Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 5, 2022
Submitted:
January 5, 2022
Observer:
NWAC Forecaster - Dallas Glass
Zone or Region:
West South
Location:
White Pass/ Hogback Mt (All aspects near and below treeline.)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

Several storm snow layers exist in the upper snowpack.
A snow profile from 1/5. You can see several of the recent interfaces we've been tracking.
Several natural cornice failures occurred over night on 1/4. Some of these blocks are the size of a refrigerator.

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Wind:
Moderate , W
New/Recent Snowfall:
New snow during the day: 1". Overnight: 3-4", Storm Total 28-30"

Very light snow with warming temps. Moderate west winds with light blowing snow at ridgelines.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
3 Jan 5, 2022
() 		Hogback Mt 1st Bowl
S 6200ft 		D1
R1 		SS-Soft Slab S-New Snow 0.5ft N-Natural Report
4 Jan 5, 2022
() 		Hogback Mt 1st Bowl
E 6700ft 		D1
R1 		C-Cornice N-Natural
Several natural cornice failures occurred over night on 1/4. Some of these blocks are the size of a refrigerator.
Report
Hogback Mt 1st Bowl
Hogback Mt 1st Bowl

All the slab avalanches we saw were at the base of cliffs where snow was sifting off the rocks above may have formed stiffer slabs.
Several large natural cornice collapses were observed. Some of them were on small slopes where you might not anticipate a cornice failure.

Snowpack Observations

We found about 2' (60cm) of settled storm snow over the 1/2 interface. This new snow has several layers many of which are up side down. Shovel tilt tests and up-track tests easily highlighted these layers. The new storm snow seems well bonded to the 1/2 interface.

There was plenty of evidence of wind transported snow (scoured slopes, drifts, rime, cornices), but the wind deposited snow was soft and more akin to storm snow. A rim crust was found on windward slopes along exposed ridges.

The snow is settling quickly. We could see this settlement cones and cracks around the base of trees. This corresponds to the 30" of snow now only measuring 24".

Snowpack tests on the 12/29 interface produce sudden results. We did identify 4mm surface hoar at that interface, however no avalanches have been reported on that layer in several days.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Storm Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
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