Location: Kebler Pass Area
Date of Observation: 01/23/2019
Name: Ian Havlick

Subject: Irwin Cat Operation Meteogram Jan 1-Jan 23rd
Aspect:
Elevation: 10000-12000

Avalanches:

Weather: Irwin’s meteogram of day of month, sky cover, surface snow form, solar radiation, ridge (green) and valley (blue) temperatures, max wind gust for 24hr period, average wind, direction, 10,000ft snow height, daily snow totals, CBAC avalanche hazard. Internal product, but posted for public reference. This resource has been referenced in the CBAC Fireside Chat series and users have voiced a strong interest in being able to access this resource. Forecasters will periodically post these updated meteograms throughout the winter.

Snowpack:

Photos:

Location: Paradise Divide Area
Date of Observation: 01/22/2019
Name: Eric Murrow

Subject: BTL W and SW in snow favored local
Aspect: South West, West
Elevation: 9,000′ to 10,900′

Avalanches:

Several slides were a bit tough to tell if fresh or not because lots of crowns are still visible across the range. Certainly one fresh slide on south side of Cinnamon, D2.

Weather: Mostly clear skies down valley with clouds forming over Ruby Range and Schofield park from north flow. No snow.

Snowpack: Travelled on W and SW slopes below treeline up to 11,200′ and found HS average between 140-155cm. Stability test produced no significant results – nothing propagating. Found several small terrain features in upper 30 degrees that did not have any apparent traffic and stomped hard without collapsing or cracking. Overall the snowpack was quiet and supportive. Basal weak layers show significant signs of rounding and were generally in the 4f+ range for hardness.

Took a look at the remote triggered avalanche from Sunday on a SW at 10,800 feet. Upon inspection this slide failed on top of 1/15 suncrust, did not collapse it, involved just the drifted snow from 1/16 – 1/18.

Clear signs of drifting on to the south half of the compass near and above treeline from northerly winds.

Photos:

Location: Crested Butte Area
Date of Observation: 01/22/2019
Name: CBPSP

Subject: Phoenix bowl control routes
Aspect: North, North East
Elevation: 10,500’

Avalanches:

#1 SS-AE-R2-D2.5-O/G
#2 SS-AEy-R2-D2.5-O
#3 SS-AE-R2-D2.5-O/G
#2 was remotely triggered aprox. 600’ away over an abrupt ridge on a diff. aspect from one 2# charge.

Weather: Clear and cold with light NW winds

Snowpack: Obvious sings of windloading on lee slopes E aspects. 27” of new snow on top of 24” of very weak faceted snow that had seen minimul ski patrol traffic before the storms.

Photos:

Location: Paradise Divide Area
Date of Observation: 01/22/2019
Name: Evan Ross

Subject: Great Skiing And Quiet Snowpack
Aspect: North East
Elevation: 9,000-11,300ft

Avalanches:

Few small, loose snow like avalanches out there. No new slabs observed from the last 24hr with a good views of the upper OBJ and Slate basins.

Weather: Partly cloudy, light winds, cold temps. Didn’t observe any blowing snow and had good views of the high peaks. Doesn’t mean snow was not drifting on the peaks and not visible form a distance.

Snowpack: This snowpack is definitely making, or has made the transition out of the classic continental snowpack that exits in other areas around Crested Butte. Did not bother digging down to the middle of the snowpack to observe the old NSF layer of concern. That rounding NSF layer of concern was documented form this same area in this observation on January 12th, and in Washington Gulch on January 15th. The potentially buried SH was not observed and wether or not the SH was there, I definitely didn’t dig down deep enough to answer that question. No sings of instability observed. Skinned and skied on slopes in the upper 30 degrees. Some of which have avalanched a couple times this year and some that haven’t.

Wind-loading from last night or yesterday could not be seen. The snow looked to have fallen as the wind eased overnight and covered up any previous wind-loading evidence at ridgeline. Cornices remain smaller then normal for the time of year at ridgeline and recent wind texture showed that these cornices were being slightly eroded overnight vs loading these NE slopes.

Photos:

Location: Brush Creek Area
Date of Observation: 01/22/2019
Name: Ian Havlick

Subject: Whetstone and Double Top Avalanches
Aspect: North East, East, South East, West, North West
Elevation: 9-12,000ft

Avalanches:

Large to very large avalanches observed on Whetstone (E-SE ATL) fresh overnight (and large sympathetic slide in NE bowl). Also unknown age of the Doubletop avalanches but looked fresh bedsurfaces with binos. W-NW facing NTL terrain. Crown depths look 4-6 feet deep, failing on persistent weak layers and gauging to near ground in places.

Weather: Scattered clouds, light NW winds. 4-8″ new snow overnight and up to 70mph westerly winds overnight.

