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Post storm observations from Glacier
Location Name:
Forecaster Observation - Mt. Brown, GNP
Observation date:
Wednesday, December 19, 2018 - 15:00
Is this an Avalanche Observation:
No
Observation made by:
Forecaster
Tabs
Quick Observation
The 12/18 storm snowline was ~ 4000'. At 5000' new snow depth was 8-10" with up to 15" at 7500'.
Instabilities in the storm snow were much less than expected.
The new snow was relatively dense and upside down. Cracking underfoot occurred frequently at mid and upper elevations. This failure was within the new storm snow up to 8" below the surface.
Moderate to strong SW, W, and NW winds had left a snow surface wind affected on these aspects.
New cornice growth was impressive and much too dangerous to kick. Smaller safer cornices failed with moderate ski stomping.
Snowpack, Avalanche, Weather Images:
Travel Details
Region:
Glacier National Park - McDonald Lake Area
Route Description:
Up the Mt. Brown summer hiking trail.
Snowpack Details
Snowpack and Weather Details:
Terrain
Elevation of observation:
3500-5000 ft
5000-6500 ft
Above 6500 ft
Aspect(s) of observation:
NE
E
SW
W
NW
Red Flags:
Blowing snow
Persistent Weak Layers:
Facets or Faceted Crust
Buried
New Snow in the past 24 hours:
15.00in.
Total Snow Depth:
58
More comments about the snowpack and weather:
The 12/18 storm has bonded well to the old snow layer (12/10 storm) at this location. A snowpit on an east aspect at 7500' was 58" deep. The midpack layer is strong (1F) and 23" thick. The lowest 17" was composed of facets (4F). Stability tests revealed propagation at the top of the facet layer with moderate force (ECTP 18).
Blowing Snow:
Light
Wind Speed:
Light (Twigs in motion)
Wind Direction:
Northwest
Air temperature:
Below Freezing
Snow line:
4500'
Sky Cover:
Overcast (OVC)
Avalanche Details
Avalanche Details:
Date and Time of Avalanche:
Wednesday, December 19, 2018 - 19:00
