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Avalanche Assessment Data Sheet

Archived Reports   (Opens a PDF file)

Click Here for current Temple Basin Avalanche Assessment information

Assessment Date & Time: 14/06/2017 1330hrs
Observer Name/s: GK + CB
Assessment Location: Bealey Slide, Mt Rolleston (E1480057 N5248224)   Altitude (m): 1492m
Slope Angle (xº) & Aspect (1-360º Mag.): 34º, 195º

Current Weather Conditions:  
Air Temperature (ºC): -1.2ºC
Wind Direction / Strength (1-360º Mag. / Kmph): 360º @ 3km/h
Hygrometer RH (%): 70% Rising
Uncorrected Barometer (mb): 929mb Rising

Previous Activity: Storm face deload activity bring ice blocks onto snowslope for 300m.
Current Activity: Radiation snowballing at 1700m on northern aspect of Rome Ridge.

Snow Crystal Descriptor Codes

ABCDEFGH
Fresh snow Irregular grains, mostly rounded, but often branched. Early ET Rounded, often elongated. Isometric grains. Late ET. Angular grains with flat sides or faces. Early TG. Angular grains with stepped faces; at least some hollow cups. Advanced TG. Rounded grains formed by MF metamorphism. Graupel. Ice layer, lens, or pockets.

Hardness Descriptor Codes (Hand Test)

VSSMHVHHI
Very soft - Fist Soft - Four fingers Medium hard - One finger Very hard - Pencil Hard - Knife Ice - Impenetrable

Snow Structure Data

Temp
Gradient
Surface10cm 20cm30cm40cm 50cm60cm70cm 80cm90cm100cm110cm120cm130cm
-6.7ºC -4.5ºC -2.7ºC -1.1ºC -0.7ºC -0.7ºC -0.7ºC -0.7ºC -0.7ºC          
Layer Thickness
cm
(base)
Hardness
(Hand Test)
Xtal.
Size (mm)
Xtal.
Shape
Internal
Bond
Base
Shear
Force
Density
kg/m3
Water
Equiv.
Notes
1 26 VS 0.4 A Poor Very Easy 170 44mm New snow - intact
2 3.0
(29)
VS 0.5 A Poor Very Easy 320 10mm New snow - intact
3 16.0
(45)
MH 0.4 A Poor Easy 176 28mm New snow - intact
4 2.0
(47)
MH 0.8 C Poor No Shear 348 7mm Wet snow - sugary
5 8.0
(55)
VH 0.4 B Poor No Shear 456 36mm Wet snow - sugary
6 1.0
(56)
H 1.3 F Good Easy 430 4mm Melt/freeze crust
7 7.0
(63)
H 1.2 F Good No Shear 450 32mm Melt/freeze crust
8 15.0
(78)
VH 1 B Poor No Shear 448 67mm Wet snow - some facets present, 0cm to rock
Pack Statistics
Snowpack Depth: 78.0cm
Snowpack Weight: 228kg/sq.m

Pack Analysis :
Pack is primarily isothermal. 50% of pack tested was fresh from previous 24 hours. Some frost hoar facets at base of pit against rock, but assume moisture driven & benign. A 30-40cm wind-slab noted at 1800m on a NE aspect may indicate this feature may be more widespread as new snow was driven by galeforce northwesterlies throughout storm. SW gales are now redistributing snow at higher altitudes.

Shovel Shear Test :
Top 45cm of fresh snow sheared easily on underlying historical snowpack. A MF crust in the pact at 56cm also sheared easily and this weakness may remain persistent in the pack. No wind-slab noted in this location.

Compression & Foot Pressure Tests :
Basically reaffirmed the shovel shear tests, with foot pressure test

Rutschblock Test :
Not performed - no skis.

Activity Assessment :
Warming temperatures, or high level rainfall could drive some wet snow releases to Class 1.5. Windslab (30-40cm) observed on some lee to north - west aspect slopes at 1800m about Goldney Glacier, this may remain reactive for some time and would likely create Class 2-3 events if triggered.

Current Assessment :
High Alpine (2000m+) - Moderate
Alpine (1000m - 2000m) - Moderate
Sub-Alpine (Below 1000m) - Low
 

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