Observations

Date of Observation: 03/07/2021
Name: Zach Guy

Zone: Northwest Mountains
Location: Ruby Range: Upper OBJ Basin
Aspect: North East, East, South East
Elevation: 10,500 – 12,800′

Avalanches: Widespread wet avalanches from the past few days on E, S, and W aspects; mostly D1 to D1.5 in size a couple D2s. Most of these were either wet loose involving the recent snow or thin soft slabs (6 to 8″ thick) triggered as the recent snow got moist or wet. One was a large wet slab that failed at the ground several feet thick on a south aspect NTL of Schuylkill Ridge. We only saw one wet loose run today (hard to keep track though), but it was easy to trigger small wet sluffs on test slopes.
There were several dry storm slabs that ran last Thursday on northerly aspects.
There was also some impressive persistent slab activity from February that we haven’t gotten views of yet, including several D2.5’s to the ground on south/southwesterly aspects of Schuylkill Ridge, and debris piles pushing D3.5 or larger off of the NE and SE sides of Afley, and perhaps the NE side of Purple.
Weather: Cancun 2021. Warm, sunny, light winds. Thin clouds midday seemed to slightly diminished solar warming,
Snowpack: HS below treeline is 200 cm, HS on a fairly representative alpine feature 250 cm. About 15 cm (6″) of settled storm snow from Thursday. The upper snowpack was frozen solid this morning and starting thawing around 9 to 10 a.m. on easterly aspects. By 11, it was easy to trigger pinwheels and small sluffs involving the recent snow on SE aspects. No signs of instability on shady slopes

 

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Date of Observation: 03/06/2021
Name: Ben Pritchett

Zone: Northwest Mountains
Location: Heli flight along the Elk Mountains Grand Traverse route
Aspect:
Elevation:

Avalanches: Remarkably few recent avalanches. Only observed one fresh Wet Slab avalanche, and no previously unreported Wet Loose avalanches. We saw numerous large Persistent Slab avalanches seen from the mid-February avalanche cycle, but these were primarily restricted to near treeline, in areas of generally weaker, shallower snow cover. High alpine terrain showed few signs of large to very large avalanches. Those Persistent Slab avalanches seen tended to be wind-loaded features lower on the mountain in areas with weaker snow cover. The big alpine paths in the Star Pass area have not yet gone through a major avalanche cycle this season.
Weather: Hot and calm
Snowpack:

Photos:

Date of Observation: 03/06/2021
Name: Eric Murrow Jared Berman

Zone: Northwest Mountains
Location: Baldy south side and northwest side
Aspect: East, South East, South, South West, West, North West
Elevation: 9,400′ – 12,400′

Avalanches: Observed a healthy number of small D1 loose avalanches from Friday throughout Ruby Range (most originated from steep rocky areas with some degree of southerly tilt), but did not notice any fresh avalanches today. Returned to town at dark, so was unable to look around the range from the pavement with binos.
Weather: Thin high cloud cover, very warm temperatures, and generally light winds 5 -15mph above treeline.
Snowpack: Ascended southerly-facing terrain that had soft, slightly moist surfaces up through 12k by noon. Descended down through northwesterly terrain near treeline and found surprisingly soft surface conditions. Ascended back up through said NW near treeline terrain and probing revealed HS between 120cm and 220cm. We dug a test profile at a site with HS of 150cm and found around 115cm slab resting over weak Depth Hoar at ground (4finger- hardness) – ECTX and PST 52/110 END. Here there are two layers of concern, basal depth hoar and weak near-surface facets buried by 20cm of recent snow.

Late in the day we traveled over E, SE, S, and SW slopes near treeline and found wet snow conditions. On a SE slope at 11,600′, with HS of 135cm, meltwater has percolated about 75cm down.  A weak facet/crust layer just above ground has yet to see water infiltration. I would anticipate liquid water to reach the ground at this site within the next two days if forecasted temperatures verify Sunday and Monday. One SW feature at 10,800′ had trenchy, wet conditions as we skied over with a dramatic increase in ski pen around 10-12 inches.

Date of Observation: 03/06/2021
Name: Andrew Breibart

Zone: Northwest Mountains
Location: GMT Reduction (East River-Paradise Divide-Washington Gulch)
Aspect:
Elevation: BTL, NTL

Avalanches: didn’t take pictures of the wet loose avalanches on south aspects of Baldy and east aspects of Gothic.

1. Mt Belleview-NTL on W/SW aspect: slab avalanche (D1 to D2) CBAC NOTE – reported 2/22 ob here
2. Mt. Baldy-NTL on SW aspect wet slab
3. Coneys-BTL on E/NE aspect: slab (D0.5-D1) CBAC NOTE – reported 3/2 ob here
Weather: Temperatures remained lower than yesterday’s sauna due to thin cloud cloud cover. Calm.
Snowpack: snow is transitioning rapidly on southern aspects BTL as a melt freeze crust develops.

Photos:

Date of Observation: 03/05/2021
Name: Eric Murrow

Zone: Northwest Mountains
Location: Snowmobile journey to Beckwith Pass and up into Evan’s Basin on Mount Emmons.
Aspect: East, South East, South, South West, West
Elevation: 8,900′ – 11,200′

Avalanches: Observed loose snow avalanches on sunny slopes near and above treeline, generally coming from warm, rocky terrain features. Up to D1.5 in size. Overall significantly less activity than I expected to find. See photos for examples. Observed one natural run on alpine SE slope at 1:30 pm.
Weather: Clear skies, light winds, and warm temperatures above freezing.
Snowpack: Around 7″ storm snow on top of Kebler Pass and Beckwith Pass.  5″ on lower flanks of Mount Emmons.

I targeted a shaded slope in a shallower snowpack area on the far west end of the forecast area near Horse Ranch Park. I found HS 120cm with dense slab around 75cm thick sitting on old snow from early in season – ECTP 28 x2 result failing in oldest weak snow near ground. 1/19 interface shows clear sign of rounding and no result here. Oldest snow at ground was 3-4mm Depth Hoar – it is starting to round and sinter with around 4finger hardness. Late February weak layer is down 20cm, .5 -1mm facets with ECTN 11 and easy Shovel Tilt Test results.

In the afternoon traveled on southerly-facing slopes checking in on where liquid water was in the snowpack. On several slopes found moist snow from the surface to the ground. Ice columns from percolating meltwater was found nearly all the way to the ground – with around 20cm of moist, 4finger hard snow at the ground without ice columns. Tests produced no result on these slopes even while hammering on the column until my hand hurt. See photo of ice columns.

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Date of Observation: 03/05/2021
Name: Evan Ross

Zone: Northwest Mountains
Location: P-Divide
Elevation: 9,000-11,800ft

Avalanches: Wet loose avalanches happened, but no widespread and all on the small size. Some east, some south, some west, they all had a little action.

Weather: Calm winds, warm temps, clear sky, beautiful.

Snowpack: Well, that snow sure was good while it lasted! Lots of now crusty snow surfaces heading into tomorrow, until they warm back up again… The recent snow seemed to just bake in, more than release as wet loose avalanches. Hard saying just how reactive it will be on the next warm-up after today. We slammed a whole lot of terrain features, many in the upper 30 degrees, and didn’t find any signs of instability regarding PSa. Still considering regrouping areas for the low likelihood avalanche problem. If anything, upper elevations looked like the best chance to find a thick snowpack transitioning to a thin snowpack due to previous winds.

We descended a SW aspect between 11,000-10,00ft at 3:30pm with slope angles in the upper 30 degrees. The new snow on that slope felt more baked in and we didn’t see any movement.

Date of Observation: 03/05/2021

Author: Jack Caprio

Zone: Crested Butte Backcountry

Spring break is upon us. Temperatures are climbing and our snowpack has begun the annual springtime transition. See all the recent action here.

Date of Observation: 03/05/2021
Name: Jared Berman, Zach Kinler
Zone: Northwest Mountains
Location: Anthracites
Aspect: North, North East, South East, South
Elevation: 10,000′- 11,500′

Avalanches: From a distance, we could see several small loose wet avalanches initiating below rock bands on steep east and southeast facing terrain in Elk Basin and Evans Basin near treeline.

In the Anthracites, one D1.5 natural loose wet was observed below treeline on a southeast slope while another was intentionally triggered on a south facing slope. Both ran into the basin locally known as the Playground (see photos below).
Weather: Clear skies, calm winds, and above freezing temperatures.
Snowpack: Drastically variable snowpack depending on aspect below treeline and near today.

On north and northeast facing slopes, probing revealed the average snowpack depth being 150cm deep with some areas as deep as 200cm. We measured 8″ of new snow on these slopes with 0.75″ of snow water equivalent. We did observe faceted grains at the old/new interfaced as well as small faceted grains at the snow surface.

On south and southeast facing slopes below treeline, the snowpack averaged 90cm deep. A hasty pit revealed moist snow all the way down to the ground with obvious signs of free water(vertical and horizontal ice columns)  through the upper half of the snowpack.

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Date of Observation: 03/04/2021
Name: Evan Ross

Zone: Northwest Mountains
Location: Washington Gulch
Aspect: East, South East, South, South West, West
Elevation: 9,400-11,400

Weather: Good Pulse of snow in the morning, then waited most of the day for things to pick back up. Headed out in the late afternoon. Periods of heavy snowfall. Mostly calm winds with some strong gusts.

Snowpack: A couple of inches of new snow near the Washington Gulch Trailhead, and about 5 inches of new snow near the head of Washington Gulch. In the alpine there may have been a little drifting and some slab formation, otherwise where I traveled the new snow didn’t make any change. Small sluffs on steep northerly-facing slopes would be about it. I didn’t find enough snow to sluff on the crusty southerly-facing slopes.

The recently buried crust on southerly-facing slopes was a couple of inches thick. Boot pen mostly punched through the crust to about 30cm. Interestingly, most of those crusts also had percolation columns extending into moist or even dry snow below.

Sunny slopes are setting up nicely for a loose wet avalanche cycle when the sun comes out, otherwise, the new snow is mostly adding to sluffing volume on northerly-facing slopes.

Date of Observation: 03/03/2021
Name: Evan Ross Zach Kinler

Zone: Northwest Mountains
Location: Angle Pass
Aspect: North East, East, South East, South
Elevation: 9,700-12,000

Avalanches: Several loose wet avalanches. A few old ones and some that ran today. Not widespread and mostly D1 in size with a couple D1.5s. SE, S, SW aspects had the majority of the activity.

Weather: A light breeze at 12,000ft, otherwise no winds. Hot… my face hurts.

Snowpack: We didn’t end up having to manage any wet avalanche concerns. Between 10am and 12:30pm we traveled on south and southeast slopes up to 11,800. The upper 3 to 5cm of the snowpack was wet, while the snow below remained dry. By the time we traveled back through similar terrain the surfaces were starting to crust due to lower sun angles and/or shading.

We mostly traveled on E and NE facing slopes in the afternoon. Some east facing slopes had a crust on them in the afternoon, but were mainly traveling through soft cold snow. Where that snow was soft and cold the upper snowpack was weak NSF, or firmer wind effected snow surfaces.

The snowpack we traveled on was otherwise deep and we didn’t encounter much of a concern on the persistent slab avalanche front.