Zone: Northwest Mountains Route Description: Upper Slate to Paradise Divide and Cinnamon Mtn, traveling mostly on southerly aspects and ridgelines.
Observed avalanche activity: Yes Avalanches: Nothing new in this area since my visit to Baldy two days ago, except for the Augusta slide reported by Kinler. New vantage of more crowns from last week’s winds and older. Weather: Partly cloudy, light to moderate southwest winds, no snow transport. Snowpack: Snow surfaces are faceted and weak below treeline, with thin sun crusts in the upper few inches on sunbaked slopes. Where recent drifting overlaps with these layers, I easily triggered shooting cracks and collapses up to 6″ deep. These were harmless in size and fairly isolated, but a good indicator of how the current surface will be a problem with future loading. Above treeline, the snow surface is heavily worked by winds, ranging from hard sastrugi to hard wind board to hard wind slab that produce no signs of instability. I did not experience any collapses or signs of instability on basal weak layers either.
Photos:
Shooting cracks and collapses where recent drifting overlapped with weak facets on BTL southerlies.
A recent slab avalanche on a southwest facing slope. Looked like a wind slab from afar.
Persistent slab crown above Yule Pass from sometime last week.
An older slide in the west bowl of Baldy
Better vantage of the peak to creek slides on Purple (previously documented).
Estimated avalanche date: 12/14/2022 Number of Avalanches: 1
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide) Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: NE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R2 small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Date estimated. Above Yule Pass, Purple Mtn side.
Zone: Northwest Mountains Route Description: Various Aspects, primarily between 10,800ft and 11,800ft.
Observed avalanche activity: No
Snowpack: Informal observation, just traveling through the terrain.
Gladed westerly facing slopes around 30 degrees produced several shooting cracks. Skis were punching through the slab on hard turns.
ESE-facing slopes gave no obvious signs of instability with snowmobiles jumping and bouncing around on low 30-degree terrain next to steeper slopes. Felt really easy to get sucked into more aggressive terrain given the lack of obvious signs of instability.
Estimated avalanche date: 12/18/2022 Number of Avalanches: 1
Location
Location: Poverty Gulch (Pittsburg, Augusta, Baxter Basin) Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: E
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R2 small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Date of Observation: 12/17/2022 Name: Scott Toepfer
Zone: Northwest Mountains Route Description: Yule Creek
Observed avalanche activity: Yes Avalanches: N’ly aspect off the ‘Nipple’ south of Ant up Yule Creek. Big. Estimate crown was 15-20 feet, whole face below the summit cliff band pulled out to ground, wall to wall. We did not notice it yesterday, (and we were looking up that way a lot) or this morning, but we may not have noticed this morning while we trying to stay warm. I’m going to classify it as HSNR4D3G Not sure starting elevation or other dimensions but the crown was visible from a long ways away. I’d bet money it hit valley floor. Sorry, no fotos.
Estimated avalanche date: 12/17/2022 Number of Avalanches: 1
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide) Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: N
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R4 large Destructive Size: D3 – could destroy a car, wood-frame house, or snap trees Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Via CAIC ob. https://classic.avalanche.state.co.us/caic/obs/obs_report.php?obs_id=72943
Observed avalanche activity: Yes Avalanches: A small, D1 avalanche slide in the 2nd Climax Chute. Weather: Sunny, no wind, 10 degrees F. Snowpack: Unstable snowpack, with a persistent slab problem on all West to East aspects at all elevations and a wind slap problem on most higher elevation SW to NE aspects.
Zone: Southeast Mountains Route Description: Snowmobiled out West Brush and skied on the southwest side of Teocalli up to 12,200′.
Observed avalanche activity: Yes Avalanches: A handful of recent slab avalanches up to D2 in size on the eastern half of the compass. There’s been so much wind in this area that crowns are a bit harder to decipher (wind slab vs. persistent slab) and put an age on it. I’m only documenting the slides that look to have fairly recent debris; there were a few others that are either older or just blown in now. Weather: Cold temps this morning, pleasant this afternoon in the sun. Calm winds. Snowpack: We noted two collapses while snowmobiling in the flats at valley bottom, radiating about 30 to 50 feet. Slabs there are about 18″, soft and faceting. On southwest terrain, there were no persistent slab concerns: now from the past few weeks is shallow and faceting now (1-2mm), capped by various thin melt freeze or wind crusts in some areas, without any underlying old snow. There were a few cross-loaded gullies where we managed for recent shallow drifts (both hard and soft), but they were unreactive to our ski cuts in steep terrain. Winds did a number on the alpine in this area; some of the problematic terrain is heavily eroded now, other terrain saw loading. Surfaces N/ATL are all worked by the wind.
Photos:
Recent persistent slab on Mt. Baldy (SE aspect)
An older crown on the left (first observed 12/9), and a recent one on the right. White Mtn.
Recent slab activity above West Brush Creek.
Recent slab activity above West Brush Creek.
Recent slab activity above West Brush Creek.
Southwest facing terrain. Might be thin but at least it didn’t have a persistent slab on it.
Estimated avalanche date: 12/14/2022 Number of Avalanches: 1
Location
Location: Mount Baldy Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: SE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R2 small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Nirvana Bowl. Failure date estimated.
Estimated avalanche date: 12/15/2022 Number of Avalanches: 1
Location
Location: West Brush Creek Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: SE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R1 very small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Estimated avalanche date: 12/14/2022 Number of Avalanches: 2
Location
Location: West Brush Creek Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: E
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Unknown
Size
Relative Size: R1 very small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Small rollovers near valley bottom. Failure date estimated.
