Date of Observation: 03/30/2021
Name: Billy Barr
Zone: Southeast Mountains
Location: Gothic Townsite
Weather: Snow started near 11 p.m. and was steady but light through the night, though denser than of late. there hs been 3½” new with water 0.30″. Wind was strong at first getting lighter through the night and now almost calm. Currently overcast with light snow. the high was 45F, low 21 and the current 21. The snowpack is at 45″. billy
Date of Observation: 03/29/2021
Name: Eric Murrow
Zone: Southeast Mountains
Location: West Brush Creek towards White Mountain
Aspect: North, North East, East, South East, South, South West, West, North West
Elevation: 9,000 – 12,300′
Avalanches: Lots of previous Wet Loose from steep sunny areas all small in size. Did not observe any fresh loose avi’s while in terrain between noon and 5pm. One fresh Wind Slab observed at 12k on NE slope.
Weather: Mostly clear skies with warm temperatures. Strong SW winds at upper elevations with gusty conditions below treeline. Snow transport was generally inefficient due to high speeds blasting snow into the atmosphere; isolated features picked up loading.
Snowpack: Traveled through a shallower part of the forecast area moving through shady slopes near and above treeline. Snowpack on north and northeast slopes at upper elevations was generally in the 130 to 180cm range. A test profile in a drifted location(northeast) with 200cm had a slab around 55cm thick (up to 1 finger hard) resting on the mid-March weak layer and did not produce results in standard test but hard hammering was able to get a propagating result. At a shallower location with HS around 135cm, I tested the basal weak layer which produced a moderate propagating result in the Depth Hoar (4-finger minus hardness) near the ground. Even though triggering a large avalanche in old, weak snow at the ground is on the low end of the probability scale, the variability of snow depth in this part of the forecast area made me a bit selective with my terrain choice by avoiding rocky, variable depth slopes.
Briefly traveled across a few sunny features between 10,000 – 11,200′ and found a few inches of wet snow at the surface, but no significant Wet Loose problem. I suspect some steep, wind-protected sunny slopes were in condition for human-triggered small Wet Loose slides. Low elevation northerlies became moist by the afternoon, but neighboring steep slopes did not produce any natural activity.
Photos:
Date of Observation: 03/29/2021
Name: Jack Caprio
Zone: Southeast Mountains
Location: Mount Emmons
Aspect: North, North East, East
Elevation: 9k-12.5k
Avalanches: Small wet loose activity on east-facing slopes of all elevations. SW and W facing slopes had more wet loose activity below treeline due to winds keeping alpine surfaces cool. NE below treeline got in on the action too in the happy chutes (see photo).
Weather: Few clouds. Warm temps below treeline. The alpine was very breezy with consistent moderate SW winds along with strong gusts.
Snowpack: Isolated 2-5 inch wind pockets on NE and E facing terrain near ridgeline. Previous tracks from yesterday in a steep alpine chute had been erased overnight due to wind-loading. Although the wind slabs were very small, it was still enough of an issue for us to avoid a very steep, exposed, slightly cross-loaded chute. We chose to descend a steep, planar north-facing slope away from any ribs or other features prone to cross-loading. There were no signs of instability on our descent.
The snow stayed dry on due north slopes. Below treeline NE-E facing slopes became moist by early afternoon as expected.
Photos:
Date of Observation: 03/27/2021
Zone: Northwest Mountains
Location: West Elks
Aspect: South East, South
Elevation: 12,000′
Avalanches: Other than some smaller sheds of recent snow attributed to solar warming below rock bands and such, no recent notable avalanches observed. While traversing the ridge to access our ski line, my partner put a left ski just a little to far out on a big cornice and punched through far enough to trigger a school bus-sized cornice fall. The ridge is very sharp (knife ridge) in this particular spot and his right ski didn’t leave bare rock on the windward side of the cornice when it failed. Fortunately, my buddy was in a safe enough location to not take a ride, but it was certainly a sobering reminder to give every cornice it’s due respect and always ensure you are in a safe place when negotiating the beast. It was a big cornice failure and entrained localized snow on it’s descent, however, it didn’t propogate much beyond the immediate path. Probably ran around 1000′. This cornice, as I assume most are currently, was primed and ready to go. The pictures come from my flip phone, so I apologize for the poor quality.
Weather: Ridge winds were moderate from the North. Pretty pleasant on the climb to the ridge. Lots of sun.
Photos:
Date of Observation: 03/28/2021
Name: Zach Guy
Zone: Northwest Mountains
Location: Ruby Range
Aspect: North, North East
Elevation: 9,000 – 12,100′
Avalanches: 2 recent cornice falls. One on Garfield Peak plowed to the ground in a steep, rocky feature (D1.5), one on Owen triggered several layers of slab avalanches and ran impressively far (D2).
Dozens of small wet loose avalanches from yesterday, generally D1. Wet activity continued today.
Weather: Light winds this morning, some moderate gusts midday. Clear skies and warm temperatures.
Snowpack: Wet loose activity: below treeline east and a few northeast aspects were active today, south aspects are transitioning to stable corn snow. Near and above treeline, activity continued on east, southeast, and south aspects. We finished the tour before westerly aspects warmed up.
We rode steep north and northeast facing terrain with no signs of instability, these slopes were either scoured or protected from yesterday’s northerly winds. There was a northwest facing slope that we avoided after probing revealed a poor structure (~2′ -3′ slab over weak facets). Based on debris evidence, it looked like this slope had avalanched earlier in the year.
Photos:
Date of Observation: 03/27/2021
Name: Jack Caprio Zach Guy
Zone: Northwest Mountains
Location: Kebler Pass
Aspect: North, North East, East, West, North West
Elevation: 9,400-12,500
Avalanches: 1 intentionally ski-triggered wind slab avalanche on heavily loaded east-facing test slope above treeline. The crown ranged from 6-24 inches. The larger part of the crown (2 ft) was the trigger point. This was the most windloaded area on the slope. The crown pulled back about a foot above the skier but the skier was able to easily ski out of it because the slope was small. A couple of other small slabs in the area that released in the past 12 hours or so from wind effect.
15-20 small loose wet avalanches on sunny near and above treeline terrain. The near treeline elevation band had a more widespread avalanche cycle due to continued winds and cloud cover above treeline helping keep surfaces cooler and denser.
Weather: Few to scattered skies throughout the morning. Clouds cleared around 3pm as the solar intensity increased. Moderate northwest winds with strong gusts.
Snowpack: Recent storm snow consisted of about 10-12 inches earlier in the day. This new storm snow rapidly settled to about 8 inches on E and W aspects as the snow moistened. Numerous rollerballs and pinwheels observed. The snow stayed dry on steep north aspects.
Above treeline, NW and W winds continued to deposit snow onto leeward ridgelines. In the alpine, we chose to stick to terrain that had not previously avalanched during the February cycles. Very small wind slab pockets were our only signs of instability on alpine N-facing terrain.
Photos:
Date of Observation: 03/27/2021
Name: Evan Ross and Zach Guy
Zone: Northwest Mountains
Location: Ruby Range
Avalanches: See photos and captions. A handful of slab avalanches, D1 to D2 that ran in the last day or two. These appeared to generally involve just the new and windblown snow from the past few days, or wet sluffs today. One on the NE face of OBJ was thick enough it might have broken into older layers, although it was too far away to say anything with confidence.
Photos:
Date of Observation: 03/27/2021
Name: Ian Havlick and Evan Ross
Zone: Southeast Mountains
Location: Whetstone and near Copper Lake
Aspect: East, South
Elevation: ATL
Avalanches: See photos
Fresh avalanche (appears to be a persistent slab) on an east aspect ATL of Mt. Whetstone, D2 in size.
Smaller wind slab avalanche on a south aspect above Copper Lake, D1.5 in size
Photos:
Date of Observation: 03/26/2021
Name: Zach Guy and Jack Caprio
Zone: Southeast Mountains
Location: Mt. Emmons
Aspect: North East, East
Elevation: 9,000 to 11,500′
Avalanches: One small wind slab likely ran naturally yesterday in Coon Basin (SE aspect, ATL).
Skier triggered a handful of shallow sluffs on steep, northerly terrain, about 6″ deep or less.
Weather: Afternoon tour brought overcast to broken skies. Brief convective pulses of moderate snowfall (S2) with an inch or so of accumulation, generally light winds with a few stronger gusts associated with the snow squalls.
Snowpack: Looking for feedback for persistent slabs in the type of terrain we’ve been warning about: shallow/previously avalanched, previously windloaded. Slabs are getting a little thicker now and we didn’t feel comfortable ski cutting or really getting onto suspect slopes to get a feel for how reactive they are. A few strategically placed pits along flanks or smaller terrain features produced a mix of propagating and non-propagating results on fist hard facet layers (1.5-2.0mm) on old bedsurfaces, generally 45 to 65 cm deep. The most concerning structures and a propagating result were on slopes where previous wind drifting created denser, harder layers above these buried facets, making for a more dramatic hardness change at the weak interface. Wind sheltered terrain held a softer slab and a less-distinct transition to these facets, with non-propagating results. Previous wind drifting and scarier structures were not apparent on the surface, but evident with probing or an understanding of local wind patterns. We avoided those types of slopes.
Photos:
Date of Observation: 03/26/2021
Name: Evan Ross
Zone: Southeast Mountains
Aspect: East, South East, South
Elevation: 9,300-12,300
Weather: Calm to light winds with a few stronger gusts transporting snow. Mostly cloudy sky with convective cells moving through and creating quick bursts of snowfall. Maybe an inch or two of new snow accumulation today, but it was settling quickly.
Snowpack: Potential wind slabs were small and from what I observed were really confined to right near the ridgeline or cross-loaded terrain features. Otherwise, the cream was getting thicker with periods of sun between the clouds. Similar to yesterday’s ob in Washington Gulch, there was about 4″ of recent snow accumulation down low and around 8 to 10″ up higher. No avalanche problems were observed outside of the potential wind-loaded terrain features. One snowpit at 11,300ft on a 33 degree south facing slope had about 8″ of new snow on top of a very stout crust with a matrix of other stout crusts and percolation columns below.
