Date of Observation: 03/12/2021
Name: Zach Kinler, Zach Guy, Jared Berman, Jack Caprio
Zone: Southeast Mountains
Aspect: North East, East, South East, South
Elevation: 8,800-12,200

Avalanches: 1 small windslab on a northeasterly alpine feature.

Weather: Mostly sunny, calm winds in sheltered terrain below treeline with moderate to strong winds on ridgleline. Generally warm temps with freezing level near 11K.

Snowpack: Thin and weak below treeline with dry snow on the northern half of the compass with moist snow and softening crusts on the southerlies. Due south at lower elevations was a thick fully supportable crust. This crust became soft and thin as you moved towards East and on a NE aspect just below 11k there was no crust present. This location had previously avalanched and was only harboring 60 cm of all weak and faceted snow. The 3/10 interface(1-1.5 mm NSF) is buried about 20cm below the surface and quite weak.

Moving up in elevation to just below 12,000 we targeted an easterly aspect focusing on the deeper weak layers from December and January. The December weak layer was Fist hard, 4 mm dry Depth Hoar with little to no rounding occurring. Long column results on this layer were ECTX with a PST 40/100 END down 100 cm indicating this layer is currently unreactive but still holding the potential to propagate a failure. Identical results were observed on the 1/19 layer(down 75 cm) at this location.

Winds were blasting and swirling snow more than building slabs, other than isolated and small pockets.

Date of Observation: 03/11/2021
Name: Zach Guy

Zone: Southeast Mountains
Aspect: North East, East
Elevation: BTL

Avalanches: On a NE aspect BTL, I skier triggered a couple of shallow soft slabs breaking on the recently buried near-surface facets, that then plowed deeper into the weak snowpack. 6″ thick, D1 in size, ran a few hundred feet.
Snowpack: Quick tour to hone in on the distribution of persistent weak layers below treeline near town before the upcoming storm. Generally, anywhere that the current conditions are soft (northeast aspects), there are .5mm to 1.0 mm facets below recent snow and in some cases, thin soft crusts. The crusts become thicker and should handle more of a load on due east or anything south of that. The transition from good to bad happens around ENE.

Photos:

Date of Observation: 03/10/2021
Name: Eric Murrow

Zone: Southeast Mountains
Location: Coney’s
Aspect: North East, East
Elevation: 9,500 – 10,900′

Avalanches: While on tour visibility obscured nearby terrain. Took a pavement tour later in the afternoon during a clear period and was able to gaze at many drifted features around the area and was not able to spot any fresh activity.
Weather: Mostly cloudy skies from 930 to 1230. Very light snow without any real accumulation during this period. Moderate westerly winds at ridgetop with some transport observed.
Snowpack: Measured 6″ new w/ .45″ SWE at 10,700 feet (noon). East slope at snow measurement site had 3-4cm melt/freeze crust (not quite supportive to skis) underneath new snow with ice columns present around 30cm down from crust. While walking ridgeline I produced two moderate collapses on wind drift/lip that produced shooting cracks up to 50 feet – cracks only ran through drift and not into steeper, less drifted terrain below. Drifts were on sub 30 degree terrain so did not run after failure. These isolated drifts were up to 40cm thick with ski penetration at approximately 15cm. Other nearby leeward features had drifted up to 30cm immediately below ridgetop but were much softer and did not produce any cracking.

Date of Observation: 03/10/2021
Name: Alex Tiberio

Zone: Southeast Mountains
Location: Gothic
Elevation: 9500

Photos:

Date of Observation: 03/10/2021
Name: billy barr

Zone: Southeast Mountains

Weather: Obscured and with off and on snow starting towards midnight. Strong wind has made for drifting snow and blizzard conditions. There was 4″ new snow and water 0.39″ with 44″ on the ground. Wind has been generally moderate with strong gusts up to around 40 mph. Currently obscured with light snow but wind continues, though gusts down to 25 now. Yesterday high was 44F and the current is 16F which is the morning low. It is generally blizzard conditions.

Date of Observation: 03/07/2021
Name: Ian Havlick

Zone: Southeast Mountains
Location: Red Coon Glades
Aspect: East, South East, South, South West
Elevation: 9000-11,200

Avalanches: Only fresh avalanche observed today was the D1.5 wet loose in Red Lady Bowl.
Weather: Solid inversion this morning with valley temps in teens and 12,000 not dipping below 25F. Very light westerly winds, rapidly warming temperatures between 8:30 and 10:30am. Overcast skies for most of the day aided the greenhouse effect and snow surface warming.
Snowpack: Snowpack started with a decent freeze below 10,500ft, but quickly softened on southerly facing BTL and NTL terrain by 10am, especially above the inversion (~10,500ft). Persistent slab structure in all south facing elevations today, but not until the more open “Red Coon Glades” that we found alarming, punchy, wet snow. After pole probing tipped us off to the poor, unconsolidated structure, I jumped to demonstrate to the level 1 students how punchy the snow had become and initiated a large “whumph” across the whole 24º steep meadow. We pulled the plug on the rest of our ascent after I dug a subsequent test pit and got an ECTP14 SC on moist large grained depth hoar 80-100cm deep (near ground, Dec 10th DH). On a small south facing test slope near the parking lot, initiated a 10’x10′ wet slab to fail and slide 4-6″ in a relatively shallow snowpack area, ~38º in steepness.

Factors that lead to turning around:
1. recent wet slab avalanche in nearby Coon Basin, similar aspect and elevation
2. Signs of instability, whumph
3. Propagating extended column test with moderate loading step on moist depth hoar near ground
4. Poor re-freeze above valley inversion
5. rapid temperature rise, and 3-4th day of above average temperatures.