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New Crust And New Snow

Location Name: 
Northwest aspect of Gray Butte
Region: 
Mt. Shasta
Date and time of observation: 
Fri, 01/13/2023 - 2:00pm
Observation made by: 
Forecaster
Red Flags:
Recent avalanche activity
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path

Location Map

96067 Mount Shasta , CA
United States
41° 20' 53.9592" N, 122° 11' 42.8424" W
California US

Snowpack Observations

Details

After reading the forecast and the previous day's observations, I wanted to assess the snowpack for a potential new crust layer and how it was interacting with the new snow. I chose to ascend Gray Butte, where I could look at multiple aspects for the distribution of the crust. Lots of snow was encountered on the road up to Mount Shasta Ski Park. While heading up the lifts, it was snowing even harder. At one point, it was snowing at least an inch an hour (S2).

Up on Gray Butte, the crust became prevalent on all aspects. Skinning conditions became a little challenging with the new snow easily sliding on the very firm crust. Cornices had grown on the northerly aspects.

A pit was dug to further look at the new crust. The crust appears to be anywhere from 1 cm to 3 cm thick. Variance in thickness is probably due to the aspect and amount of warming that had occurred. About 12 inches of new snow was found on top of the crust. An ECT was performed, where full propagation occurred on tap 14 just below the new crust. 

While skiing down, I pushed multiple small point-release wet loose avalanches on steeper slopes. Though these were harmless, they could travel far and entrain lots of snow below.

On the way out, the snow became more saturated, and it appeared to be raining in the parking lot. 

  • Observation Location: Northwest aspect Gray Butte, just below the ridge
  • Elevation: 7800 feet
  • Date: 20230113
  • Time: 1400
  • Observer: S. Clairmont
  • Sky Conditions: Obscured (X)
  • Current Precipitation: Type - SN, Rate - S2
  • Air Temperature:  28 °F
  • Surface Penetration: Boot penetration (PF) = 48 in (122 cm)
  • Total Snow Depth (HS): 295 cm
  • 24-hour New Snow Depth (HN24): 9 in (22 cm)
  • 24-hour New Snow Water Equivalent (HN24W): 1.7 in (4.3 cm)
  • Wind Direction: SE
  • Wind Speed: Moderate (M), 17-25 mi/hr, small trees sway
  • Column & Block Tests:
    • Slope Angle & Aspect: 38º, NW
    • ECTP14 ↓ 14 in (35 cm)

Photos

  • Visibility conditions
  • Crust density
  • New crust
  • Bent trees
  • Surface conditions
  • Snow pit
  • Snow pit with new crust
  • New crust appears thicker on this wall

Weather Observations

Statistics

Cloud Cover: 
100% of the sky covered by clouds
Blowing Snow: 
Yes
Precipitation: 
Snow
Accumulation rate: 
Greater than 1 in. per hour
Air temperature: 
Below Freezing
Air temperature trend: 
Static
Wind Speed: 
Moderate
Wind Direction: 
Southeast