Date of Observation: 02/26/2021

Zone: Southeast Mountains
Location: Cement Drainage
Aspect: North East, East, South East, South, South West
Elevation: 10,300′-12,100′

Avalanches: Everywhere in sight, especially E facing terrain. D1-D2+ on virtually any alpine feature which took on drifting recently, along with some unusual NTL/BTL features which normally wouldn’t be suspect. Most of the recent avalanches we observed today have already been reported, but not all of them. Basically, if you looked below a cornice on a leeward aspect, it went big. Sorry, no pictures.
Weather: Windy. Steady and swirling winds, mainly out of the W/SW at 10-20 mph all day. Probably was gusting to 30+ at higher elevations based on the flagging we observed off many of the surrounding peaks. Air temp wasn’t as cold as we expected this morning. My car read 18F at TH at around 9am. Apart from the consistent and gusty strong winds, air temp seemed pretty mild for the majority of the day.
Snowpack: Mainly traveled on W/NW BTL and NTL, but also had a quick transition on a southerly aspect NTL. Snowpack depth was relatively uniform. Pole probes went to ground at 110cm-130cm. On the ridgeline, where the wind has stripped the majority of the season’s snowpack, depth was around 30cm. Snow was supportive on all aspects we traveled, with a ski pen of around 3-6.” Once we stepped off our equipment though, boot pen went to ground with full weight. For the most part, the skiing was surfy and supportive. However, variable crusts exist on the sunny aspects and wind-affected terrain, of course.

Date of Observation: 02/26/2021
Name: Andrew Breibart

Zone: Southeast Mountains
Location: Red Lady Glades and CB Nordic Trail
Elevation: BTL

Weather: Keystone snow course/Red Lady Glades: obstructed skies and strong winds. colder temperatures before 9AM
Crested Butte snow course/CB Nordic Magic Meadows yurt: few clouds and light winds with moderate gusts and warming temperatures between 10 AM and 12PM.
Snowpack: Keystone snow course: 2.54 cm (1 inch) melt-freeze crust on the surface. Snow depth ranged between 68 and 112 cm (27 and 44 inches) across 41 meter (135 foot) transect with 5 samples.
Crested Butte snow course: depth ranged between 86 and 107 cm (34 and 42 inches) across N to S transect of 122 meters (400 feet) and W to E transect of 74 meters (244 feet). melt freeze crust 61 cm (24 inches) below surface (1/19 or 2/5 interface?).

Photos:

Date of Observation: 02/24/2021
Name: Alex Tiberio

Zone: Southeast Mountains
Location: Gothic

Photos:

Date of Observation: 02/23/2021
Name: Jack Caprio and Eric Murrow

Zone: Southeast Mountains
Location: North Cement Mountain
Aspect: North, North East, East, West, North West
Elevation: 9,000′-12,200

Avalanches: Observed a number of avalanches on Cement Mountain of varying ages from the past month.  Included images for avalanches that likely failed around the Feb 13/14 time frame.  Most of these avalanches failed on drifted features with two below treeline on non-drifted slopes.  Looking around leeward features in Southeast Mountains did not see any other recent avalanches.  While driving pavement in afternoon, I spotted a couple very small loose avalanche on Gothic Mountain coming out of steep, rocky southerly features.
Weather: A cold early morning in the canyon quickly gave way to warm, sunny weather. Above treeline, W and NW winds blew at consistent moderate speeds with high gusts.

Snowpack:  Toured up and over Cement Mountain.  This is a relatively shallow snowpack area as it is in the Southeast Mountains and receives less snow volume than other areas in Southeast Mountains due to its location.

Below 10k, the snowpack consisted of generally 80 cms of thin crust/ facet combos. When HS was less than around 80 cm, ski pen was to the ground. As we increased in elevation to about 10K-ish, HS increased above 80 cms to around 100cm and the snowpack thankfully began to support the weight of a skier while breaking trail. We didn’t get any alarming signs of instability as we were making our way up through the trees on N aspects below treeline.

As we got near and above treeline, we continued to see W and N winds transport snow onto leeward start zones. A snowpit test on a slightly windloaded, NE-facing aspect near treeline produced moderate propagating results. We did get one large rumbling collapse while traveling on ridgeline, adjacent to the NE facing start zones. The collapse did not produce any cracks but it was loud enough to hear over the blustering winds. Much of the avalanche paths we traveled above had already slid during the last 3 weeks. Most of the bed surfaces had not refilled enough to slide again. We chose not to ski any of the slopes that had previously avalanched because of the low quality of skiing, not necessarily avalanche hazard.  Briefly touched a few below treeline sunny slopes that were moist but not wet enough to cause Wet Loose concerns due to winds keeping surfaces relatively cool.

Photos:

Date of Observation: 02/22/2021
Name: Cosmo Langsfeld

Zone: Southeast Mountains
Location: Middle cement creek
Aspect: East
Elevation: ~10k’

Avalanches: Small, fresh looking crown on same path that slid across cement creek road a little while back. Photo from Monday afternoon.

Photos:

Date of Observation: 02/21/2021
Name: jeff banks

Zone: Southeast Mountains
Location: gothic road at S curve
Aspect: South East
Elevation: 9550

Avalanches: none
Weather: howling & cold all day, heavy transport drifting upslope from NE and loading top of California bowl (transport from the bottom) forming a new ~3ft cornice @ 10,800 on the blunt ridge in a break in the trees
Snowpack: 1 medium whumpf in heavily ski tracked conifer forest above weather station plot meadow @ 10,700

Propagation on PST X 2 on Gothic Road SE @ 9550
45/100 END down 70cm Failed on 4mm FC F hard 20cm above ground interface w/ MFCR Knife to 1F slab HS 100cm
40/110 END Same-Same

Date of Observation: 02/22/2021
Name: Frank Stern

Zone: Southeast Mountains
Location: Snodgrass/Gothic
Aspect: North East, East
Elevation: 9,500-10,500

Avalanches: One looks like a natural release today, crown maybe 100′ long, east and below California bowl, D2. One or two (might have all happened at once in 2nd bowl, combined width 500′ or so, ran 700-800 feet. One on lower East of Gothic.   CBAC Note: Some of these may have run earlier in the cycle (ob A, ob B).  Hard to keep track of all the crowns on Snodgrass.
Weather: Sunny
Snowpack: Some wind and sun crust, mostly soft.

Date of Observation: 02/21/2021
Name: Andrew Breibart

Zone: Southeast Mountains
Location: Washington Gulch-Coneys
Aspect: North East, East
Elevation: BTL

Avalanches: From Coney’s ridge line observed an avalanche on Schuylkill. Appears to be a a wind slab with a D2 on damage scale. NTL on East aspect. photo attached and didn’t see it any photos from 2/13-2/15. Maybe this occurred between 2/19-2/21.   CBAC note: this slide was first observed 2/15, but documented from a poor vantage point.
Weather: Moderate winds with strong gusts. Lots of blowing snow especially in the valley bottom. See dune photo. Negligible snow was being transported along the ridge line.
Snowpack: Measured snowpack in an open area below the trees down gradient of first bowl: snow depth ranged between 140 and 155 cm.
Ridge top: ski pen- 4 inches and boot pen was 9 inches. HS ranged between 135 and 150 cm.
new snow was around 2 inches.
leeward side of ridge line had new snow between 4 to 6 inches.

Photos: