Location: Cement Creek Area Date of Observation: 01/30/2018 Name: Eric Murrow
Subject: Cement mountain avalanche observation Aspect: North Elevation: 11,500’
Avalanches:
While taking the dog for his afternoon romp, I noticed an avalanche in upper horse basin on cement mountain. I can’t quite remember when the last day I was up here but I believe it was Saturday 1/27 ( not real confident on this but my best guess). Sorry for the horrible image, but with naked eye I could ID this from valley floor. This is a north aspect @ treeline. Good example of terrain you won’t see me skiing anytime soon; near treeline, shaded aspect, and obvious wind affected! I would say it’s a D1.5 or maybe D2.
Location: Crested Butte Area Date of Observation: 01/30/2018 Name: Evan Ross
Subject: Facet Sluffing Aspect: North East Elevation: 9,500-11,145
Snowpack: Full depth facet sluffing on slope angles near 40 degrees. Didn’t get an HS on the upper elevation slopes, but even those that didn’t appear to have avalanched this year were still weak and sluffing to the ground. In the more open terrain, ski pen rode up higher in the snowpack on wind-loaded or cross-loaded terrain features with a more developed mid-pack. No signs to instability while skiing on these terrain features.
Location: Crested Butte Area Date of Observation: 01/29/2018 Name: Ben Pritchett & Eric Murrow
Subject: Persistent Slab hunting on Mt. Emmons Aspect: North, North East, East, South East Elevation: 9,000-11,000′
Avalanches:Â triggered several small loose facet sloughs on steep slopes below 10,500′ on north through east aspects. Weather: warm day, no signs of wind Snowpack: Went to find the threshold for where persistent slabs remain a problem. We know that our eastern end of our zone is so weak that below treeline in the upper brush creeks and cement creek areas, the generally too weak to propagate a crack. We also know that around Pittsburg persistent slab structures and still exist as evidenced by last Thursday’s remote trigger, and two known skier trigger slides in the Purple Palace area today (Monday January 29th). So we went to the in-between zone, closer to town, right on the margin of the snow belt.
Below 10,000′, we found rotten, faceted, trap door conditions on north through east slopes. Facet sloughing on slopes ~40+ slopes. Crusted on southeast aspects.
10-11,000′ seems to be the sweet spot for the lower margin for remnant persistent slab concerns. The slabs are losing strength, but still propagating in ECT’s and PST at around 10,000′. Above 10,000′, there’s no question that a hazard remains if you’re on a steep slope with wind consolidation from old drifting or steep sun-settled slopes just south of east. At 10,900′ on a slope angle in the high 20’s, we triggered a 40′ wide collapse as we neared an east-southeast facing ridgeline, complete with shooting cracks.
Location: Paradise Divide Area Date of Observation: 01/29/2018 Name: Mark Robbins
Subject: Beyond Pittsburg Aspect: North, North East
Avalanches:
We skier triggered this R2D1 on a NE aspect at around 10,800’ today. I thought we were making the right call by heading to terrain that had already slid in the last storm cycle, but though there isn’t much new snow, the new slab hasn’t bonded to the bed surface and had just enough energy to potentially take you off your feet and into hazards. So I underestimated the hazard dropping into the zone, but once we were committed we recognized the danger and negotiated the terrain as best we could. We had stopped just above this convexity, and my partner (unintentionally) triggered it with his first turn and was able to quickly cut back to the safety zone from which I shot the second photo before the failure further propagated. It ran slowly about 250 ft(?) into trees below.
Hard to say how consequential it would have been if he’d been caught in it – definitely not enough to get buried, probably enough to take you off your feet, possibly enough to break bones hitting trees, definitely enough to scare the shit out of you – so both of us feel fortunate that we were already on guard and ready to make the quick move to safety. Avalanche problem was on the smaller side due to the thin snowpack where it had already slid, but magnified by the consequence of the terrain with trees below and continued exposure as we navigated our way out of the zone.
Feeling sheepish that I pushed to ski this zone, incorrectly assessing the dangers versus benefits of skiing the slide path. But we learn way more when things go wrong – after all we never really know if things went right in the backcountry, the danger of the positive feedback loop. Thanks to my partner shif for an educative and ultimately safe day, and to other tourers who also successfully picked their way through the tender zone.
Location: Paradise Divide Area Date of Observation: 01/29/2018
Subject: Touchy Aspect: North, North East Elevation: atl, tl, btl
Avalanches:
Plenty of pockets of old avalanches on anything due north in the trees and steeper than 30 degrees. Once we dipped below treeline on descent there was plenty of cracking in top 10-14 inches on N and NE aspects on steeper slopes. Got a pocket to release, 14 inches deep, above a skier while skiing a due north gully that was no steeper than 30 degrees, maybe 32 degrees at the point of release. Top 14 inches moving slowly for about 75 feet and then crept to a stop. Burial not likely but would have sucked on steeper, more sustained pitch. Super slick bed surface evident as we continued lower in elevation.
Weather: April warm, not a hint of wind Snowpack: 18 inches deep and facets at the start of hike getting progressively deeper the higher we climbed reaching a depth of 5 feet, give or take, above treeline with stiff and thick midpack sitting on good old facets. Eight inches of ski pen as we got higher and on the descent off of ridge top.
Location: Crested Butte Area Date of Observation: 01/28/2018 Name: Casey Graham, Chris Martin
Subject: Thin Wind Slab and Variable PS structure Aspect: North, East, South Elevation: 9,200-10,200
Avalanches: Weather: 0deg C for most of the day leading to warming of the surface snow on S aspects, but little change on the Northerlies. Light winds BTL on Snodgrass but blowing snow from NW winds observed in the alpine on the summit ridge of Gothic. Mod. winds on top of Coneys moving some snow down the bowl potentially building the WS near the ridge. Added some wind texture to the skiers left lines and on some isolated cross loaded looking features. Few-Sct clouds all day. Snowpack: Coney’s: Consistent PS structure observed from the valley floor and up through the trees. HS was around 1m on average. Thin (15cm) WS developed at Ridgeline on the lee – breakable. Multiple CTNs in open meadows near 9700ft and 1 CTH with an SC. The slab in this zone ultimately seems more and more stubborn by the day, but if it does fracture, wide propagation in the terrain seems likely. Lots of tracks pounding the “Nose” and Convex Corner area over convexities with no activity observed.
Snodgrass: Toured from Washington gulch to the saddle between SG and Gothic. Southerly aspects had 8-10cm of soft snow with some surface faceting in the morning on top of 20-40cm of crust/facet layers to the ground. Hot Pow conditions by 1130 on these aspects. N-NE aspects revealed a finicky PS in open terrain at 10,200′ with thickness ranging from 30-50cm of 4F over the garbage V layer which was pretty uniform at 20-25cm. 205-35cm of the light and fluffy on top. CT’s were inconsistent ranging from a few CT12’s with Q1-Q2 SC character to CT30 Q3 RP and an ECTX. HS was 85-95cm with more reactive tests in the former. Ultimately with some digging and probing, the slab was pretty inconsistent and seemed to be eroding across much of the terrain on these aspects.
No big red flags on the day and pretty great ski conditions overall.
Location: Crested Butte Area Date of Observation: 01/28/2018 Name: Finn smith
Subject: Previous slide Aspect: North East Elevation: Around 11300
Avalanches:
No new slides that I’m aware of. The one I’m reporting was recent in the past week or so and was triggered from the cornice above that broke from a skier.
Weather: Sunny temp. around 20-30 degrees F. Snowpack: Shallow with ice at the bottom and all facets.
Location: Crested Butte Area Date of Observation: 01/28/2018 Name: Ian HAVLICK
Subject: Elkton Aspect: East, South East, South, South West, West Elevation: 9200-10500
Avalanches:
Did observe one relatively recent D2 avalanche in Avy 1 glades confined to steeper, shadier side of convex slope. E facing, BTL.
Weather: Partly cloudy, some high peaks had lingering stratus. Moderate NW winds at all elevations. Temps were generally cold but very strong solar radiation warmed day. Snowpack: Biggest take away from field day was sneaky and steady W-NW winds at all elevations drifting skin track quickly, and changing snow surfaces to moderate ripple and wind crusts/slabs. No signs of instability while traveling. Generally supportable with ski pen 10-20cm.
Location: Kebler Pass Area Date of Observation: 01/27/2018 Name: Jeff
Subject: Small Natural Windslab Aspect: North Elevation: 9,400-12,390
Avalanches:
1 X D1 natural windslab ~100m below ridgeline ~12K, East, in steep terrain under cliffs.
Weather: Temps stayed brisk all day
Winds: light to Mod BTL & NTL. Strong at ridgetop w/ plumes
Sky: Mostly clear with increasing clouds through the day Snowpack: HS 30-100cm varying from 9,800 in dense conifer forest to limit of treeline @ 11,500
late morning snowpack was moist on 25* SE slope @ 9,950, dry on Northerly slopes all day.
Ski pen to ground in shallow areas around obstacles, but riding higher (15-30cm ski pen) where midpack was present. Intermittent dense & deep windslab NTL with 10-30cm of F hard snow on top 2-3 small collapses and cracks on skin track on lap 1
At 10,750, N, open slope over jagged talus:
2 large collapses on skin track on lap 2 within 10m of each other.
1st shook trees ~25m away, 2nd created cracks 75m away & echelon cracks throughout the avg 25* slope.
Frequently feel when you’re moving off the slab and into the depthhoar and easier to trigger the PWL. Ironically, the 2 big collapses boomed out on a section of firm skin track adjacent to many soft, weaker areas
Location: Kebler Pass Area Date of Observation: 01/27/2018 Name: Cam
Subject: Southerlies Aspect: South East, South, South West Elevation: 11,000-12,400 ft
Avalanches:
Observed one avalanche on an East face in Elk Basin beneath the old mining road. 50 ft wide ran about 150 ft. Too far away to tell anything else, but it appeared fairly fresh. Several recent point releases were visible on steep East facing terrain.
Weather: -14F leaving the car 9,000 ft at 0800 hrs.
Warmed up as we climbed and the day went on. Around 25 degrees F by the afternoon.
20-30 mph winds from the W above treeline throughout the morning. Not a cloud in the sky. Snowpack: HS generally between 40 and 70 cm below ridgetops. Facets at the ground, a solid crust 20-30cms from the ground, and unconsolidated soft snow on top.
Shallow windslabs in cross-loaded terrain acted like they wanted to move, but there wasn’t enough energy there. The 2-3 inches from Friday was sitting happily in areas below treeline and in basins. On the ridges and up high it was scoured off.
Skied southerlies up to 35 degrees without any signs of instability. Direct south faces were thin but supportive.
Ski pen- 10 cm Boot pen- deep
