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Avalanche Gulch - Lower Casaval

Location Name: 
Mount Shasta
Mt. Shasta
Date and time of observation: 
Sat, 02/20/2021 - 11:30am
Observation made by: 
Red Flags:
Whumphing noises, shooting cracks, or collapsing

Location Map

96067 Mount Shasta , CA
United States
41° 22' 55.1748" N, 122° 13' 39.2808" W
California US

Snowpack Observations


The storm broke early this morning and gave way to an exquisite day. Lingering misty clouds did little to block the bright blue sky. There was some notable wind, especially above the treeline. Light winds were observed up to 9,000 on Lower Casival Ridge. The pesky northwesterly wind was visible at higher elevations for most of the day.  Blowing snow was actively loading easterly slopes. The wind was funneling down the gullies causing variable wind directions and speeds for lower elevations.

  • Observation Location: Lower Casaval- Mt. Shasta
  • Elevation: 6,950 to 9,000 feet.
  • Date: 20210220
  • Time: Late morning to afternoon
  • Observer: R Sorenson
  • Sky Conditions: Few
  • Current Precipitation: NO
  • Air Temperature: 26.5°F high temp at 1300 hours
  • Surface Penetration: Boot penetration (PF) = 10-12 in (25-30 cm). Ski penetration (PS) = 6 in (15 cm)
  • Total Snow Depth (HS): 66 in (170 cm)
  • 24-hour New Snow Depth (HN24): 3 in (7 cm)
  • 24-hour New Snow Water Equivalent (HN24W): 0.23 in
  • Wind Direction: SE 
  • Wind Speed: Variable, Light limited and localized blowing and drifting snow. Gusts to moderate with blowing snow transported by saltation and turbulent suspension. 
  • Column & Block Tests:
    • Slope Angle & Aspect 20º, SE
    • CT9 ↓ 15 cm Q1 SC
    • CT16 ↓ 60 cm Q1 SP
    • ECTN11 ↓ 6 in (15 cm) 

We dug a pit on the southeast flank of Casaval Ridge, near treeline. Eight inches (20 cm) of fist hard snow from the series of storms on Thursday and Friday (2/18 and 2/19). This sits atop an inch thick (5 cm) crust. All of which is above 15 inches of fist to 4 finger hard snow sitting on a hard melt-freeze crust from January. Column tests produced planar results with moderate force within the new snow and on a density change down 23 inches (60 cm) but did not propagate in extended column tests. Snow surfaces were soft and smooth below and near treeline, but a transition to slightly wind-affected surfaces was noted above treeline. Some cracking and blocking were seen on the skin track as we traversed a southeast aspect above treeline. 



  • Avalanche Gulch, near treeline
  • Wind affect on westerly aspect of Green Butte
  • Ski penetration (PS) =  3 - 6 in
  • ECTN11 ↓ 6 in (15 cm) 

Weather Observations


See notes above.


Cloud Cover: 
25% of the sky covered by clouds
Blowing Snow: 
Accumulation rate: 
Air temperature: 
Below Freezing
Air temperature trend: 
Wind Speed: 
Wind Direction: