Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
March 10, 2022
Submitted:
March 10, 2022
Observer:
NWAC Forecaster - Andrew Kiefer
Zone or Region:
Mt Hood
Location:
Illumination Saddle (5800-9600ft, E-S-W aspects)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

Natural avalanche activity on the West Face/Leuthold Couloir on Mt Hood. All avalanches appeared >24hrs old
A large natural avalanche released on rock slab below Crater Rock with debris running 1200ft onto the Zig Zag Glacier near Illumination Saddle. The avalanche occurred sometime 3/6-9.
35cm of wind affected snow well bonded to the Early March Crust.
The crown of a natural avalanche that ran a few days ago below Illumination Rock
A large opening crevasse on the White River Glacier.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Temperature:
30°F
Wind:
Extreme , W

Thin high clouds with filtered sunshine. Steady 10-20mph W'ly winds up to the top of Palmer. Increasing wind speeds above with gusts over 50mph at Illumination Saddle. Blowing snow and spindrifts above 8500ft.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
10 Mar 8, 2022
() 		West Face/Leuthold Couloir
W 10600ft 		D1.5
R1 		N-Natural
Natural avalanche activity on the West Face/Leuthold Couloir on Mt Hood. All avalanches appeared >24hrs old
Report
1 Mar 8, 2022
() 		Illumination Rock
SE 9200ft 		D1.5
R2 		SS-Soft Slab I-New/Old Interface 0.5ft N-Natural
The crown of a natural avalanche that ran a few days ago below Illumination Rock
Report
1 Mar 8, 2022
() 		Hot Rocks/Upper Zigzag Glacier
SW 10400ft 		D2
R2 		HS-Hard Slab G-Ground 1ft N-Natural
A large natural avalanche released on rock slab below Crater Rock with debris running 1200ft onto the Zig Zag Glacier near Illumination Saddle. The avalanche occurred sometime 3/6-9.
Report
West Face/Leuthold Couloir
Illumination Rock
Hot Rocks/Upper Zigzag Glacier

A large natural avalanche (D2) released from the Hot Rocks with debris running 1200ft onto the Zigzag Glacier near Illumination Saddle. The avalanche occurred sometime 3/7-9; observers in the immediate area on 3/7 did not see the avalanche. Several 6-12in deep natural winds slab and loose dry avalanches (mostly D1.5) were visible on the West Face/Leuthold Couloir and adjacent gullies. These avalanches all appeared >24hrs old.

Snowpack Observations

These observations were taken at higher elevations than where the NWAC forecast applies to support ongoing SAR operations on the west face of Mt Hood.

Up to 30cm of heavily wind affected snow was well bonded to the Early March Crust. The 3/8 interface was identifiable with hand pits and shovel tilt tests, generally ↓10cm. In most areas above 7500ft, there was a hollow-sounding, upside-down layering configuration with 1F hard snow above 4F hard snow at the 3/8 interface. Tests targeting 3/8 resulted in RP fractures with hard force. These wind slabs are shallow, a couple days old, and appear stubborn to triggers, but I wouldn't want to be on an unsupported loaded alpine slope greater 40 degrees. In exposed areas, the snow surface was firm and icy, but still edge-able going downhill.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: 10-30cm, 3/8
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