Opa Hut obs Saturday AM

Location: Brush Creek Area
Date of Observation: 03/24/2018
Name: Eric Murrow

Subject: Opa Hut obs Saturday AM
Aspect: North, North East, East, South East
Elevation: Above treeline

Avalanches:

Skier triggered several very small soft slabs on SE aspect near Taylor Pass on Friday afternoon. Saturday morning with clear visibility spotted multiple large avalanches above treeline; Crystal Peak, Star Peak, Taylor Peak, Tilton and Hunter hill. All were north through east aspects

Weather: Snow totals from Friday storm at treeline were 13.5” with 1.6”SWE. Moderate winds with strong gusts Friday. Mostly clear Saturday morning.
Snowpack:

Photos:

Slides above GT race course. PC:Chris Miller

Notice small yet deep slide lower right stepping into old layers. PC: Jason Holton

Exact repeat offender of slide from early March. PC: Jason Holton

Left overs from “The Dude”

Location: Crested Butte Area
Date of Observation: 03/24/2018
Name: Benjamin H Pritchett

Subject: Left overs from “The Dude”
Aspect: East, South East, South
Elevation: All above treeline

Avalanches:

Numerous, see photos. The pattern in this set of photos is that these all failed on shallowly buried crust facet combos on East to South aspects above treeline. See the recent video from Star Pass for details on the weak layer structure.

Weather:
Snowpack:

Photos:

PM avalanche observation

Location: Brush Creek Area
Date of Observation: 03/23/2018
Name: Ben Pritchett

Subject: PM avalanche observation
Aspect: North East
Elevation: Above Treeline

Avalanches:

5x on Whetstone, 3x reported off Crystal’s North Face.

Weather: Snowed all day in the Alpine. >S5 precipitation in numerous pulses. Big pulse around 11, another around 1 (frontal passage) then numerous convective cells throughout the afternoon. Report from Star Pass included <10′ visibility all day, with only a few breaks minutes long. Strong winds transporting significant snow.
Snowpack: Wet snowpack down low. Rain saturated snowpack below treeline with a 12+ hour deluge, dropping something in excess of .5″ of liquid precip. Storm slabs in the alpine with storm totals topping 20″ near Taylor Pass. Over 2″ SWE observed at Schofield. PM winds drifted snow continuously. Taylor Pass reported no cracking in the snow. Star Pass was unable to test the new snow as visibility didn’t allow forecasters to find the cornice lip, though they did report 3 fresh avalanches.

Photos:

Baldy Drifting

Location: Paradise Divide Area
Date of Observation: 03/20/2018
Name: Ben Pritchett

Subject: Baldy Continued Drifting
Aspect: North East, East, South East
Elevation: Near and Above Treeline

Avalanches:

none observed

Weather: Steady light gusting to moderate winds from the West. High temps in the mid 20’s. High thin overcast skies.
Snowpack: Recent drifts observed 1 to 3 feet thick. Cracking was localized to areas where the drifts were 1-finger hard or stiffer. Near treeline the drifts were quiet and soft, only becoming denser / stiffer and able to crack above treeline.

Slate River storm snow

Location: Paradise Divide Area
Date of Observation: 03/19/2018
Name: Eric Murrow

Subject: Slate River storm snow
Aspect: North, North East, East
Elevation: 8900′ – 10400′

Avalanches:

Many skiers and boarders out testing steep near and below treeline terrain on northerly slopes. Few very small skier triggered loose sloughs of little consequence, and one skier triggered, D2, storm slab avalanche on Schuylkill Ridge (documented in earlier ob). Numerous very small natural loose avalanches in new snow coming out of steep rocky cliff areas near and above treeline.

Weather: Partly cloudy skies with thicker cloud cover moving over the spine of Ruby Range. Light winds at below treeline elevations, vis of above treeline terrain was in and out, but observed no snow transport.
Snowpack: New snow accumulations were 3″ at Slate river TH and increased up 5″ at 10400′. Small isolated drifts below treeline were up to 9″ deep, but no cracking was observed. Terrain that faced NW – NE had dry snow underneath new snow but NE – E had 1-3cm sun crust below new snow (faceting was apparent below the crust, and could be a problem if a significant load is deposited in near future). Also of note – found graupel layer in drifted areas from Friday’s storm(3/16), CT’s produced moderate results on the graupel but no slab present above just low-density storm snow. Graupel layer was not widespread throughout below treeline northerlies limited to terrain features that were drifted after Friday’s storm on terrain features that were slightly tilted to the east.

