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Level 1 Motorized Class
Location Name:
Desert Mountain
Observation date:
Sunday, January 7, 2018 - 15:00
Is this an Avalanche Observation:
No
Observation made by:
Forecaster
Location
Tabs
Quick Observation
No recent avalanches. No signs of instability where we traveled. Some rollerballs from yesterday.
Several test pits at mid and upper elevations showed persistent slab structure that became thicker but less reactive as we gained elevation. Not enough new snow or wind here to form any instabilities in the upper snowpack.
Calm winds, periods of light snow, and temperature was near freezing at the lower elevation band.
Travel Details
Region:
Flathead Range - Middle Fork Corridor
Route Description:
Up Emery Ridge to Desert Mountain summit at 6,400 ft.
Activity:
Snowmobiling
Snowpack Details
Snowpack and Weather Details:
Terrain
Elevation of observation:
3500-5000 ft
5000-6500 ft
New Snow in the past 24 hours:
2.00in.
More comments about the snowpack and weather:
2 test pits: 1) Flat slope @5100' on Emery Ridge. ~50 cm slab (F to 4F) over a 6mm rain crust (12/17 freezing rain event) over moist facets (F+, 1.5mm) on the ground. No Thanksgiving crust here. Extended column and compression tests produced sudden collapse, propagating failures under moderate force. The snow surface is a few cm's of new snow above a thin rain crust (1/6 rain crust) over lower density snow. 2) NE slope at 6400' on Desert Mountain. ~70 cm slab (F to 4F to 1F-) over the same 12/17 rain crust, over dry facets (4F, 1.0 mm), above the Thanksgiving crust (1F) which is softer and faceting away from the bottom. Extended column tests produced no results, with a non-propagating failure in the facet layer with additional loading. The surface has remained dry at this elevation; no rain crusts.
