Slide at Abasin

[truth]

By David Montero And Joe Garner, Rocky Mountain News
May 21, 2005

KEYSTONE - A 53-year-old Boulder man died in an avalanche at the Arapahoe Basin ski area Friday morning - the first such casualty within the boundaries of a marked ski run in 30 years.

David Conway was skiing on an expert run when the avalanche began and he became trapped in the sliding snow, rescuers said.


The Summit County Coroner's Office said Conway owned a construction company.

Rescuers said there might be a second person buried under the slide and a search effort will begin today at first light, according to Glen Kraatz, of the Summit County Rescue Group.

But, said Alan Henceroth, director of mountain operations at Arapahoe Basin, "we have no other reports of missing parties at this time."

Kraatz said the search had to be suspended around 1:30 p.m. because the situation on the mountain had grown too dangerous due to warm weather and unstable snow.

The avalanche happened around 10:30 a.m. on the Pallavicini Trail. The slide covered 800 vertical feet and was about 200 feet wide, hugging the side of the ski run and ripping through the tall trees.

Derek Bell, a 30-year-old snowboarder from Castle Rock, said he and a friend arrived minutes after the avalanche occurred. He saw paramedics bring the victim down the mountain and begin administering CPR. Conway was declared dead about noon.

"I was going to take a picture of the whole thing, but that's not an image I wanted in my mind," Bell said. "I just said a quick prayer."

His friend, 31-year-old Damien Bramlage, said a buddy of his snowboarded the area the other day and thought the snow felt "funny."

Bramlage said the snow was heavy and wet - prime for avalanches.

"There's an avalanche in every chute," he said, pointing to creases in the mountains where strips of snow were bordered by rocks.

Both said it was a dramatic scene seeing the Flight for Life helicopter land on the slope while about a half-dozen rescuers prodded the slope for other potential victims.

Henceroth said the trail affected by the avalanche was inspected by crews earlier in the day and explosives were used to prevent a slide.

The trail will be closed today while the ski resort conducts an investigation, he said. The Summit County Sheriff's Department also is investigating.

Mike Schmitt, Summit County deputy coroner and a rescue volunteer, said he was "very surprised" the avalanche happened within the bounds of a ski run.

But this is the time of year when skiers need to be especially cautious, experts said.

The combination of summerlike temperatures along the Front Range and the snow cover at Arapahoe Basin not freezing Thursday night led to the instability, said Knox Williams, director of the Colorado Avalanche Information Center in Boulder.

"That snow was getting very weak because the melt was going on inside the snowpack," he said.

This time of year, the snowpack actually is about 60 percent air and 40 percent ice and water, he said.

Williams said the late-season snow cover at Arapahoe Basin, which sometimes stays open until the Fourth of July, "usually just sits there and doesn't avalanche."

Before Friday's tragedy, the last avalanche fatality within the boundaries of a ski run occurred Jan. 9, 1975, at Crested Butte, Williams said. The victim, Robert Hewit, 23, was tree-skiing between two groomed runs, Williams said. "Everything was open," he said. "The skier absolutely was not at fault."

Although a friend skiing with Hewit and other skiers on a chairlift notified ski patrollers as quickly as they could, Hewit could not be saved.

Hewit triggered the slide above him, which is almost always the case, Williams said.

"The powder between the groomed runs was almost like a back-country situation," Williams said. "If you can ski through trees and make normal turns, then the trees are not close enough to prevent an avalanche."

Friday's death was the fifth avalanche death this year in Colorado. Two of every three avalanche deaths are the result of suffocation from snow encasing the victim.

"If the snow packs in around your mouth and nose, you could suffocate within 10 minutes, easily," Williams said.

"Snow is heavier than anyone would expect," he said. "If a person is buried under one foot of avalanche snow, it's unlikely a person could dig himself out.

If conditions permit, staff members of the Colorado Avalanche Information Center will try to investigate in the slide area today, Williams said.

Arapahoe Basin officials said that while the avalanche-affected trail will be closed, the resort will remain open.

Typically, the ski area is one of the last resorts to close. Its last day is scheduled for June 5.

"The ski patrol and management have 20 or 30 years of dealing with this snow cover," Williams said of the ski area. "They are very professional."

Fatal avalanches this season

• Jan. 3:A backcountry skier on a run known as the "Flume of Doom" on Soda Mountain near Buffalo Pass was buried in an avalanche. Michael Gebhart, 26, of Steamboat Springs was wearing an avalanche beacon and was dug out in eight to 10 minutes but he could not be revived.

• March 6: A participant in an avalanche awareness class near the Aspen Highlands ski area was killed by a snowslide. John William Jensen, 32, was the only member of the group hit by the slide.