Photos:

Schuylkill skier triggered slide

Location: Crested Butte Area
Date of Observation: 03/19/2018
Name: CBAC

Subject: Schuylkill skier triggered slide
Aspect: East
Elevation: 11,200′

Avalanches:

Skier triggered slide spotted from the valley. SS-AS-R1/D2-I.  Triggering party said “Ran on sun crust. Soft and ran like slough”.

Photos:

Remote trigger in Red Well

Location: Crested Butte Area
Date of Observation: 03/16/2018
Name: Dave

Subject: Remote trigger in Red Well
Aspect: North, North West
Elevation: 12, 300

Avalanches:

We skied a lap in red lady bowl, then went back up and dropped into red well. Remotely triggered a slide from the bottom on red well, 1st skier triggered the slide. It was a R1, D2.

Weather: Overcast in the Am cleared to sunny
Snowpack: New snow 3-5 in of new snow. Was deeper in loaded areas we skied. Did not see signs of instability of during tour.

Photos:

Crown roughly 24 of 4-finger drifted new snow.

Remote triggered from the furthest looker’s right point.

Fresh avalanche in Red Well, 2/16/2018.

Snodgrass

Location: Crested Butte Area
Date of Observation: 03/16/2018
Name: ADB

Subject: Snodgrass
Aspect: East, South East
Elevation: BTL

Avalanches:

Starting zone on slope greater than 30 degrees, cause loose slough (4 inches deep) which picked up more snow for about 300 feet. Snow piled up enough to bury one’s dog or knock you off balance.
On a a slope between 25 and 30 degrees, started another loose slough, which didn’t have the slope and energy to travel more than 25 feet.



Weather: Mixed weather: S-1/obscured skies/clear skies
light breeze

Snowpack: Between two to four inches of new snow on sun crusts in last 24 hours.

Photos:

Coney’s

Location: Crested Butte Area
Date of Observation: 03/15/2018
Name: Ben Pritchett

Subject: Coney’s
Aspect: North East, East
Elevation: 9-10,900 K

Weather: Convective showers all day, adding up to 2-3″ of snow by 3pm. Very greenhouse feeling, w/ intense radiation between the bursts of snow. Light southerly winds.
Snowpack: Dense rimed snow fell on wet snow surfaces. Very good bond between the saturated surface and the new snow initially, though it’s worth checking for “dry snow over melt layer” faceting at that interface in the near future as that interface freezes. Boot penetration was 10-20cm outside of very shallow isothermal areas. The melt water of the last couple days has changed the BTL snow surfaces to a very dense and consolidated cap over the old weak snow.

 

Snodgrass N-NE Ski tour

Location: Crested Butte Area
Date of Observation: 03/15/2018
Name: Chris Martin

Subject: Snodgrass N-NE Ski tour
Aspect: North, North East
Elevation: 9400′-1100′

Avalanches:

NO

Weather: WEATHER: Snow S-1,2,3 and BKN sky fluctuating back and forth throughout the day. Trend continued all the way ‘till 1600 when we exited the field. Virtually no winds except for around 1500 down valley winds.
Snowpack: Snowpack/Avalanche OBS:
Whump observed on flats touring up WG to Snodgrass, localized cracking only around skis. W aspect. No Slab Structure present. @ 10,000’ where whump occurred.

HS varied from 60-120cm. Persistent slab structure is present on the northerly aspects on Snodgrass, decreasing slab thickness as the aspect tilted more easterly. A few deep hand pits showed moderate to hard results failing above a stout MFcr @ 40 cm down on a NE aspect. On a N aspect, similar results, breaking on .5-1mm rounding facets and evidence of minimal MF/cr. Slabs above weak layer comprised of 4F-1F hardness. The 4f upper pack is comprised of rounding facets. No avalanches observed today. Without digging to ground, with ski pole pentrometer, feels as 1F slabcontinues to depth hoar above ground. Supportable boot pen all over snodgrass N at top of ski run @ 11,100’

The greenhouse effect is full on in the zone creating crusts further and further into the N aspect zone.

HN: 5cm observed at top of snodgrass

1100: 2C at 10000’. No winds

1315: 1C, calm down valley winds. BKN/Sun at top of snodgrass.

1430: S1 (Gruapel) Increasing clouds, THUNDER observed for 5 minutes with the very short period of graupel.

Photos: