Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 14, 2022
Submitted:
January 14, 2022
Observer:
NWAC Forecaster - Irene Henninger
Zone or Region:
West North
Location:
Table Mountain (All aspects, 4200-5300ft +)

Signs of Unstable Snow

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

Media/Attachments

Two D2 Glide avalanches which failed on the cliffs at the top of the south side of Table Mountain. The debris piles sat right in the usual transition location for the popular traverse.
A D2.5 avalanche which probably occurred Jan 11-12 in the Baker backcountry. This ran on an easterly slope just southeast of Video Peak, 4900-4100ft elevations.
A D1.5 avalanche which probably occurred Jan 11-12 in the Baker backcountry on a SW aspect just below Table Mountain.
Glide cracks were seen on nearly all aspects and elevations. Here on Mt Herman several small ones are visible. Note the runnels as well.
In many areas I saw a "sparkly surface". I investigated many times, unable to depict any grains other than the frozen surface melt forms, except on Austin Pass where I was able to just barely scrape these 2-3mm needle-like surface hoar forms off the crust.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Temperature:
37°F
Wind:
Moderate , W

Rain died down in the last 24 hours, and temperatures finally reached near/below freezing last night, which froze the snow surfaces solid. Clearing skies midday contributed to warming on southerly aspects. Winds were moderate to strong on the passes/saddles but not as noticeable in other areas.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Jan 12, 2022
() 		Video Peak
E 4900ft 		D2.5
R2 		WS-Wet Slab 2.5ft N-Natural
A D2.5 avalanche which probably occurred Jan 11-12 in the Baker backcountry. This ran on an easterly slope just southeast of Video Peak, 4900-4100ft elevations.
Report
2 Jan 12, 2022
() 		South side of Table Mountain
S 5450ft 		D2
R2 		WS-Wet Slab O-Old Snow 1ft N-Natural
Two D2 Glide avalanches which failed on the cliffs at the top of the south side of Table Mountain. The debris piles sat right in the usual transition location for the popular traverse.
The start zone of the easterly D2 avalanche on the south side of Table Mountain.
The start zone of the westerly D2 avalanche on the south side of Table Mountain.
The debris pile was large and very difficult to travel through.
Report
Video Peak
South side of Table Mountain

Several old avalanches were observed, spanning all aspects and elevations we traveled in- and many were visible at a distance. Most of the avalanches probably ran Jan 11-12. They ranged in size from D1-D3 (small to very large) and all wet snow avalanche types and combinations were seen- glide avalanches, wet slab and loose wet. Many appeared to be around 1 foot deep, however a few notable D2.5-3 were visible at a distance with crown heights probably closer to or at least 5 feet. Some notable large avalanches I didn't include photos of, as they'd already been mentioned in other observations from today.

Snowpack Observations

Runnels were visible on all aspects and elevations of the backcountry. The day started with frozen snow surfaces, with a 5-10cm knife-hard supportable crust. Thankfully it was edgeable on skis. By midday steep south-facing aspects softened as skies cleared, and the snow remained supportable on skis, although now we were sinking 2-3 inches deep. Surfaces were not supportable on foot, sinking in 1-2 feet deep.

We dug a pit at Ptarmigan Saddle on a NW aspect at 5100ft. Beneath the surface crust we found moist-wet melt forms down to about 30cm. 30cm down there was a one inch knife-hard crust, with one inch of wet melt forms above it, where the percolating water appears to have pooled. We suspect in some areas, the avalanches ran on that layer. A compression test yielded a CT21RP on that layer. Beneath that crust we found small rounds (P) which began moist and slowly transitioned to moist-dry by the bottom of our pit at 110cm. The total snow height at the pit location was 410cm.

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