• March 24:Two climbers on Quandary Peak in Summit County were caught in a slide on the south side of the mountain. One man survived while his friend, Jeff Uppendahl, 26, of Colorado Springs, was buried and killed.

• April 1: A 27-year-old Boulder man was buried and killed in an avalanche on Grand Mesa. Jared Wood was backcountry skiing with a Grand Junction friend when a slide 50 yards wide and three feet thick swept over him.Sources: Colorado Avalanche Information Center, Rocky Mountain News Archives And The Journal News Of Westchester County, Ny.

[Phatstix]

By David Montero And Joe Garner, Rocky Mountain News
May 21, 2005
"This time of year, the snowpack actually is about 60 percent air and 40 percent ice and water, he said".

Snow Gliding: Typical glide speeds are in the range of 1 to 100 mm/day. It occurs on slopes when the snowpack slips at an interface (such as an ice layer) or over the ground. Snow gliding is important in the formations of slab avalanches that involve the full depth of the snowpack. A number of conditions must exist before gliding takes place:
1. The interface must be fairly smooth. 2. The temps. at the interface or bottom of the snowpack must be at 0 degrees C (get a digital thermometer); this gurantees free water will exist at the interface. 3. The slope angle must be 15 degrees for roughness typical of alpine ground cover.
Snow gliding at the ground is thought to be the result of creep of snow over the roughness features there. It is also know that the rate of gliding is very sensititve to the amount of water present at and near the ground. Increasing amounts of water, usually caused by rainfall of heavy snow melt during warm weather, cause reduced friction at the snow/ground interface by drowning small roughness features, hence, increasing the glide rate. In addition, snow stiffness (vicosity) decreases with increasing water content, making creep over the ground rougness features easier (warm taffy). Once excess water drains away, the glider rate slows. (taken from the Avalanche Handbook).

[truth]

ARAPAHOE BASIN — A continued search for possible other avalanche victims was called off early this morning as warm temperatures continued to make the snowpack dangerous.

Dillon District Ranger Rick Newton of the U.S. Forest Service and others went to the top of the slide at the top of the Pallavicini area of the mountain to investigate where the slide started.

There were no reports of missing people, which may mean David Conway, 53, of Boulder could be the only victim.

This report will be updated. The following story still stands as a report of Friday's events.

•••

A 53-year-old Boulder man died Friday morning after he was caught in an avalanche while skiing the expert Pallavicini section of the Arapahoe Basin Ski Area.

David Conway was pronounced dead at noon Friday, about an hour and a half after A-Basin ski patrollers found him in a debris field at the bottom of the slide.

Summit County Coroner Joanne Richardson has not released a cause of death, pending further investigation. She said he owned his own construction company.

Just before 10:30 a.m. Friday, the 300-foot slide fractured just above the First Alley trail, skier’s left of the Pallavicini Lift.

The snow cascaded about 1,000 feet through a cluster of trees before stopping in a heaping pile of debris.

A-Basin ski patrollers responded immediately and quickly found Conway, who was slightly exposed, according to Summit Rescue Group site commander Glen Kraatz.

Patrollers immediately administered emergency care, then Conway was taken to the mountain’s base-area first-aid hut, where staff from St. Anthony Flight For Life and the Summit County Ambulance Service continued life-saving efforts.

It is not known whether the Conway was alive when rescuers reached him.

He was found in the debris field at the edge of the trees and although his exact path isn’t known, someone’s chance of survival is usually worse if he or she is carried through a heavily gladed area, Kraatz said.

“You’ve got an opportunity for a person to be washed into trees, rocks and so on,” he said.

As of about 3:30 p.m. Friday, the ski area had not received any other reports of missing skiers or snowboarders, director of mountain operations Alan Henceroth said during an afternoon press conference.

“This was an unlikely event that hasn’t happened in the time I’ve been here,” said Henceroth, who’s been at the mountain 22 years. “We’ve closed that area to prevent further incidents.”

The Colorado Avalanche Information Center reported this was the first avalanche fatality at a ski area since Jan 9, 1975.

The mountain is still investigating whether the man was part of a larger group of skiers and whether the avalanche was naturally or skier-triggered, but exact details are elusive because there are no known witnesses to the slide, Henceroth said.

About half a dozen Summit Rescue Group searchers joined 15 ski patrollers and three avalanche dog teams to comb the 50- to 150-foot-wide debris field at the bottom of the slide.

They formed a shoulder-to-shoulder probe line, searching for any signs of an avalanche path down which a victim could have been swept — skis, ski poles, gloves, even blood, Kraatz said.

“You have to err on the side of maybe,” Kraatz said. “We were definitely up there with the feeling that we were doing everything we can if another person is caught.”

Conditions were wet, heavy snow that was getting sloppier as the thermometer rose.

“There were chunks up there the size of Volkswagens,” he said, “there were chunks the size of footballs and basketballs.”

The search was called off at about 12:45 p.m., when A-Basin officials determined the conditions posed too much of an avalanche risk to rescuers — specifically because of the warm weather.

“You’re getting to a situation right now, where you could have a natural slide because of the heat,” Kraatz said at about 2 p.m.

The Pallavicini area was open for skiers Friday morning and staff members had been on the run before the avalanche, Henceroth said.

The Pallavicini chairlift was closed immediately following the slide, along with the expert East Wall terrain on the other side of the ski area.

The remainder of the mountain was kept open.

Most skiers seemed unaffected by the avalanche as business went on as usual at the Exhibition Lift, although some were slightly shaken.
Westminster resident John Stevens was about three-quarters of the way down the First Alley trail when he heard the avalanche.

“I didn’t realize what happened until I saw it,” Stevens said. “At the most, I was 30 seconds ahead of that avalanche.”

The Pallavicini lift and trails will be closed to the public on Saturday, but the remainder of the mountain will be open. The Nocturnal Tomatoes are still set to play from 1-4 p.m. in a free outdoor show.

The search will be resumed as soon as conditions allow.
Representatives from the Summit County Sheriff’s Office, Lake Dillon Fire Authority and the U.S. Forest Service were all on-scene throughout the morning and afternoon.

Nicole Formosa can be reached at (970) 668-3998, ext. 229, or at nformosa@summitdaily.com

[Mtn Man]

Any update on the search today?


B)

[SIIHP]

Any update on the search today?


B)

It was too dangerous to look much for people/ do body recovery if anyone else was there. Never really froze last night. Bro says they set off explosives and the entire Pali face came down. Guess that side of the mountain is bare...

[jpcski]

Their website says that Pali and the terrain it serves are closed for the season.

[FigureEleven]

Just saw some footage of the ski patrol blasting the hangfire, and it was pretty impressive. They knocked a lot more snow off, and it sure stacks up deep down in the choke and on the debris field.

On the good side, blasting more of the bowl down on to the old debris indicates that they must be fairly certain there was no one else buried in the initial slide. Having only one person caught in a slide in the area was very lucky IMHO.

[truth]

On the good side, blasting more of the bowl down on to the old debris indicates that they must be fairly certain there was no one else buried in the initial slide.

[SIIHP]

On the good side, blasting more of the bowl down on to the old debris indicates that they must be fairly certain there was no one else buried in the initial slide. Having only one person caught in a slide in the area was very lucky IMHO.

Unfortuantely no. They are going off no missing person reports to figure that out. They couldn't search this morning really because the danger was still high. If there is someone, they are now deeper and will be found later.

[FigureEleven]

Unfortuantely no. They are going off no missing person reports to figure that out. They couldn't search this morning really because the danger was still high. If there is someone, they are now deeper and will be found later.

Wow, thats unfortunate. I thought they got a probe line through most of it yesterday.

[AltaPowderDaze]

this is a great reminder for all of us that "skier compaction" doesn't make a snowpack 'safer' or more stable.

it actually does in many cases for many reasons. wet slabs are a different beast than the usual dry ones. a perfectly good bond to a crust or weak layer is degraded to where it can no longer hold its own weight.

Re: Glide

Could the runoff / melt caused enough rotting (SheRa's info) of the snowpack below the rollover (pic of fracture) that the top could no longer support the hanging weight of the slope? Would there have been any visible warning like in a winter glide sceario as this seems to indicate that it just ripped out? I doubt it would have gone unnnoticed if there was a fissure forming where that fracture is.

i think you're right. it doesn't appear to be a glide plus the caic is saying that the slide was skier triggered. all the info just seems inconsistent with a glide.

here's what the ciac has to say:

The Avalanche
The avalanche has been classified as a WS-AS-2-O/G. It released at treeline with the initial fracture of 1.5 to 2 feet deep, but as the wet slab moved down the mountain in places it plowed to the ground releasing snow about 4 feet in depth. The debris was wet, heavy, and deep. Rescuers said that in places their 10-foot probes could not touch the ground. The slide has been estimated at about 250 across and running about 500 vertical feet on the north-facing slope.

More here: http://geosurvey.state.co.us/avalanc...=44#AB05202005


my sympathy to friends, family and those who were there.

[pointemstraight]

RIP, Dude.

Fatal avalanches this season

• Jan. 3:A backcountry skier on a run known as the "Flume of Doom" on Soda Mountain near Buffalo Pass was buried in an avalanche. Michael Gebhart, 26, of Steamboat Springs was wearing an avalanche beacon and was dug out in eight to 10 minutes but he could not be revived.

Stuff like this gives me the heebie-jeebies as well - this dude was dug out in 8 or 10 minutes and still didn't make it. Even when the rescue attempts are quick, it's never a garantee....

