Date of Observation: 11/09/2021
Name: Eric Murrow
Zone: Northwest Mountains
Route Description: Northerly side of Purple Ridge. Ascended from the head of Slate River Valley.
Observed avalanche activity: No
Avalanches: None
Weather: Partly to mostly cloudy. Light winds and mild temperatures.
Snowpack: The goal of this trip was to look at old snow surfaces and observe faceting on shaded slopes at upper elevations. The past week of clear nights has slowly weakened and faceted the snow surfaced on most slopes on the north half of the compass. Grain size remains relatively small around .5-1mm (see photo). Northerly slopes above ~10,000′ are not going to bond well with incoming snow. I dug a profile in an area with the deepest accumulations this season; the oldest snow near the ground is well-faceted, but was moist and appears to be rounding (see profile). In general, the faceted surface appears to be of more concern for the incoming storm than the weak snow on the ground. Snow coverage is pretty continuous on northerly slopes above ~10,000′ and will be a weak layer to keep an eye on with snowy weather forecasted for the second half of the week.
Northerly slopes below -10,500′ often had a soft, faceted melt-freeze crust at the surface.
See additional photos for examples of snow coverage around the CBAC forecast area. Sorry for the blurriness.
Photos:
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- Continuous snow coverage on the northerly side of Purple ridge.
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- Continuous snow coverage in northwest-facing WSC Bowl on Baldy Mountain and a bunch of tracks from the weekend.
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- Snow profile from a northerly slope to test basal weak layers and look at faceting near the surface.
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- These .5-1mm faceted grains from the snow surface on a northerly slope will bond poorly to incoming snowfall.
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- Snow coverage of north and easterly slopes near Schuylkill Peak.
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- Snow coverage of northerly slopes on Schuylkill Ridge.
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- The relatively snowy south-easterly aspects of Augusta, Mineral Point, and Purple Mountain. Mountains very near CB and to the east have far less snow on southerly aspects.
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- Mostly dry southerly slopes of Whiterock, Deer Creek, Teocalli, and Castle Peak.
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- Bare southerly slopes of Cinnamon Mountain.
