Location: Paradise Divide Area
Date of Observation: 12/17/2018
Name:

Subject: Schuykill
Aspect: North East
Elevation: 11,400

Avalanches:

No signs of recent Avalanche activity .

Weather: Winds out of the West 5 MPH . Grey skies with light snow in afternoon.
Snowpack: 130 cm at the top . South facing slopes crusty . North facing surface hoar becoming more prevalent.

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Location: Kebler Pass Area
Date of Observation: 12/17/2018
Name: MR

Subject: sun crusts and wind slabs
Aspect: North, North East, South East, South
Elevation: 10,000-11,500

Avalanches:

no new avalanches observed

Weather: building to overcast throughout morning, warm, low winds
Snowpack: south aspect – variably breaker crust with some soft snow still lurking in the trees from 11,300 down to 11,000 or so, more stout supportive crust lower down in the open.

north aspect – HS in due north facing protected trees at 11,100 – 125cm. No signs of instability on and off the skin track and few signs of wind effect in the protected trees. Soft snow wind slab widely present in more open north facing terrain (gun barrels) through all elevations (11,400-10,700 or so?)

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Location: Kebler Pass Area
Date of Observation: 12/16/2018
Name: Irwin Cat Ski Obs

Subject: Irwin Cat Ski Obs
Aspect:
Elevation: 10,200′ to 12,000′

Avalanches:

A few dribblers out of Castle valley R and Thread. All well below D1 in size.

Weather: Clear with calm winds gusting to 8 out of the W-SW. Warm with a high of 44* @ 10,200 & 33* @
12,000′. Moderate Solar.
Snowpack: No cracking, collapsing, avalanches observed today. Hand shots continue to be
effective to ground on our terrain. The 11/22 interface in the UUWW and New world is pencil hard. Moist snow
on all but straight west facing terrain.

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Location: Crested Butte Area
Date of Observation: 12/16/2018
Name: Steve Banks

Subject: More Gothic Obs
Aspect: East, South East
Elevation: 11,000-9,600

Avalanches:

No new avalanches viewed.

Weather: Sunny, hot, not a cloud to be seen. High’s +4 C with almost no wind.
Snowpack: It’s a mixed bag out there. SE slope at 11,000 almost softened enough to not be breaker crust, but it was breaker crust. On this aspect there was wet to moist snow in the top 6 cms and a couple crust/facet interfaces in the top 12 cms. Solid 4F->1F midpack on top of a P+ 14cm MF crust at the ground (October facets that have been through MF). There was a thin layer of 1mm facets on top of this crust, as well as some lingering 3mm facets on the ground below it. ECTX though prying on the column popped a smooth shear on top of the MFC in the 1 mm facets. This could be interesting to watch. HS was 72.
On East facing aspect BTL we received 2 medium sized collapses while regrouping. Probing found widespread PS structure and HS averaging 70 cms, though minimal signs of instability. The snowpack is feeling beaten below treeline, but it is hard to ignore the structure and the continual whumphing.

Photos:

Location: Paradise Divide Area
Date of Observation: 12/16/2018
Name: Eric Murrow

Subject: Below and near treeline obs out Slate River Valley and buried SH
Aspect: North, North East, East
Elevation: 9,300′ – 11,300′

Avalanches:

One unreported slide was visible on an alpine subpeak of Peeler. Debris was buffed over in basin below but still just visible.

Weather: Beautiful day with calm winds and lots of sunshine. Air temp on northerly slope at 10,400′ -2c @1:30pm.

Snowpack: Started in valley bottom and made our way up to ridge top and performed 3 profiles along the way on N and NE slopes. This area has seen some traffic over the past few days, and we travelled/dug in the vicinity of other tracks. First off the snow surface in most places had Surface Hoar- it was largest at valley bottom and diminished in size as we climbed and disappeared shortly before gaining ridge top.
HS from valley bottom to ridge top ranged from about 70 to 100cm with drifted locations up to 125 in locations travelled – several ridge top start zones that have good drifting windward fetches presumably had much deeper HS but we did not enter these start zones. In general slab structure was still present throughout this terrain with cohesive slabs being the rule not the exception. Pungy thickets did have generally weak snow, but open slopes held to the rule of slabs. Old weak facets near the ground showed signs of rounding, but with minimal gain in hardness, in each test profile. The structure looked poor upon inspection and in hand hardness but generally failed to produce concerning stability test results.
Buried Surface Hoar(wedges) was found in each test profile location, 9500′, 10400′ and 11300′. Shovel Tilt Test made finding the layer fairly easy in the upper snowpack – it was buried down 8 to 11cm in test profiles. There is clearly no slab resting above it yet just a few inches of low-density snow but if this layer does get loaded at some point in nearish future it could cause problems on shaded aspect near and below treeline not to mention the Surface Hoar currently on the surface.

