by small loose snow slides (sluffs).
(3/26/20) This small slab avalanche failed on an E-NE aspect near 10000' in the Beaver Creek drainage during the recent storm. It may have failed when hit from above by sluffs.
1 Past 24 hours Above Titus Lake trailhead
NW 9400 		D1 SS N-Natural N-NW aspect. Likely trigger was small cornice failure.
(3-26-20) This small slab avalanche failed on a N-NW slope near 9400' near the Titus Lake trailhead.

Snowpack Observations

2" storm snow at Smiley Creek valley floor, increased to 6-12" from 7500-9300'. Very little wind effects other than soft cornice growth and super soft slabs at ridgelines but not extending very far at all downslope. All the storm snow was fairly low density. Storm snow has bonded fairly well to old crusts on solar aspects. The old/new interface wasn't too faceted on shady aspects, but there were multiple crust+FC layers below the storm snow on shady aspects below about 8300'. The dirty 3/7 FC layer wasn't as prominent here as we've seen in the Baker Ck, Northern Sawtooths, and Banner Summit areas - not sure why?
Snowpack tests: no standard tests performed - strictly small columns, pulling and tapping with hands. No Q1 shears within new snow, at old/new interface, or in 3/7 layer (few tests/observations of 3/7).

Avalanche Problems

Hard to say what the main problem was today. Cornices grew and were soft - you could have fallen off one if you weren't paying attention. Wet loose issues were becoming possible on SW and W, but the cold temps+consistent light breeze+clouds rolling in kept them subdued. Sluff management would have been an issue in very steep terrain, and some sluffs could have triggered small, soft wind deposits on the way down.

Terrain Use

We skied non-wind loaded terrain up to about 35 degrees. We avoided steeper solar slopes (possible wet loose issues and ski quality) and very steep, exposed shady slopes (group objectives and minimal observations on 3/7 layer).

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