Irwin Tenure

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 01/05/2017
Name: Irwin Guides
Subject: Irwin Tenure
Aspect: East, South, West
Elevation: 10,000-12,000

Avalanches: Largest: D1.5 ran off a double shot in 2D at upper rockband, 16″ tapering crown, classic wind pocket in center BW D&D ran to photog tree island. Numerous D1’s 2-4″ (Mid storm today) deep high speed sluffs.
Weather: 27″, 4.5″ SWE storm total. OVC and snowing S5 all day. Winds calmed to light with moderate gusts at ridge top , but weather station still down.
Snowpack: Study plot was almost buried this AM, big wind drift out of the South, hence our 15″ w 2.8″ SWE. We picked up another 11″ by 12:15 of ultra low density snow. Explosives had the same results as ski cuts. Nothing broke into old snow, today’s SS propagating mid storm 2-4″ down. Yesterday’s storm is wind buffed 4F-1F supportive @ 20cm down with todays new snow on top. Boot top ski pen @ Lunch. HST stake buried at lunch. 60cm boot pen in upper FarOut @1400.

Heavy snowfall

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 01/05/2017
Name: Zach Guy
Subject: Heavy snowfall
Aspect: North
Elevation: Below treeline

Avalanches: Was hoping to get views of some avalanche paths but it was snowing too dang hard to see anything. Saw one natural D1.5 storm slab on a small feature.
Weather: S2 to S5 rates. Light to moderate down-valley winds; trees visibly shaking as we gained a gladed ridgeline. Temps decreased through the day.
Snowpack: In a wind sheltered, partially gladed slope below treeline: 60 cm of fist hard, storm snow over Jan 1st near surface facet layer. Easy and moderate broken fractures in mid-storm and storm interface layers. We traveled exclusively in dense, moderate angle trees and saw no signs of instabilities other than shallow cracking.  Ski pen is knee deep. Boot pen is belly button deep. Tree well hazards were a serious concern in this non-avalanche terrain.

Gothic 1pm Obs

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 01/05/2017
Name: billy barr
Subject: Gothic 1pm Obs
Aspect:
Elevation: 9300

Avalanches: A slide right across the river from my house has reached the river just once that I can remember in the past 45 years but this morning I was out in the dark and heard it run (it runs constantly in a storm so no big deal). But it kept getting lower, and lower until I heard it drop down on to the river. Best I can tell it stopped there but the powder cloud (small one) drifted right by me. The point is- very dangerous conditions. On the other hand, when I skied to Gothic the snow had set up enough that I only occasionally would break into the snow pack.
Weather: Sorry there was nothing this morning- it was awful out here and just took too much time to do anything so by the time I was done it was too late to help (if it does at all). Note, if you ever need to check the weather here go to gothicwx.org and all the data is there.

The 24 hours ending this morning at 7 had 20″ new snow but more remarkable was 2.20″ of water- about 12% water content which followed 5% water in the early portion of the storm. So it settled it fast as the deepest snow got was 65″. The wind started at 1 p.m. yesterday and has not stopped, though seems to be letting up some the last few hours. Only 2″ new snow this morning and snowing lightly now.
Snowpack:

Irwin Tenure

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 01/04/2017
Name: Steve Banks
Subject: Irwin Tenure
Aspect: East, South East, South, South West, West
Elevation: 10,400-11,1700

Avalanches: Morning D1 avalanches reliable skier triggered within the storm snow or at the interface of old snow. Minimal propagation, running fast, dry and light. By afternoon aspects from E->W became very touchy with more propagation, stiffer snow and some surprising remote triggers, almost everything steeper than 34° was moving. Still nothing bigger than D1.5 and running within the new snow, but it’s happening….
Weather: OBS all day with heavy snow in the morning (S5) and strong winds in the afternoon. Temps near 20
Snowpack: Snow went upside down quickly. Morning study plot measurements showed 8″ of 3.5% density super fluff. Great skiing. Afternoon measurements showed 6″ additional at 12%. Heavily wind affected. Skiing became very different–stiff and harder to keep the tips up!

town avalanches

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 01/04/2017
Name: Jeff Banks
Subject: town avalanches
Aspect: North, North East
Elevation: 9,000

Avalanches: nearly all of the bench slope above nordic center and hockey rink ran in 2 separate avalanches.
2 x SS-ASr-R4-D1.5-I/O
the initial failure was ~20cm down from the surface, then stepped down to the storm snow interface on NSF & SH ~40-50cm deep. Some areas of crown were small cornices (1F) buried in der Über fluff. Some slabs failed ~5cm within the NSF. Critical slope angle for release was ~37/38*

I also triggered a D1 and the whole slope fractured and slumped with an
Artificial subaru trigger (ca. 1996, rust colored) as I “rubbed” the snow bank around the lumberyard corner and rubbin’ son is racing.

Lot’s of R4 roof-a-lanches with well aimed single snowball triggers failing within the storm snow leaving ~15cm depth on the roofs.
Weather: snowy
Snowpack: widespread cracking and propagation going ~100m & triggering avalanches

Snodgrass Avalanche

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 01/03/2017
Name: Peter Innes
Subject: Snodgrass Avalanche
Aspect: North East
Elevation: 10,700′

Avalanches: We skier triggered a soft storm slab down-ridge, just north of Snodgrass summit. I believe people call this 3rd Bowl (or maybe 2nd Bowl)?

Time: 1300
Aspect: NE
Elevation: 10,700′ (BTL)
Slope: Concave like a bowl, ranging from 38 º to 45 º at its steepest. Average angle ~40º
Size: D1.5, ran for ~150′ before losing momentum and stopping in the trees below.
Crown: 10″ deep, 30′ wide and widening to 40-50′ at flanks.
Bed surface: near surface facets

Skier was caught briefly by the slide but was carried only a dozen feet or so and not buried. This slide took us be surprise, although in hindsight it shouldn’t have given the slope angle. We skied slopes BTL up to 35º with no signs of instability; the storm slab seemed incohesive and didn’t produce results in a column test. This was certainly a wake-up call and a free lesson in decision making/terrain management. It would have been easy to stick to
Weather: Moderate snow and winds all afternoon, temps hovering around 20 degrees F for most of the day. Skies partially clearing late in the afternoon with snowfall tapering momentarily.
Snowpack: Storm totals (since Sunday) are just under 20″ in the Gothic/Snodgrass zone as of Tues night. Storm snow falling mostly on near surface facets on NE aspects but with minimal apparent instability. As noted a day prior, storm snow on S aspects NTL (shoulder of Gothic Mt) was bonding poorly to a significant crust.

IMG_0077
IMG_00771

Anthracite Storm Slabs

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 01/03/2017
Name:
Subject: Anthracite Storm Slabs
Aspect: North, North East, South
Elevation: 11200-10000

Avalanches: Intentionally triggered multiple small storm slabs. Small r1d1 in rock, from left side convexity. r2d? in Big Chute. Triggered from wind loaded pockets near top on skiers left. Debris did not break small trees but piled deep enough to bury a person in terrain trap on bottom right of big. Released small sympathetic slab on steep roll above terrain trap. Also intentional remote trigger by jumping on convexities: r1d2 on skiers right of south facing bowl across from 7th. Broke 100ft wide, ran to flats. Numerous crowns in East Bowl and Playground area. More prevalent where wind loading had occurred. Slab activity was limited to steeper terrain. 7th skied with no signs of instability.
Weather: s1/s2 off and on. Occasional gusts with some wind transport up high.
Snowpack: ~18-24″ storm snow depending on loading

Red Lady Glades

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 01/03/2017
Name: Kirk Haskell
Subject: Red Lady Glades
Aspect: South East
Elevation: 12 something

Avalanches: Small natural above tree line again lookers left going into bowl , hard to tell with visibility whether it was started by cornice drop . Otherwise no signs of instability
Weather: Snow on and off with wind gusting to 20mph
Snowpack: Fresh 6″ +

On approach Large cornice build up on the ridge of the Bowl ( Lookers left ).

Natural Avalanche Climax Chutes

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 01/03/2017
Name: Alex Banas
Subject: Natural Avalanche Climax Chutes
Aspect: North East
Elevation: Near Treeline

Avalanches: D2.5 Natural overnight in Climax. Ran to the valley floor, 300 meters from the Nordic track or so.
Weather:
Snowpack:

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Crown in Northwest Bowl

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 01/03/2017
Name: Evan Ross
Subject: Crown in Northwest Bowl
Aspect: North, North East
Elevation: 11,300 NTL

Avalanches: Fresh crown on Ohio Bowl in the Anthracites. Visibility to poor for more details.

Fresh crown on Ohio Bowl in the Anthracites.