We travelled off the beaten path in a few locations probing into different spots to establish general HS heights, locations that already slid this year during Thanksgiving avi cycle were more around the 60cm range and did not have much of a slab.

See profiles below.

Photos:

Location: Crested Butte Area
Date of Observation: 12/16/2018
Name: Will Nunez

Subject: Snodgrass Steeps
Aspect: North, North East
Elevation: 9,000 10,000

Avalanches:

Ax Small facet slugging running on the P hard 2cm crust. No other instabilities where observed

Weather: Clear, Warm, Light to no wind
Snowpack: Sx HS 63in, large to small SH on shaded aspects, F to 4F mid pack w/ P hard 2cm crust to 3mm F facets to the ground. NE to N Evl 10,000 8,000f

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Location: Crested Butte Area
Date of Observation: 12/16/2018
Name: CBSP

Subject: Sock it to me ridge
Aspect: North
Elevation: 10475′

Avalanches:

AE-SS-R1-D1.5-O
10475′
N aspect
44 degree slope
35’wide X 400′

Weather:
Snowpack: Avg. HS 45cm variable snowpack mostly poor structure. Upper half of pack 2mm facets with 2-3mm facets at the ground.Isolated persistent slabs lingering in areas that did not run natural sometime during the T-day storm.

Photos:

Location: Crested Butte Area
Date of Observation: 12/16/2018
Name: Joey Carpenter

Subject: NE CB Zone Obs
Aspect: North East, South, South West, West
Elevation: 9200-12200

Avalanches:

1 small windslab that ran earlier in the week S of whiterock. SS-N-R2-D1
E face of Baldy. SS-N-R1-D1. Earlier in the week and observed from very far away.
Multiple point releases from steep SE facing terrain, also earlier in the week. A few did pick up enough snow to knock you of your feet.

Weather: Clear, calm and warm.
Snowpack: NE BTL. Too many collapses to count. All relatively small as the slab below 9.5k on NE facing terrain is eroding. Isolated terrain features did produce 20-50 foot cracks under a skiers weight. Overall in this area, at this elevation band, there is minimal slab structure and a weak, unconsolidated snowpack. However, it does seem seem possible to produce avalanches in isolated terrain features BTL where the slab is more resilient.

S, SW, W BTL spx is thin <50cm and weak. Steeper isolated features that received windloading last week did produces small whumpfs and cracks. Barely enough coverage to move through terrain below 10k. NTL collapses on isolated terrain features became more pronounced. The overall snowpack in this area averaged 60cm except on slopes steeper than 30 degrees that are predominantly S facing. The spx on these solar aspects steeper than 30 degrees was surprisingly thin and weak. Overall in the NTL elevation band the slab structure is intact but weakening. N/ATL (~12.2k) spx averaged around 75cm excluding scoured terrain. Collapsing near the ridgeline was substantial and propagating well away from our skintrack. Stability tests produced: CT12SCQ1, ECTPV14Q1 x2 on 2-3mm facets that made up the bottom 15cm of the spx. The slab resting on the facets was 1F in hardness and still very much intact. Failures were quick and clean. Newer snow near surface F hardness.

Photos:

Location: Kebler Pass Area
Date of Observation: 12/15/2018
Name: IG

Subject: Irwin Cat Ski Obs
Aspect: South West, West
Elevation: Below and near treeline terrain

Avalanches:

Lone Wolf- Shallow wind slab did not run down to the 11/22 interface

Castle Valley Left- Averaged an 80cm crown. Down to the facets near the ground. Took out the 11/22 interface.

Lone Wolf SS-AE-R1-D1.5-O FC (25cm x 15m x 175m)
Castle Valley Left SS-AE-R2-D2-G FC (80cm x 20m x 250m)

Weather: Clear, Calm winds down low with moderate gusts up high out of the west. High temps 34 @
10,200′ & 24 @ 12,000′.
Snowpack: PS structure still present in UUWW. Shallow snowpack on average less than 90cm. Single
hand shots are effective to ground in the upper upper west wall in most places.

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