BC Zone Observation Report
Thursday, January 2, 2020 at 12:00 AM
Vail & Summit County
Details
Date:
2020/01/02
Observer:
Kreston Rohrig
Organization:
Forecaster, CAIC
Location
BC Zone:
Vail & Summit County
Area Description:
Dug at the top of Marvin's, descended Tele-line
Weather
Ridgeline Wind Speed:
Calm
Ridgeline Wind Direction:
W
Wind Loading:
None
Temperature:
20 F
Sky Cover:
Broken
Depth of New Snow:
30 cm
Depth of Total Snow:
145 cm
Most Significant Precip Rate:
S-1 - < 1 cm/hr
Weather Description:
Broken skies with continued orographic showers. Surprisingly calm at ridgeline with no wind-transport.
Snowpack
Snowpack Description:
I thought that the snowpack would have been deeper and stronger but this was not the case. Depth was 145cm with the upper 30cm added in this last storm. The new snow was super light and low density. Below the new snow the same 30cm of old facets that used to be the old snow surface are now buried. Below the facets, the mid-pack slab (50cm thick) has lost a lot of strength. This layer is barely hanging on to 4 finger hardness and sits above super weak fist hard facets and depth hoar at the bottom. This is the same bad set up I've seen in many areas near and below treeline. The new storm snow was very reactive in stability tests and propagated a fracture in an ECT with only three taps.
Avalanches
Avalanche Description:
There was a fresh rider triggered storm-slab avalanche just below the ridge in Marvin's. It only took the new snow but did run down to the bottom of the path.
Date
Location/Path
#
Elev
Asp
Type
Trig
SizeR
SizeD
2020/01/02
†
Vail Chutes
1
TL
E
SS
AR / u
R2
D2
Date:
2020/01/02 (Estimated)
Observer:
Kreston Rohrig
Organization:
Forecaster, CAIC
Landmark:
Vail Chutes
Media
Images