Snowpack:
Photos:

Location: Kebler Pass Area
Date of Observation: 01/21/2019
Name: Irwin Guides

Subject: Irwin Cat Ski Obs
Aspect:
Elevation:

Avalanches:

Above avalanches were both on steep, convexities, with out much skier traffic or previous work. Deepest part of crown in FOS avalanche was 1m+. Neither slide gouged into older snow in the
tracks, debris was 1m deep.
Castle Valley Left SS-AB-R1-D2-O FC-11/22 (40cm x 10m x 200m) Arblast pulled up into steep rocky Convexity,
narrow path not digging in.
Field of Screams SS-AB-R2-D2-O FC-11/22 (40cm x 20m x 130m)

Weather: FEW to OVC by 9:30 and snowing by 11a. Strong winds with period of S3 around noon back to S1/S2 for remainder of the day.

Snowpack: Stiff and smooth in UUWW with no cracking or signs of instabilities other than with
explosives. Minimal ski pen. Small grain surface hoar observed at the study plot this am before latest round of snow.

Photos:

Location: Crested Butte Area
Date of Observation: 01/21/2019
Name: Eric Murrow and Zach Kinler

Subject: Cruising around the CB area
Aspect: North East, East
Elevation: 9,400′-11,145

Avalanches:

In a quick trip out to Brush Creek trailhead, we observed D1-D2 avalanches on pretty much every steep (35 deg+), unsupported, Easterly slope above and below ditch trail. These failed near the ground of this very weak and shallow snowpack during our last loading event.

Along Gothic Road, again, multiple D1-D2 avalanches on steep, East aspects below the road. Similar to Brush Creek, these ran at the bottom of the snowpack on a crust sitting on top of faceted snow 15cm from ground.

Weather: Cloudy skies, light-moderate SW winds below tree line with occasional gusting, snow showers starting @ 12:00 with 2″-3″ accumulations during the afternoon tour. Temps in the mid 20’s.

Snowpack: Toured Northeast and East slopes below tree line with HS ~120 cm on NE and ~100cm on East.

A crown profile from a recent D2 avalanche on NE @ 10,200′ that likely ran towards the end of the most recent loading on 1/18, revealed the crown was an average of 45 cm and ran on the upper most of 3 SH layers that were observed in this location.

The snowpack was talking to us very little today with non-propagating long column results and no cracking or collapsing, however consistent slab over weak snow was felt with ski poles, SH layers were clearly visible in pit walls and lots of recent avalanche activity kept terrain choices conservative.
Photos:

Location: Crested Butte Area
Date of Observation: 01/21/2019
Name: ADB

Subject: Anthracite Mesa-Coneys
Aspect: North East, East
Elevation: BTL

Avalanches:

An east facing slope near the neighborhood and parking area. SS-N-R1-D1 likely happened 48 hours ago during the last big natural cycle.

Weather: Tour started with obstructed skies and transition to obscured skies with light winds around 1030AM. Snowfall rates were S1 and S2. Winds were mostly light with one moderate gust. Winds didn’t transport snow onto the lee slopes.

Snowpack: Open areas in valley bottom before snowfall appeared to have a fresh layer of surface hoar (<1 cm ocular estimate).
We stayed on main beaten in skin track: no cracking, collapsing, or whumping.
Snow was very supportive and had a Sierra Nevada creaminess.
Photos:

Location: Paradise Divide Area
Date of Observation: 01/20/2019
Name: Eric Murrow

Subject: Quick below treeline check on SE up Wa Gulch
Aspect: South East, South
Elevation: 9,500 to 10,400

Avalanches:

Avalanche in Coon Basin on Mt. Emmons that a friend believed to not be there on Saturday, but noticed Sunday morning. East aspect R2D2 – crown appeared to be maybe 4ish feet deep but was very narrow contained between to shallow, pungy ribs.

Weather: Comfortable air temps with calm winds below treeline. At 430 looking back towards Treasury could see healthy flagging off of peak.

Snowpack: Poked a couple of holes on SE slopes to check on PSa problem BTL and found hard ECTP results in two locations, one was shallow at 94 cm and the other at a drifted location with 143cm. Both locations failed around the same crust level mid-pack but the shallower location failed below a crust on 1.5mm facets and the drifted location failed a the crust on 1mm facets. The deeper site had the same 1.5mm facets below the suspect crust but failed above it. Both locations had a very similar structure with the key difference that the shallow location just barely had 4f slab sandwiched in upper layers whereas the deeper location definitively had slab structure above the failure location. Was not able to get a collapse by jumping around at both locations.

Photos:

Location: Paradise Divide Area
Date of Observation: 01/20/2019
Name: Via email to CBAC

Subject: Remote skier triggered SW above Pittsburg
Aspect: South West
Elevation: 10,600′

Avalanches:

remote triggered from about 30 feet away. Windloaded roll over. ssw face. 10,600, super bulgey crown, 130 cm at the tallest, 80 cm most of it.

Weather:

Snowpack:

Photos: