Location: Kebler Pass Area
Date of Observation: 02/20/2020
Name: Ian Havlick
Subject: Explosive Triggered Avalanche Irwin
Aspect: West
Elevation: 11,500

Avalanches: Persistent slab avalanche 40-100cm deep, 1F hard failing on 4mm depth hoar in terrain not really touched yet this season with ski traffic or explosives. 15# explosive triggered small pocket which gouged as it ran. Impressive debris and similar to other slides we have triggered within the past 2 weeks in similar terrain.

Weather: clear, calm, strong solar radiation.

Photos:

Location: Brush Creek Area
Date of Observation: 02/20/2020
Name: Eric Murrow
Subject: West Brush Creek
Aspect: East, South East, South
Elevation: 9000′ – 11800′

Avalanches: Viewed a couple more recent (failed early in the week) small slabs on east and northeast slopes near and below treeline.

Weather: Clear skies, cold valley bottom in moring gave way to mild air temps, and light winds.

Snowpack: Traveled to about treeline on Teocalli and dug a couple of test profiles – one on southeast(treeline) and another on an east slope(upper end of below treeline elevation) (see photos). Test results indicated that triggered avalanches remain possible. Sunnier slopes near and above treeline have crust/facet combinations with slabs resting above (likely similar structure to natural avalanches observed over the past week on south and southeast alpine slopes) and shaded slopes at upper end of below treeline elevation band have a very weak layer in middle of snowpack and near ground with a cohesive slab above. While stepping out of profile pit on E slope at 11000′, my partner and I produced a collapse in the snowpack that traveled several hundred feet but did not produce an avalanche on slope below (see photo).

Photos:

Location: Kebler Pass Area
Date of Observation: 02/19/2020
Name: MR
Subject: small windslab
Aspect: North East
Elevation: 11,300

Avalanches: Intentionally triggered small windslab just below ridge top at the entrance to a north facing chute. See photo.

Location: Crested Butte Area
Date of Observation: 02/19/2020
Name: Zach Bauer
Subject: Unemployment Column test
Aspect: North
Elevation: 10000

Avalanches: none on the sheltered chutes.

Weather: High level clouds and a calm day, not too warm.

Snowpack: Dug a pit at 10000′ on the north aspect of the Unemployment Chutes. The pit was 3′ deep, the recent storm snow failed during a column test at 2 hits from the elbow. The base of the column disintegrated at 3 hits from the shoulder. The basal layer is extremely faceted and empty faceted snow. The snowpack is currently 1/2 faceted sugar in the bottom half, and the rest is a firmer layer of two week and week old snow. Distinct failures at both the storm and old snow interface, as well as the faceted vs unfaceted snow down lower. The conditions in the sheltered glades gave the green flag for a good decent back to town.

Location: Paradise Divide Area
Date of Observation: 02/18/2020
Name: Eric Murrow
Subject: Paradise Divide West-Facing Below Treeline
Aspect: South, South West, West
Elevation: 9000′ – 11000′

Avalanches: A couple of recent Wind Slabs on alpine terrain
Mineral Point SS-R1-D1-I south – cross-loaded
Purple Ridge SS-R1-D1-I southeast
Mineral Point SS-R1-D1.5 east

Weather: Mostly clear skiers with thin high clouds. Cool temps but very comfortable in the sun. Light westerly winds. Small amounts of transport on a few of the highest and most exposed peaks.

Snowpack: Tour through west-facing slopes below treeline. In more “sheltered” west terrain found HS around 130-150cm. Locations with deeper snowpack on these aspects showed significant rounding and sintering of large grains facets and depth hoar in the bottom of the snowpack – often 1 finger hardness. Shallower parts of terrain from wind scouring felt much weaker via probing. Two layers of concern were found at this site, the first was a graupel/”rimey” crust interface that formed on the afternoon of Sunday 2/16 (very little load above yet but may become on problem with next loading event) and the 2/3 interface now buried by about 40cm of snow. Slab is up to 1 finger hard above the 2/3 interface. Weak layer is 1-1.5mm facets sitting beneath an ultra friable crust(the crust is of little concern as the slab above is plenty strong to propagate).

Traveled through a southerly facing cross-loaded feature at 11,000 feet and found drifts over a foot deep from the past few days to be unreactive without any cracking.

Photos:

Location: Kebler Pass Area
Date of Observation: 02/18/2020
Name: Ian Havlick
Subject: Ruby Peak
Aspect: South East, South, South West
Elevation: 10-12,800ft

Avalanches: No fresh avalanches within the last 24hrs although there were a few shallow wind slabs that looked to had failed late in Mondays exiting storm.

Weather: Few clouds, strong solar radiation (short-sleeved on most of skin up), light SW winds, no wind transport except visible plumes near Chair Mtn toward Marble around 1500. Radiation was strong, but cold temps.

Snowpack: Upper Snowpack was quickly moistening from solar and will be crusty in the morning on southerlies. DId not dig, but could feel several thin crusts in upper 3ft of snowpack that spooked me a bit. Aborted plans to center punch Ruby when pole probing revealed same fragile melt-freeze crust buried 2-3ft deep under increasing density snow and wind load from last few days.

Location: Crested Butte Area
Date of Observation: 02/18/2020
Subject: Remote trigger from above, second bowl Snodgrass
Aspect: North East, East
Elevation: 10800

Avalanches: Remote trigger from above of second bowl, as I step out of skin track, 30-35 ft away from crown, heard a whomp, and skin closer to edge to take look.. and saw the avalanche release, fortunately had no intentions on skiing that slope.
Second bowl snodgrass, from top of steep nose.
Aspect ENE (60º), slope estimate 40-45ª, elev. 10800, around 1:30pm, Soft Slab (SS) (35-45cm crown 4F over, F bed surface possible weaker layer on interface), avalanche release (AS), uninetecional (U), size D1.5-D2, bed surface (I), weak layer, facets or surface hoar, slab thickness (decomposed snow and or wind packed particles) 35-45 cm, slab width estimated 150ft, vertical fall estimated 300 ft, length of path run, 550-600ft., avalanche started at rollover on clear slope from trees near the ridge.

Weather: Clear, wind calm.

Snowpack: Just did very fast hardness test, Slab 4F bed surface F, with a weaker interface layer.