Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 1, 2023
Submitted:
January 1, 2023
Observer:
NWAC Forecaster - Dallas Glass
Zone or Region:
West South
Location:
Mt Rainier, Paradise Area (E-S-W aspects Below, near, and above treeline. 5200-7600ft. )

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

Cross-loaded mid-slope features like this can suprise travelers with wind slab avalanches.
Rollerballs below trees shedding snow.
Sharp cornices, wind lips, and drifts on a ridgeline from recent strong westerly winds.
Surface hoar (5mm) was seen on most slopes near and below treeline. On steep sunny areas the surface hoar melted down during the day.
Open creeks were prevently after the Chrsitmas rains.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
29°F
Wind:
Calm
New/Recent Snowfall:
Storm Total: 30+ inches. In sheltered locations we found 30in (75cm) of settled snow over the Christmas Crust

Beautiful day! Clear skies, cool temperatures, sunshine, and calm to light and variable winds.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Dec 30, 2022
() 		Wilson Bench
E 7800ft 		D2.5
R2 		HS-Hard Slab N-Natural
An older avalanche from a steep convex rollover on the Wilson Bench. This slide propagated widely. Unknown release date. E, 7800ft.
Old and new avalanches between 7800-10000ft on E-SE aspects
Report
1 Jan 2, 2023
() 		Upper Cornice, Panorama Pt
E 6800ft 		D2
R2 		HS-Hard Slab NC-Cornice Fall
A natural cornice triggered wind slab avalanche near Panorama Pt, Mt Rainier. SE, 6800ft. HS-NC-D2-R2-U
A natural cornice triggered wind slab avalanche near Panorama Pt, Mt Rainier. SE, 6800ft. HS-NC-D2-R2-U
A natural cornice triggered wind slab avalanche near Panorama Pt, Mt Rainier. SE, 6800ft. HS-NC-D2-R2-U
Report
3 Jan 1, 2023
() 		Edith's Knob: SE 5800ft
SE 5800ft 		D1.5
R2 		WS-Wet Slab 0.5ft NL-Loose Snow avalanche
Natural rollerballs, loose wet, and small wet slab avalanches. SE, 5800ft. WS-NL-D1.5-R1-S
Natural rollerballs, loose wet, and small wet slab avalanches. SE, 5800ft. WS-NL-D1.5-R1-S
Natural rollerballs, loose wet, and small wet slab avalanches. SE, 5800ft. WS-NL-D1.5-R1-S
Report
Wilson Bench
Upper Cornice, Panorama Pt
Edith's Knob: SE 5800ft

Snowpack Observations

Above Treeline: Strong westerly winds this past week significantly redistributed the recent snow. Some westerly slopes are scoured to the Christmas Crust. Similarly drifts 3-4ft deep were seen. Southerly aspects were warming above treeline with snow shedding from rocks. We were not out during the warmest part of the day. We only saw a few piles of rollerballs and small loose wet avalanches at upper elevaitons.

Near Treeline: Obvious signs wind transport (recent avalanches, sharp cornices, drifts, textured surfaces, and pillow-like slabs) were seen throughout the elevation band. Direct loading occurred onto NE-SE aspects, however cross-loading was observed on a variety of aspects including W and SW.
Snow on steep sunny slopes became moist during the day with some rollerballs and small loose wet slides around noon.
Surface hoar was seen throughout the elevation band and appeared to survive in places not receiving direct sun.
In general, we found 25-35 inches (65-80cm) of snow over the Christmas Crust.

Below Treeline: Minimal signs of wind loading at the upper edge of the elevation band. Numerous rollerballs on SE-SW slopes (less on E and W). Loose wet activity was limited to a few small but steep slopes.

Other: Large creek holes were seen near and above treeline with water running high and fast.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wet Loose
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Comments: We likely didn't see the peak Loose Wet problem that occurred in the afternoon.
Wind 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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