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Wind Slabs on Gray Butte

Location Name: 
Gray Butte
Mt. Shasta
Date and time of observation: 
Sun, 02/12/2023 - 12:00pm
Observation made by: 
Red Flags:
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain

Location Map

96067 Mount Shasta , CA
United States
41° 20' 50.5968" N, 122° 11' 48.2244" W
California US

Snowpack Observations


My quest for the day was to investigate the sensitivity of wind slabs near treeline and survey snow conditions. I intentionally discovered that wind drifts were reactive to my weight on a northwest aspect at mid-slope and broke along the convexity. I found these slabs ranged in depth from 5 inches - 1 foot, dependent on location. A common characteristic was the pillow-like shape and textured snow surfaces in these locations, which helped to identify the problem. Below the slabs and old snow, a firm bed surface exists on east, south, and west aspects. Solar impacts caused a large rock face to release its hanging pockets of snow which fell to the ground causing roller balls. By mid-day the sun had moistened southerly slopes to a mushy consistency. Cornices displayed signs of settlement in large cracks along the windward side of a northeast ridgeline. Snow conditions are still variable around exposed areas near treeline, with good coverage and uniform conditions below treeline. The wind near treeline was calm with light gusts.     


  • Observation Location: Gray Butte
  • Elevation: 7,800 feet 
  • Date: 2023.02.12
  • Time: 1200
  • Observer: E. Falconer
  • Sky Conditions: Clear (CLR)
  • Current Precipitation: Type - NO
  • Air Temperature: 41 °F
  • Surface Penetration: Ski penetration (PS) = 3 in (5 cm), boot penetration (PF) = 10 in (25 cm)
  • Total Snow Depth (HS): - NO
  • 24-hour New Snow Depth (HN24): - NO
  • 24-hour New Snow Water Equivalent (HN24W): - NO
  • Wind Direction: E-SE
  • Wind Speed: Calm (C), 0 mi/hr | Light (L), 1-16 mi/hr, twigs in motion


  • cracking within the recent wind drifted snow near treeline on a northwest aspect
  • southerly aspect below treeline softening snow at 1100
  • cornice crack indicating settlement near treeline on northeast ridge
  • west and east aspects displaying different surface effects
  • the upper mountain
  • surface clues indicating previous strong northerly winds
  • wind effect on a northwest aspect near treeline
  • hard surface on upper exposed northwest aspect
  • wind effect mid-slope on a northwest aspect
  • roller balls fallen from cliff on southerly slope
  • snow conditions below treeline

Weather Observations


Blowing Snow: 
Accumulation rate: 
Air temperature: 
Above Freezing
Air temperature trend: 
Wind Speed: 
Wind Direction: