Regional Conditions for Northern Madison

Looking up into the gully from the debris of the cornice triggered avalanche. Photo: M. Sebren

Looking north at the crown of the cornice triggered slide in the Hourglass, north of Bridger Bowl. Photo: M. Sebren

The avalanche crown (3-4 feet deep) is visible near the ridgeline. Photo: BBSP

Photo is from the ridgeline. This avalanche was triggered midday Wednesday (2/26) north of Bridger Bowl ski above Wolverine Bowl.  The slide is east facing and broke 3-4 feet deep from a natural cornice fall. It broke 4-5 feet wide mid-slope and broke on the facets near the bottom of the snowpack. No one was caught. Photo: BBSP

Skiers saw this 2-4' deep natural crown on Sunday 2/23/20. Photo: from IG @skishot

"Very large and destructive deep slab just north of emigrant peak on a east-facing aspect. The debris likely ran over 1000 vertical feet and stopped towards the bottom right of the image. We think the smaller slide on the far right was triggered as a secondary slide as a result." Photo: T. Papritz

"Very large and destructive deep slab just north of emigrant peak on a east-facing aspect. The debris likely ran over 1000 vertical feet and stopped towards the bottom right of the image. We think the smaller slide on the far right was triggered as a secondary slide as a result." Photo: T. Papritz

An image of the 4 crown and location of debris.

This crown was the one to the furthest looker's left of the bowl. Photo: GNFAC

These trees were bent over from repeated avalanches in this bowl. Photo: GNFAC

The deepest part of the crown was estimated to be 10-12' deep. It was a steep and heavily wind-loaded with a rocky starting zone.  Photo: GNFAC

The avalanche was powerful and put debris far down the slope along the flat bench. Photo: GNFAC

These 4 avalanches seem to have run at the same time (estimated 15 or 16 February) although the crown does not connect them, but the weak layer of depth hoar surely does. Slides 1 and 2 merged into the huge debris field. Photo: GNFAC

The end of the runout is marked with the arrow. Photo: GNFAC

I measured the Alpha Angle (angle from crown to toe of debris) at 16 degrees. This is a very low angle that signifies the avalanche ran about as far as it ever could based on the size of the path. I took 5 measurements using 2 inclinometers to make sure this was correct. Photo: GNFAC

The uphill branches on this stand of trees was freshly limbed up to 15' high. Photo: GNFAC

From IG #gnfacobs post: "An avalanche from early Tuesday (02/18) morning caused by a natural cornice fall. Note the step down partway down the path. ENE @ 9700. Ran 1300’." Photo: A. Whitmore

Debris from an avalanche that broke the weekend of 2/14-2/15 on the north face of Mt. Blackmore in Hyalite. Photo taken 2/21/20: GNFAC

Natural avalanches on Wilson Peak shot from Beehive/Bear ridgeline. Likely broke on Tuesday, Feb 18th.

Photo: T. Grande

Natural avalanches on Wilson Peak. Likely broke on Tuesday, Feb 18th.

Photo: B. Rode

Multiple crowns on Wilson seen from moonlight basin, pictures aren’t good quality and hard to see the crown. Not sure how big the crowns are, but looked like a deep slab. Photo: Tommy Saulnier

"I had been riding trees most of the day down low and moved up to about mile marker 10 later in the day. Did a side hill through open trees and stopped on top of this slope. Watched it all propagate and slide below me." Photo: anonymous

From message: "Went out on a recon to Buck Ridge today. Knew the dangers and avoided riding open slopes. I had been riding trees most of the day down low and moved up to about mile marker 10 later in the day. Did a side hill through open trees and stopped on top of this slope. Watched it all propagate and slide below me." Photo: anonymous

"...picture is a close up of the avalanche on the ridge between Elephant and Blackmore on a south aspect. This one was the largest and the most fresh. All avalanches appeared to be naturally triggered from wind loading." Photo: T. Chingas

"looking at Alex Lowe Peak from the west ridge of Elephant. There were 5 avalanches clearly visible. I highlighted the crowns/debris paths with red." Photo: T. Chingas

"Toured up Blackmore today... Also saw the wheeler mountain avalanches from a few days ago." Photo: Mike Murray

"Toured up Blackmore today, we had shooting cracks under our feet along the north east ridge line." Photo: Mike Murray

"We came across the debris of a significant slide in one of the steeper lines just north of Wolverine bowl today. There was zero new fallen snow on the debris so it happened sometime this morning before 11:30 a.m. and after the snowfall stopped last night. The multiple crowns looked to be 3-5 feet tall and a large tree has been jammed into the tube ride chute. The toe of the debris is all the way down into the creek at the base of Wolverine. It's possible a large cornice broke off at the ridgeline but we couldn't get eyes on the actual start of the slide. We skinned up and down the debris pile twice while in search mode at around 12:30 but did not pick up a signal. We did not investigate above the pinch of the chute and into the upper part of the slide. The debris pile is quite deep with some damaged trees. We did 6 lines off the ramp over the weekend and did not see any other avalanche activity but obviously some significant wind loading." Photo: Ray K

"We came across the debris of a significant slide in one of the steeper lines just north of Wolverine bowl today. There was zero new fallen snow on the debris so it happened sometime this morning before 11:30 a.m. and after the snowfall stopped last night. The multiple crowns looked to be 3-5 feet tall and a large tree has been jammed into the tube ride chute. The toe of the debris is all the way down into the creek at the base of Wolverine. It's possible a large cornice broke off at the ridgeline but we couldn't get eyes on the actual start of the slide. We skinned up and down the debris pile twice while in search mode at around 12:30 but did not pick up a signal. We did not investigate above the pinch of the chute and into the upper part of the slide. The debris pile is quite deep with some damaged trees. We did 6 lines off the ramp over the weekend and did not see any other avalanche activity but obviously some significant wind loading." Photo: Ray K

"We came across the debris of a significant slide in one of the steeper lines just north of Wolverine bowl today. There was zero new fallen snow on the debris so it happened sometime this morning before 11:30 a.m. and after the snowfall stopped last night. The multiple crowns looked to be 3-5 feet tall and a large tree has been jammed into the tube ride chute. The toe of the debris is all the way down into the creek at the base of Wolverine. It's possible a large cornice broke off at the ridgeline but we couldn't get eyes on the actual start of the slide. We skinned up and down the debris pile twice while in search mode at around 12:30 but did not pick up a signal. We did not investigate above the pinch of the chute and into the upper part of the slide. The debris pile is quite deep with some damaged trees. We did 6 lines off the ramp over the weekend and did not see any other avalanche activity but obviously some significant wind loading." Photo: Ray K

We came across the debris of a significant slide in one of the steeper lines just north of Wolverine bowl today. There was zero new fallen snow on the debris so it happened sometime this morning before 11:30 a.m. and after the snowfall stopped last night. The multiple crowns looked to be 3-5 feet tall and a large tree has been jammed into the tube ride chute. The toe of the debris is all the way down into the creek at the base of Wolverine. It's possible a large cornice broke off at the ridgeline but we couldn't get eyes on the actual start of the slide. We skinned up and down the debris pile twice while in search mode at around 12:30 but did not pick up a signal. We did not investigate above the pinch of the chute and into the upper part of the slide. The debris pile is quite deep with some damaged trees. We did 6 lines off the ramp over the weekend and did not see any other avalanche activity but obviously some significant wind loading. Photo: Ray K

"We came across the debris of a significant slide in one of the steeper lines just north of Wolverine bowl today. There was zero new fallen snow on the debris so it happened sometime this morning before 11:30 a.m. and after the snowfall stopped last night. The multiple crowns looked to be 3-5 feet tall and a large tree has been jammed into the tube ride chute. The toe of the debris is all the way down into the creek at the base of Wolverine. It's possible a large cornice broke off at the ridgeline but we couldn't get eyes on the actual start of the slide. We skinned up and down the debris pile twice while in search mode at around 12:30 but did not pick up a signal. We did not investigate above the pinch of the chute and into the upper part of the slide. The debris pile is quite deep with some damaged trees. We did 6 lines off the ramp over the weekend and did not see any other avalanche activity but obviously some significant wind loading." Photo: Ray K

"Slide occurred on north aspect of Mt Blackmore at 9200ft. Photo provides close-up view and width of crown." Photo: Laura Ippolito

"Slide occurred on north aspect of Mt Blackmore at 9200ft. Photo was taken at the end of the runout." Photo: Laura Ippolito

"Slide occurred north northwest aspect of Mt Blackmore at 9400ft in a narrow meadow. This provides width of slide." Photo: Laura Ippolito

"Slide occurred north northwest aspect of Mt Blackmore at 9400ft in a narrow meadow. Close-up view of an approximate 8" crown." Photo" L. Ippolito

Photo of the Divide Basin avalanche that was likely triggered by a cornice fall on Friday, Feb 14. Photo: Nick Truax

Photo of the Divide Basin avalanche that was likely triggered by a cornice fall on Friday, Feb 14. Photo: Nick Truax

From an observation, "R3-4 D2 avalanche that failed at the ground observed from the Trail Creek Rd. Looked to be several hundred feet wide, couldn’t see the debris, but crown went through lots of trees." Photo: Chris Cullaz

From an observation, "R3-4 D2 avalanche that failed at the ground observed from the Trail Creek Rd. Looked to be several hundred feet wide, couldn’t see the debris, but crown went through lots of trees." Photo: Chris Cullaz