Location: Paradise Divide Area
Date of Observation: 03/21/2020
Name: Eric Murrow
Subject: Elkton area obs
Aspect: North East, East, South East, South, South West, West
Elevation: 9400′ – 11700′

Avalanches:Visbility was obscured for much of the day but had a few glimpses into near and above treeline terrain and observed just one avalanche that I would guess failed maybe on Friday on a drifted near treeline slope the faces northeast. Looked to be about D1.5 on a very drifty feature below a cornice.

Weather: Mostly cloudy skies after about 10am with on and off snow showers. The sun was often visible through the cloud cover and green-housing was felt multiple times during the day. New snow accumulation during the day through 330pm was about 2 inches. A brief period of sunshine early in the morning shortly after sunrise was enough to moisten the snow surface on slopes with any exposure to the sun including northeast.

Snowpack: Poked a number of holes on northeast, east, southeast, south, southwest, and west-facing slopes between 10,000 and 11,700 feet. Settled storm snow was generally in the 20 to 24 inch range. At a location with 22″ of storm snow I measured 1.9″SWE at noon.

On slopes that faced east through south through west, I found the storm snow was bonding much better than the day prior. CT’s, ECT’s, and hasty hand shears were not able to produce any results on top of the crust sitting below the storm snow. I made several attempts to identify faceted grains but couldn’t. The slab appears to be bonding reasonably well. No cracking was observed.  Southeast through south through west slopes had crusts strong enough carry the current new burden. East facing slopes around 11,000′ had a thinner crust but there were frozen ice columns beneath for several inches. East and southeast slopes had a few inches of moist snow from this morning’s sun near the surface. South and west slopes had a soft crust buried beneath four or five inches of dry snow that formed during yesterday’s brief sunshine in the afternoon.

Slopes that tilted more north of east were a different story. There is a soft thin crust at the new/old interface with a very thin layer of facets immediately above. Test results were ECTN 12,13 at the new/old interface on this slope. Slab hardness is mostly fist and 4finger with a small amount of 1finger right above the new/old interface. Slopes with this structure may present the chance for triggered avalanched longer than slopes on the south half of the compass. The snow beneath the crust was also slightly faceted but most of this snow was graupel-ly precip. This layer may be worth watching with more loading.

Photos:

Location: Kebler Pass Area
Date of Observation: 03/21/2020
Name: Evan Ross
Subject: Sluffs And A Small Slab
Aspect: North, South East, North West
Elevation: 9,000-12,400

Avalanches: Small dry sluffs in the alpine. One fresh, small D1.5 slab, on a ENE facing slope, at 11,800ft. Unknown trigger on the slab, maybe people hiking above.

Weather: Clouds increased in the morning becoming overcast to obscured with S-1 snow. Light filtered through thin clouds at times improving visibility and creating some green housing. Calm wind.

Snowpack: No signs to instability were encountered. Similar to yesterday, many small dry sluffs have run in the alpine but those are not further triggering storm slabs. There has been very little wind-loading in the alpine over the last couple days. Wind-loading during the peak winds last Thursday, has been covered up by the more recent snow falling with little to no wind. While observations pointed to more of a sluffing avalanche problem, we still considered the possibility of triggering a slab avalanche on some steep terrain features or unsupported slopes.

A test profile on a northerly facing slope at 11,900ft. Had an HS of 250cm. A thick layer of grauple was down 65cm and a couple storm instabilities were found in the upper snowpack. No significant test results.

Location: Paradise Divide Area
Date of Observation: 03/21/2020
Name: Eric Murrow
Subject: Storm snow
Aspect: North, North East, East, South East
Elevation: 8900′ – 10400′

Avalanches: During a brief period of clearing observed numerous fresh loose avalanches on steep terrain at all elevation on north, east, south, and southwest aspects. Also observed a D1.5 Storm Slab on ENE aspect of Schuylkill Ridge, that look to have failed yesterday.

Weather: Mostly cloudy skies with on and off snow showers. New snow accumulations during the day were less than 2 inches. During the afternoon skies began to slightly clear with short periods of sunlight.

Snowpack: Storm total at 10400 feet was right about 20″ with 1.7″SWE. Snow from the previous day was noticeably denser. Ski pen was several inches above the new/old interface. Quick tests on the storm snow showed marginal bonding with old surfaces (crusts and dry snow). Overlying slab remained fairly soft, but on the steepest features was still able to shoot cracks up to 20 feet. At the end of the day sun and warming temps began to moisten the snow surface on all aspects but due north below about 10,000 feet and rapidly settle the snow that was hit by direct sun.

Photos:

Location: Paradise Divide Area
Date of Observation: 03/20/2020
Name: Joey Carpenter
Subject: Skook
Aspect: North East
Elevation: 9-11.4k

Avalanches:
R1D1 skier trigger along small convexity at 11.1k approx 18 inches deep. Ran more like loose dry than slab. Broke in frown, not lateral slab release.

R1.5D1.5 on larger convexity just below approx 10.8k that broke more like 3 smaller slabs as skier cut across the roll. Confined to storm snow. 18” deep and 200ft wide. Not enough to bury but definitely enough to carry and rake an unsuspecting skier through terrain features… Debris ran around 400 vert.

Weather: On and off snowfall throughout the morning. Approximately 2” accumulation. Brief periods of sun rapidly altered low elevation snow surfaces but everything above 10k stayed cold on aspect we traveled.

Snowpack: Storm settled to ~18” from yesterday. Lower elevations had moistened crust beneath storm snow.

Photos:

Location: Paradise Divide Area
Date of Observation: 03/20/2020
Name: MR

Subject: baxter basin avalanches

Avalanches:
first two photos is of sluffs that ran on the SE face of Cascade, the longest of which ran estimated 600-800 vertical feet. Ran around 11 am today.

third photo is north face of schuykill sub peak above the eastern side of camo glades. Estimated crown width 300-400 feet, running 100 feet or so, maybe 12 inch crown, guessing it ran either end of day yesterday or sometime this morning.

Last photo is SSW facing, wet loose, just reaching our sled track from the morning. Guessing it ran 800-1000 vertical feet, sometime early afternoon today.

Weather: intermittent snow all day, staying surprisingly cold in the trees. sun peaking out occasionally and warming the air and non-sheltered snow rapidly.

Snowpack:

Photos:

Location: Crested Butte Area
Date of Observation: 03/20/2020
Subject: Gothic Obs
Aspect: North East, East
Elevation: 9500-10500

Avalanches:Skier triggered a R1D1 storm on a 37 degree rollover. Propagated about 150ft wide, but only ran 50ft downhill

Weather: On and off snow all morning. Sometimes heavy

Snowpack: 14” from the storm when we left up to 17” when we got back

Photos:

Location: Kebler Pass Area
Date of Observation: 03/19/2020
Name: Ben Pritchett
Subject: Red Lady Ob

Avalanches: On slopes steeper than about 35 degrees it was easy to trigger Storm Slab avalanches underfoot and remotely down-slope and on adjacent features 200-300 feet away. Slabs were slow and pushy, generally between 1-2 feet deep, but gather a pretty good head of steam given the dense new snow. Given the terrain we were testing, most avalanche remained on the large side of D1, but where small slides ran into steeper connected terrain below, the slides easily grew to D2’s. Where the old snow surface was crusted, triggering was easy, failing on small facets above the crust. These facets were difficult to isolate on a card and identify given the sticky snow, but no question the sunny slopes had facets failing below the storm snow. On shadier slopes, the storm snow was stubborn to trigger. It was difficult to trigger slabs on steep northeasterly-facing slopes with soft old-snow surfaces, but once avalanches initiated on crusted slopes impacted the shady slopes, they would break too.

Weather: Ridgeline Wind Speed: 20-30 mph
Ridgeline Wind Direction: W
Wind Loading: Moderate
Temperature: 25 F
Sky Cover: Obscured
Depth of New Snow: 28 cm
Depth of Total Snow: 140 cm
Most Significant Precip Rate: S5 – 5 cm/hr
Weather Description: Very snowy day. Started around 3am, didn’t let up until around 6pm. Picked up over a foot of snow, with over an inch of water near Crested Butte. Snowfall reports from riders coming back from around Kebler Pass reported over 20″ new snow. Winds picked up after sunrise, and stayed strong through mid-day.

Snowpack: Snowpack Description: Thick, dense new snow fell on faceted crusts on E-S-W facing terrain. This may be a new Persistent Slab problem.

Photos:

Location: Kebler Pass Area
Date of Observation: 03/19/2020
Name: Eric Murrow
Subject: Anthracites obs
Aspect: North, North East, East, South East, South
Elevation: 9,200′ – 11,500′

Avalanches:
Observed several natural Storm Slabs prior to noon along the Kebler Pass corridor prior to TH, small, steep northerly-facing slopes. around 6 inches deep, below treeline.

Skier triggered around 5 Storm Slabs in the afternoon 12-18″ deep on north and northeast facing slopes in the Anthracites, D1’s, near treeline.
Intentionally skier triggered two Dry Loose avalanches on steep south/southeast facing slopes. D1 in size but fast-moving on the old crust. No propagation observed while running.

Observed a natural avalanche that ran through the “friendly finish” area of the Anthracites. This failed sometime in the afternoon. Could not see crown due to visibility but presumably failed in the drifted start zone above. Although debris was shallow, it was able to run to the valley floor, east facing.

Weather: Obscured skies between 1130am and 430pm out Kebler Pass corridor. Westerly winds transported some snow near ridge top, but less than I would have predicted. Wind speeds at this location generally remained below 20mph at ridgetop. Snowfall was continuous all day with rates between S1 and S3.

Snowpack: New snow accumulations at 11,300′ around 4pm were about 20″ with 1.4″SWE. The new snow was settling to some degree while it was accumulating during the day. New snow was relatively low-density with exceptional ski quality. There was an interface around 2 or 3 inches up in the new snow that was easily identifiable in hasty hand pits that I would suspect was responsible for most of the skier-triggered Storm Slabs in the area (only stuck my mitts into two crowns).

Terrain features that were being pressed or loaded by the wind started to feel top-heavy at the end of the day. Cracks up to a ski length became more common towards later in the day as the snow continued to settle.

Photos:

Location: Crested Butte Area
Date of Observation: 03/19/2020
Name: Evan Ross
Subject: Climax Storm Slabs
Aspect: North East, East
Elevation: 9,000-11,300

Weather: Calm wind with a couple strong gusts during our short stay at 11,000ft. We headed out after the peak precipitation in the morning, so S1 throughout our tour.

Snowpack: Let’s start small to large. We struggled to get out of easterly tilted slopes in this generally NE facing terrain. Where there was a crust at the old snow surface, the storm slab avalanche problem was reactive on 40+ degree terrain. 30-degree terrain would produce some cracking but wasn’t steep enough to get things moving unless the slope was unsupported. These slabs broke below skis and didn’t propagate very wide. They never pulled down from above. Initiation was at or just above the crust. More northerly facing slopes that didn’t have the crust at the old snow surface were more stubborn to trigger and didn’t run as well on the softer bed surface. HST and crown height was in the 25 to 30cm range. These avalanches were all D1 in size until reaching near treeline start zones. A couple of natural D1’s were also observed.

Getting up to the 11,000ft elevation and into steep NTL start zones, terrain avoidance was obvious given the instabilities found at lower elevations. A simple ski cut produced a wider propagating Storm Slab with a crown in the range of 30 to 40cm range. This crown didn’t propagate horizontally through the terrain, but in a steep downslope frown that was difficult to see how far across the slope it went. Debris from that avalanche were later observed 2,000ft below. This is perfect terrain for producing long-running avalanches.

We worked our way down on ribs in the terrain where you could shred pow above where the small Storm Slabs would initiate. Given the consisted and steep slope angels of this terrain features, the small slabs accumulated mass and kept running to near valley bottom. This terrain is also one of those places to find some of the worst-case avalanche problems in the CBAC FX Area. We found just that when a small Storm Slab stepped down and triggered a larger Persistent Slab failing at the ground in a shallow weak snowpack. That avalanche stepped down on the 3 rollers in the terrain it passed through. Each added mass and produced a D2.5 avalanche by the time it got close to the valley bottom. I don’t think we could have human triggered one of these deeper Persistent Slab Avalanches, and the bigger mass of an avalanche was needed to start gouging things out.

Location: Crested Butte Area
Date of Observation: 03/19/2020
Name: BA
Subject: Sluffs and Small Storm Slabs
Aspect: North, North East, East, South, South West, West
Elevation: 9,400′-11,000′

Avalanches: 3rd bowl Snodgrass – Multiple D1 storm slabs and small, slow moving dry loose triggered on NE, mostly small terrain features steeper than 35 degrees. Storm slabs were 4F/4F- and breaking on the new interface or within the storm snow. Dry loose were all within storm snow. We avoided any large terrain features that would have held potential for larger storm slabs.

Weather: Snowing all day with lots of variation in snow types and density throughout the day. Winds increased around 2pm, but not enough to transport significant amounts of snow in our sheltered areas.

Snowpack: Variable amounts of new snow and significant accumulations throughout the day, up to 30cm in places by afternoon. No signs of instability anywhere besides 3rd bowl. Skiing was excellent.