[SIIHP]

Wow, thats unfortunate. I thought they got a probe line through most of it yesterday.

They tried to get through as much as they could, but had to work fast because of the danger. From what I understand they were spread out working to cover as much as possible as quickly as possible before being called off from the hangfire danger. They were gonna get back at 5 AM and resume, run a more thorough search, but it was too warm and never refroze. They will probably try again tomorrow. But last I heard there were no missing person reports so hopefully they find nothing.

[H20MAN]

Just saw some footage of the ski patrol blasting the hangfire, and it was pretty impressive. They knocked a lot more snow off, and it sure stacks up deep down in the choke and on the debris field.

On the good side, blasting more of the bowl down on to the old debris indicates that they must be fairly certain there was no one else buried in the initial slide. Having only one person caught in a slide in the area was very lucky IMHO.

I was up there again today and that face is demolished sooo scary.

[snowfire]

Well, it was an interesting weekend at the Basin. All of us were pretty much walking around in a daze... no one expected this to happen. Not here, not now. No one really knows what to say. I kept having people come up to me all weekend saying "I'm sorry..." It's just so weird when it happens on your mountain. Makes you realize that no matter what precautions you take, you can't control nature. Pali seems safe, control work is done and it's packed down all season- but in the end, it's just part of a mountain. Really makes you stop and consider your decisions in the past.

The temps only got down to 46 degrees overnight on Sat and 42 on SUnday so we couldn't have a probeline- way too dangerous. The whole of pali face except for 1st bowl slid with bombing though. Fucking incredible. I really can't say anything else about it, but I took some good pictures of the face and the crowns and I'll post them when I get them uploaded in a bit here.

[freshie247]

Thanks for the update SF.

[raddam]

didn't see this link posted here
taken from Telemark Tips forum
pretty huge fracture/slide
RIP

Avy pix here

[truth]

[raddam]

I think that pic was taken after Patrol had blasted the whole face to prevent any other slides. Pretty scary!

[Phatstix]

i think you're right. it doesn't appear to be a glide plus the caic is saying that the slide was skier triggered. all the info just seems inconsistent with a glide.

AltaPowderDaze



Joined: 06 Dec 2004
Posts: 304
Location: Utah Backcountry
Posted: Fri May 20, 2005 8:08 pm Post subject:

--------------------------------------------------------------------------------

i'm curious to know what others think.


as for me, i'm not normally around snow this time of year but my thoughts are that you should take into account the previous weather and snowpack history. if you still have a layered winter snowpack then you should be very concerned with a thin refreeze, especially if you had some decent melt the prior day. if the day is going to get very hot then you shouldn't count on a surface crust holding you past 10:30am. if the snowpack has gone isothermal developed drain channels for the water to flow out, then you can probably push it longer. you should know what type of ground surface you are on during these melt periods. if it's slick rock/grass then you may consider leaving it alone since glides are so unpredictable.
aside from all that, you should check out gary's article in the avy review or his thread on here about crusts. he had an interesting avy story that is worth checking out.
hmm....

[AltaPowderDaze]

AltaPowderDaze


hmm....

your point?

[snowfire]

A couple pics I took:

Slide after blasting



Same pic, the lines approximately distinguish where the separate slides took place: to the right of the pink line was the original slide that caught the dude. To the right of the green line was first bomb and to the right of the blue was second bomb.




part of crown

[Phatstix]

your point?

The point: I'm not trying to be an expert here - I never said that I thought glide was responsible for this - I was more or less throwing it out there. I'm not 100% sure though that ALL the info is inconsistent with glide - skier triggered or otherwise.
Hey, the more we all talk about avi danger the better - Lord know's I can always learn more - That's the POINT really.
Over-

[AltaPowderDaze]

The point: I'm not trying to be an expert here - I never said that I thought glide was responsible for this - I was more or less throwing it out there. I'm not 100% sure though that ALL the info is inconsistent with glide - skier triggered or otherwise.
Hey, the more we all talk about avi danger the better - Lord know's I can always learn more - That's the POINT really.
Over-

i was just wondering why you cut and pasted my post from another site and included the date/time stamp plus my # of posts.

btw, i meant that when all the info is compiled that it doesn't fit the description of a glide as i know it.


glide up close:

[Phatstix]

I just copied and pasted your post because it seemed a bit contradictory to this post (don't get me wrong though, I do see the differences).
Your glide photo is just that - I'm wondering what it looks like at the earliest stages (my earliest comment mentioned 1 to 100 mm/day). Wouldn't a skier at this juncture perpetuate the situation? Would it be noticed during the preliminary stages when it's moving at 1 mm/day?
You seem to know your stuff - my "Hmm" comment and post was really meant to understand what happened that day a little better.
Peace-