Observation: Public

Observation Details

Signs of Unstable Snow

Observations

Time: 10:30
Conditions: OVC (overcast)
Location: Lower Sno-Park South Tahoma Trails (46.7063, -121.9934)
Snow conditions:
- wet loose/unconsolidated (sprinkling at lower elevations).
- No visible stability or instability.
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Time: 11:30
Conditions: OVC
Location: Past Upper Sno-Park South Tahoma Trails (46.6928, -122.0116)
Snow conditions:
- wet loose/unconsolidated (sprinkling at lower elevations).
- larger volume snowpack.
- wet loose conditions observed with pinwheels/rollerballs.
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Time: 12:30
Conditions: X (obscured)
Location: 46.6866, -122.0256 (Ben Jones loop cut-off)
Snow conditions:
- heavy, wet storm snow.
- snowshoes sank around 1' down off groomed track.
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Time: 12:45
Conditions: X ; RA/PP (rain; sprinkling)
Location: High Hut/Anderson Lake road junction (46.6844, -122.0338)
Snow conditions:
- storm/wind fetch snow.
- snowshoes sank ~1' down off groomed trail.
- ~2' broken crowns on north/eastern side of ridge.
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Time: 14:00
Conditions: X ; RA/PP (rain; sprinkling)
Location: High Hut
Snow Conditions:
- undisturbed snowpack off trail compressed ~3" with snowshoes.
- wind loaded on east side of ridge.
Comments:
Dug basic pit to discuss overall motivation and demonstrate relative pressure test, practice digging pit, demo quick and dirty isolated column test, etc.

Due to time constraints and location, pit wasn't cleanly dug, but the general observations seemed to be as follows:
* Location: High Hut: 46.6966, -122.0260
* Snowpack: ~144cm to base.

Relative pressure test:
* 144-136cm: new rain crust (fist)
* 136-130cm: storm snow (fist)
* 122-119cm: finger+
* 119-109cm: finger
* 109-107cm: hard rain crust (ice; could not disturb)
* 107-78cm: 4 finger
* 78cm: finger+

ICT (isolated column test):
* CTM (moderate) /PC (progressive compression) (Q2) at 18 loading steps at 136cm.
** Non-planar break

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Time: 16:00
Conditions: BKN (broken skies)
Location: Lower Sno-Park South Tahoma Trails (46.7063, -121.9934)
Comments:
* No new snowpack instabilities observed.
* Temperature had warmed since start (approximately 3-5 degrees F warmer).