Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
April 11, 2022
Submitted:
April 11, 2022
Observer:
NWAC Forecaster - Dallas Glass
Zone or Region:
West South
Location:
Bullion/Pickhandle Basins (All aspects near treeline)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

Wind slabs were found in some unusual spots. Fresh slabs were observed on slopes often stripped by the wind.
A snowprofile in the Crystal Backcountry. The storm snow was shallower here due to E winds moving it off the slope.
20-24" of storm snow was generally found over the 4/8 crust.
A small but deep wind slab was triggered by a small cornice fall on this wind stripped slope. The lines below are wind drifts. W, 6400', SS-ACc-D1-R1-S
This small wind slab failed, slid downhill a few inches, and then stopped. W, 6400 ft. SS-ASc-D1-R2-S

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Wind:
Moderate , E
New/Recent Snowfall:
Storm Snow (HST): 20-25 inches, 24 total (HN24) 8-10 inches.

It snowed through nearly my entire tour. Temperatures warmed slightly mid-day. Winds were only really noticeable near the ridgelines. Easterly winds were easily transporting snow.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
3 Apr 11, 2022 11:30 am
() 		Crown Point
E 6300ft 		D1
R1 		SS-Soft Slab S-New Snow AS-Skier
c-Intentional
A small but deep wind slab was triggered by a small cornice fall on this wind stripped slope. The lines below are wind drifts. W, 6400', SS-ACc-D1-R1-S
This small wind slab failed, slid downhill a few inches, and then stopped. W, 6400 ft. SS-ASc-D1-R2-S
Report
Crown Point

I did not see any natural avalanches, but visibility was very poor.

I intentionally triggered 3 avalanches, interestingly these three wind slabs were on W, E, and N aspects.

Snowpack Observations

Storm Snow: The most recent 8-10" (20-25cm) of snow was much stronger and more slab-like than the snow below. This may have been due to higher snowfall rates over the last 12 hours. This layer occasionally produced shooting cracks up to 4ft. Similarly, this layer failed in some uptrack and small slope test, but the slabs remained very isolated to the width of my skis and did not propagate. Other, more inconsistent storm snow layers were also seen. When looking at the bond of the storm snow to the 4/8 crust, in some locations the bond seemed very strong. In others, it failed easily. The limited information from this one tour did not show a noticeable pattern in where the bond is strong verse weak in the Crystal area.

Wind Affected Snow: Near ridgelines it wasn't hard to see wind drifted snow. The Easterly winds today were stripping normally loaded slopes, and building wind slabs in areas that are often scoured. This reverse loading is not uncommon, but this was one of the best examples of it i have seen. Interestingly, I triggered 2 wind slabs on opposite (W and E) sides of the same ridge. One of them was on a slope that showed evidence of wind scouring.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Storm Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
 Layer Depth/Date: 4/8, 20-25"
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
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