Irwin Cat Operation

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 12/20/2015
Name: Irwin Guides
Subject: Irwin Cat Operation
Aspect:
Elevation:

Avalanches:
Weather: Wx station still down. Obscured sky all day with periods of S‐5 snow. Moderate to strong winds all day, more SW in the morning and W toward the PM.
1‐3” tonight, 1‐3” tomorrow West winds 15‐25 mph.
Snowpack: 8” of new settled to 6”. Lots of minimal surface cracking in today’s new snow due to the intensity and wind. Last week’s snow is becoming more cohesive still. Likely due to warm days and now cold + settlement. Many cracks in steeper roles going full depth, especially near and below treeline (Knob steep, Cocktail), propagation is less (20‐60’) and the slab just doesn’t seem able to pull out. This will be a concern with new snow in the coming days. We are at 2.5” of H2O in the past 6 days.
Newly formed slabs are showing clean shears on crusts in sunny areas. Fast ski cuts are not effective. Heavy dolphin‐ing is the only way to penetrate the slab, and is becoming more and more difficult.

Coneys

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 12/20/2015
Name: JSJ, Donny, Level 2 Class
Subject:
Aspect: North, North East, South East, South, West
Elevation: 9,500-10,800′

Avalanches:
Weather: WEATHER: See PM Instability Form below:
Snowpack: SNOWPACK/AVALANCHE OBS: See PM Instability Form below

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West Brush Creek

CB Avalanche Center2015-16 Observations

Location: Brush Creek Area
Date of Observation: 12/20/2015
Name: Ian Havlick
Subject: West Brush Creek
Aspect: North East, East, South East, South
Elevation: 9500-12000

Avalanches: Popped a decent storm slab out on a steeper roll on NE facing avalanche path BTL. Slab was probably 60cm, and had some push to it., collapsing and propagating probably 20ft. Did not feel comfortable on steep terrain today, however, did ski small steep features nervously.
Weather: Cold air advection and orographics was surprisingly heavy and last throughout tour, showery in nature ranging from S-1 to S5. Around 6″ new in Brush overnight and today. When we gained more near treeline ridgeline, W-NW wind was a steady 15mph with a few gusts to 30. No real Solar effect on any terrain today.
Snowpack: Snowpack was surprisingly deep, but expectations may have just been that low… HS ranged 40cm to 120cm depending on wind effect and elevation. 3-5mm depth hoar first 10cm, smaller facets, with about 15-50cm new snow which was becoming slabby , especially below treeline where new snow is cohesive enough hold slab above super weak, larger grained facets. Extended column tests showed no slab firm enough for ECT to show, but was getting localized collapses around skis all day. one ECT near ridgeline after finding old hardslab. ECTPV and ECTPE SC below hardslab. Windloading confined to ridgelines where we travelled. No wind effect BTL, aside from open meadows.

IMG_2741

skier triggered BTL pocket on steep roll. Lots of hangfire 2nd skier avoided by skiing bed surface

20151219WBrushPit9500-page-001 BrushRidgeline20151220-page-001

 

Mountain Weather 12/20/15

CB Avalanche CenterWeather

Date: 12/20/2015

A small trough will bring a return to light snow showers today. Winds last night were forecasted to be fairly strong above treeline and those westerly winds will continue today. A few other very small disturbances or wiggles in the flow will keep us in unsettled weather heading toward Tuesday. Around the Tuesday time frame, the jet stream moves over Colorado while pulling in good pacific moisture. Snowfall accumulations will start ramping up with the arrival of the jet and this moisture.

Anthracites

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 12/19/2015
Name: Ian Havlick
Subject: Anthracites
Aspect: North, North East
Elevation: 10500-11500

Avalanches: observed small windslab (50′ x 10-20″ deep) on NE facing slope in extreme terrain on Whetstone, as well as similar size windslab on SE facing slope at ridgeline in Anthracites.
Weather: Overcast, with cold morning but warmed nicely. Light SW breeze at ridgetop today. Solar was present but not intense.
Snowpack: Travelled standard uptrack in Anthracites, snowpack was consistent 80-120cm deep, most notably a very widespread layer of surface hoar from last night’s cold, clear, calm night. Surface hoar 4-6mm, and present in shorter pungey trees all the way to branches. In darker timber SH was NOT present. Also evident was drifts in trees from strong NW winds last few days.

See video for test pit results. ECTX, and ECTP30 – sudden collapse at ground on 3-5mm depth hoar.

no signs of instability today aside from spooky pit results.

Anthracites20151219_graphicalpit_Havlick-page-001

Pittsburg

CB Avalanche Center2015-16 Observations

Location: Paradise Divide Area
Date of Observation: 12/19/2015
Name: Alan Bernholtz
Subject: Pittsburg
Aspect: North East
Elevation: 10,500

Avalanches: None
Weather: Partly cloudy, warm and calm
Snowpack: Shallow unconsolidated snowpack 50-70 cm. Large surface hoar and loose snow on the surface. Not much of a mudpack to speak of. No slab was observed.
Skied terrain around 40 degrees with no results. Very unconsolidated weak snow.

Ruby Range

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 12/19/2015
Name: JSJ, Donny, Level 2 Class
Subject: Ruby Range
Aspect: North, North East, East, South East
Elevation: 10,500-11,900′

Weather: Increasing clouds; Increasing temps; High of -1C / Low of -4C; Calm to Light SSW winds; Blowing snow off ridge tops ~12k SSW
Snowpack:

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Snodgrass TH

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 12/19/2015
Name: Jake, Chris, Avy 1 Prep Course
Subject: Snodgrass TH

Weather: Grey bird, No wind
Snowpack: HS 45cms, Facets capped by big SH

Snowpit Axtell Glades

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 12/19/2015
Name: Jimmy Buchanan
Subject: Snowpit Axtell Glades
Aspect: West
Elevation: 9,600 ft.

Avalanches: None.
Weather: Scattered clouds, see profile.
Snowpack: See profile.

Axtell-Dec.-19