Relative Size: R1 very small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Birthday Bowl. Failure date estimated.
Estimated avalanche date: 12/14/2022 Number of Avalanches: 1
Location
Location: Mount Axtell Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: NE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R1 very small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
The weekly snowpack summary is here. While some areas in the Northwest Mountains received more than a few inches of new snow, the main story this week was clear skies, cold temps, and consistent wind transport and pressing. Accompanying this wind loading were some impressive natural avalanches and a lingering wind slab problem as we move into the weekend.
Zone: Northwest Mountains Route Description: Viewed from Mt. Baldy
Observed avalanche activity: Yes Avalanches: Adding more avalanches to the previous observation. Ruby, Afley, Peeler Peak, Treasury, and Gothic. The Gothic slide may have run today, the others ran sometime in the past 4 days.
Photos:
This slide off the west side of Gothic may have run today.
Peeler Peak. Broad avalanche across north facing bowl. Couldn’t see runout.
Estimated avalanche date: 12/16/2022 Number of Avalanches: 1
Location
Location: Gothic Mountain Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: W
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R1 very small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: I did not see this crown mid-morning when we rode by it, but I saw it around sunset. Maybe I missed it this morning, or maybe it ran today.
Estimated avalanche date: 12/15/2022 Number of Avalanches: 1
Location
Location: Oh-Be-Joyful Basin Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: N
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R3 medium Destructive Size: D3 – could destroy a car, wood-frame house, or snap trees Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Peeler Peak, middle bowl below summit. Could only see the start zone (which failed broadly), so size is best guess, as is failure date.
Estimated avalanche date: 12/13/2022 Number of Avalanches: 2
Location
Location: Oh-Be-Joyful Basin Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: NE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R1 very small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Afley NE face. Size and failure date estimated.
Estimated avalanche date: 12/14/2022 Number of Avalanches: 1
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide) Location Specific: Start Zone Elevation: Aspect: E
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Unknown
Size
Relative Size: R2 small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Treasury Rock Creek. Repeat offender, verified with photos that it is a different crown that the one observed 12/7
Zone: Northwest Mountains Route Description: Mt. Baldy, traveling primarily on south and southeast aspects to 12,400′
Observed avalanche activity: Yes Avalanches: A handful of destructive persistent slabs ran in the past few days. Most notable includes a pair of very large hard slabs (D3) on Purple Ridge that ran over Purple Bench and reached the Slate River, ~2100 vertical, and several others in the ~D2-D3 range off or Ruby Peak, Peeler Peak, Schuylkill Peak, Bichmond, and Gothic. All fit the same distribution pattern as previous cycles. Today’s observed slides were all on W to N to E starting near or above treeline. Hard to say exactly which days they ran on, some crowns looked very fresh (24-36 hours), others were more drifted in and probably ran during the peak of the last storm (~12/13) Weather: Cold, clear, light northerly winds this afternoon on Baldy. I could see notable transport in the Southeast Mountains this morning, especially near Whiterock. Snowpack: Apart from one collapse in a relatively thin area (from wind erosion), we saw no signs of instability under foot. Test results on a windloaded SE facing slope near treeline produced propagating results (PST 47/137 END) under a 130 cm hard slab (up to pencil hard). The weak layer is showing substantial improvements compared to the start of the month; It was 4F+ and rounding. Still an ugly structure and now scary consequences, but on an improving trend.
Photos:
Several destructive slides on Purple Ridge, two of which ran over Purple Bench towards the Slate River (out of site)
Closer view of the same slides.
A long-running persistent slab on Schuylkill Peak
The newest looking crown in the Ruby Range. My guess is it ran last night or this morning before we spotted it around 10 a.m.
Andy is unhappy about this structure. And that I made him dig to the ground while I ate lunch and pretended to look at natural avalanches.
Estimated avalanche date: 12/15/2022 Number of Avalanches: 1
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide) Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: E
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R3 medium Destructive Size: D3 – could destroy a car, wood-frame house, or snap trees Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Purple Ridge, nuclear chute. Ran over the bench and into Slate River.
Estimated avalanche date: 12/14/2022 Number of Avalanches: 1
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide) Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: NE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R3 medium Destructive Size: D3 – could destroy a car, wood-frame house, or snap trees Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet): 2100
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Purple Ridge, Penthouse. Ran over Purple Bench to Slate River.
Estimated avalanche date: 12/16/2022 Number of Avalanches: 1
Location
Location: Poverty Gulch (Pittsburg, Augusta, Baxter Basin) Location Specific: Start Zone Elevation: ATL: Above Tree Line Aspect: E
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R2 small Destructive Size: D2 – could bury, injure, or kill a person Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: Near Angel Pass. Very fresh looking crown, guessing it ran last night or this morning.
Estimated avalanche date: 12/14/2022 Number of Avalanches: 1
Location
Location: Schuylkill Ridge Location Specific: Start Zone Elevation: NTL: Near Tree Line Aspect: NE
Characteristics
Trigger: Natural Trigger modifier: Type: Hard Slab Failure Plane: Old snow
Size
Relative Size: R3 medium Destructive Size: D3 – could destroy a car, wood-frame house, or snap trees Avg. crown height (inches): Avg. width (feet): Avg. vertical run (feet):
Involvements
# of people caught: # of partial burials: # of full burials:
Additional comments: “The President” path on Schuylkill Peak. Ran fairly far into the runout, a few hundred vertical feet short of creek bottom near Pittsburg.