Little change on westerly aspects NTL/BTL

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 12/07/2016
Name: Evan Ross
Subject: Little change on westerly aspects NTL/BTL
Aspect: South West, West
Elevation: 10,000-11,400

Avalanches:
Weather: Broken skies, moderate to strong gusty SW winds with moderate snow transport. Trace accumulation mostly in the Am hours.
Snowpack: Little change from Zach’s observation in the same area on 12/7. 5″ new snow overnight in protected areas, was only around 2-3″ on most open slopes. That 2-3″ didn’t change anything in these areas and wasn’t cracking or showing much for signs of instability. A few very soft, very small, phone book slabs around at best. This new snow was sitting on wind-board and crusts buried on 11/7.

The new snow in this observed terrain was mostly being blown onto NE-SE slopes where we didn’t travel.

Washington Gulch

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 12/07/2016
Name: Jeff Banks
Subject: Washington Gulch
Aspect: North East, East
Elevation: 9600-10,300

Avalanches:
Weather: OVC, L/M NW winds funneling down washington gulch S-1 from 12:00 onwards
Snowpack: SNOWPACK: BTL ENE. No signs of instability
HS40-5Ocm,
skipen 10-20cm
ftpen ground
Top~10cm loose facets/intermittent wind affected, often 4F/1F in open main valley
~25-30cm weak faceting mid pack but just supportive to 110mm skis
Bottom ~10cm large 2-4mmfacets/some polycrystals, almost cohesive enough to make a snowball

Small windslab

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 12/07/2016
Name: Zach Guy
Subject: Small windslab
Aspect: North, North East, South East
Elevation: 9,500 – 11,300 ft

Avalanches: On a NE aspect NTL, we skier triggered a small soft slab, ~8″ thick, that ran about 1,000 feet and was D1.5 in size as it entrained a fair amount of snow. SS-AS-R1-D1.5-I. No other avalanches observed, but alpine views were obscured by clouds.
Weather: COLD. Calm to light westerly winds where we were with no snow transport, but I could see plumes of blowing snow off high peaks from the northwest. Periods of S-1, and broken skies.
Snowpack: See profiles. 5″ of new snow below treeline, drifts up to 8-10″ near treeline. Not much wind effect in this area. Below treeline lacks slab cohesion for avalanche concerns; some minor cracking in the new snow but no other signs of instability or propagating test results. Small grained facet layers could be problematic with future storms. Same for southeast aspects near treeline. Some minor cracking in the new snow, but no load right now on a concerning facet/crust layer. On a due north, near treeline slope ~11,300 ft, we found the unnerving 11/18 interface (3-4 mm, fist hard depth hoar) below a 75 cm cohesive slab. This layer appeared to be discontinuous due to patchy coverage and/or ground surface roughness. Non propagating ECT results but sudden collapse CT results. No signs of instability while jumping hard above the slope of concern, but we chose to avoid that slope and steer towards a NE pitch that didn’t hold the depth hoar layer.

N aspect NTL
SE aspect NTL
NE aspect BTL
Minor cracking under foot at the new snow interface, both on shaded aspects (on NSF) and sunny aspects (MFcr)

Minor cracking under foot at the new snow interface, both on shaded aspects (on NSF) and sunny aspects (MFcr)

Debris pile from a small, skier triggered slab avalanche.

Debris pile from a small, skier triggered slab avalanche.

Gothic 7 a.m. report

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 12/07/2016
Name: billy barr
Subject: Gothic 7 a.m. report
Aspect:
Elevation: BTL

Avalanches:
Weather: The 24 hour total is 6½” new snow of 0.39″ of which 4½” and 0.29″came after dark. Snow started late afternoon and went moderately until 10 p.m. and then wind started, moderate but steady overnight with just light snow after that. Currently a little bit of clearing as temp. has dropped to the low of 5F. There is 17″ of snow on the ground and wind has turned light, though there was some drifting during the night. billy
Snowpack:

Rustler’s Gulch obs

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 12/04/2016
Name: Peter Innes
Subject: Rustler’s Gulch obs
Aspect: South, South West
Elevation: 11,000′

Avalanches:
Weather: Sunny, temps just below freezing, no wind.
Snowpack: Widespread and repeated whoomphing on an open, S/SW facing, 30*-35* slope near treeline.

Wind crusts and slabs

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 12/06/2016
Name: Zach Guy and Evan Ross
Subject: Wind crusts and slabs
Aspect: East, West
Elevation: Near treeline

Avalanches: None
Weather: S-1 began around 11:30. Trace accumulation through the day. Moderate SW winds. Overcast skies.
Snowpack: West aspects NTL surface is a mix of P-hard wind crusts (~1-2″ thick, supportive on skis), and wind textured DF’s/small grained facets. On an east aspect NTL, there were 4″ fresh drifts, P-hard, with minor cracking. No other signs of instability.

Snodgrass Tours

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 12/03/2016
Name:
Subject: Snodgrass Tours
Aspect: North, North East
Elevation: 11000′

Avalanches: No signs of instability observed.
Weather:
Snowpack: Toured north side of Snodgrass on Fri (12/2) and Sat (12/3) to check out snowpack prior to this weeks’ pending storm. HS varied from ~25cm up to ~65cm in protected areas on N / NE facing slopes.

Dug test pit at top of 1st Bowl on a protected 30* slope at 11K’ on 12/2. Structure was as follows:
HS: 65cm: 4cm of new snow; over ~41cm of 4F- .5mm rounded grains from late Nov storms; over 20 cm of F 1 – 1.5mm facets. ECTN 14, Q3 @ 20 cm facet layer.

Poor structure is there and found the facet layer down to ~10k’ on N facing slopes, but slab from late Nov storm showed limited consolidation / propagating potential except in the most wind-effected areas.

Weak, unreactive snowpack on westerly aspects.

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 12/05/2016
Name: Zach Guy
Subject: Weak, unreactive snowpack on westerly aspects.
Aspect: South West, West
Elevation: 10,000 – 11,400 ft.

Avalanches: None
Weather: Broken skies, strong SW winds with moderate snow transport. Brief pulses of S-1 with trace accumulation
Snowpack: On W and SW aspects N/BTL, the snowpack is generally too incohesive or shallow for avalanche concerns. Slabs from last week’s storm are faceting away. Non-propagating results in ECT’s, no results from explosive testing or ski cuts. 1 cm melt-freeze crust on SW aspects, with .5 mm facets below. West aspects remained dry yesterday, and the surface is small grained facets or windpacked grains.

DSCN1140

Mt. Baldy Avalanches

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 12/03/2016
Name: Chris Miller
Subject: Mt. Baldy Avalanches
Aspect: North
Elevation: ATL

Avalanches: See photos, Northerly aspects of Mt. Baldy
Weather:
Snowpack:

bros-1-of-1-7-01
bros-1-of-1-6-01

Shallow Windslabs above treeline

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 12/04/2016
Name: Sam Lesnikoski
Subject: Shallow Windslabs above treeline
Aspect: North, North East, East
Elevation:

Avalanches: Two older natural windslabs off of purple ridge above treeline. Triggered two windslabs on east facing aspects from skin track on ridge by stomping on ridgeline convexities, ran aprox. 50 ft. Triggered longer running windslab by ski cut from highpoint of ridge on more north east facing aspect. Ran approx. 500ft from ridgetop to bench. Quickly dissipated into shallow sluff.
Weather: Calm, sunny. Intermittent light breeze. Cloud cover and breeze increasing by afternoon.
Snowpack: Uniform below treeline, ski pen 6-8 inches boot pen 16-20 inches. Isolated shallow/soft windslabs above treeline.