Snowbridge Collapse Video

Although avalanche footage is now commonplace, I've never seen video footage of a snowbridge collapse.
Pay close attention at the 0:06 mark:

BTW, I recall noting many years ago that the warning signage at the base of the tram that takes you to this route (with no non-glaciated options) was smaller than at the typical U.S. resort terrain park.

Some Serious Snow Science...

. . . and stability evaluation, for those so inclined:



Fracture character in compression tests from Bruce Jamieson on Vimeo.

Bridger Bowl Wet Slides

Just how long can a persistent weak layer, well, persist?
How about all the way through the spring, even on slopes that have been groomed and all bumped-up!

Scary details in this video:

And in the Gallatin Nat'l Forest avy bulletin:

"Bridger Bowl experienced their most impressive day of wet slab avalanche activity in memory.  Avalanche cycles like this one are rare.  It was only the second time in my 22 years of avalanche work that I’ve seen wet slab activity on this scale.  Yesterday, the ski patrol triggered avalanches with explosives that gouged out groomed runs and road cuts plus put debris up to 20 foot deep in the gullies."

As well as in the picture below from an Unofficial Networks article:

Steve Romeo Incident Report

A noteworthy passage from the official incident report:

"It’s thought that they decided to contour high  across the slope in order to reach the top of their desired ski descent on the southern aspect of the  mountain.  Had they continued switch-backing up along the eastern edge of the avalanche path to reach  the saddle at 10,200’ feet, it’s likely they would have reached that saddle without incident."

A local newspaper article also has some commentary from the park rangers:

The route they chose took them from the edge of an avalanche path into its starting zone, which was the ideal steepness for slides, rangers said.
“They chose to go up a known avalanche path ascending into an avalanche starting zone,” Jenny Lake Ranger Rich Baerwald said.
*****
While Romeo skied radical terrain with elan, he also posted several videos and wrote stories about getting caught in or nearly missed by avalanches.
“I don’t know if he was taking that to heart,” Harder said. “He had more [encounters] in the last few years than I’ve had in my lifetime,” the 30-year Teton veteran said.
“I feel pretty strongly a lot can be learned by this,” Harder said.
*****
Climbing the avalanche path with skins on their skis, Romeo and Onufer initially made the best of hostile country, Baerewald said.
They stuck to the climber’s right, near where cliffs form the edge of the slope.
At an elevation of about 9,700 feet, they made a critical decision.
“They start making their way away from the edge of the avalanche path on into the avalanche track and into the starting zone,” Baerwald said.
Added Harder, “If they were heading to that [pencil-thin] couloir, they probably short-cut over to it.”
An alternative would have been to continue up the right side of the slope, rangers said. This route was less steep and led to a ridge.
“The ridge would have been a safer route,” Baerwald said. Ridge safety is a basic concept, he said.
“The message with regard to route-finding is, it’s super important terrain be considered,” he said.
*****
Once the skiers provoked the slide, nothing could have saved them, rangers said. The avalanche ran a linear mile over cliffs and rocks.
It likely propelled them at speeds between 60 and 80 mph, rangers said. It ripped off one skier’s pack, another’s boot, all four skis.
Searchers found the base layers of one ski ripped from its top plate, its climbing skin still attached.
“The ski was completely delaminated, separated,” Harder said. “Speaking to force, that says a lot right there.”
The chaos likely tore Romeo’s helmet off his pack, and it “sustained a lot of damage,” Harder said.
Romeo had an Avalung pack — a device designed to allow avalanche victims to breathe if buried. Its mouthpiece was deployed, but rangers couldn’t tell whether he had it gripped in his teeth during the slide, they said.
Friends of the two have asked whether avalanche airbags could have saved them, rangers said. Airbags are stowed in backpacks and deploy instantly with the pull of a toggle. They help suspend a skier high in flowing snow and help prevent burial.
But neither skier was really buried, rangers said.
“Chris probably could have sat up,” had he been alert or alive, Harder said. “Steve probably could have wrestled an arm out.
The Teton County Coroner ruled the cause of death was blunt-force trauma.
Buffalo Fork Sub-District Ranger Rick Guerrieri said no gear could have helped.
“One piece of equipment wasn’t going to have any effect on injuries,” he said.
Added Harder, “The best tool they had with them, they weren’t using the most. That was their brain.”
Rangers discounted other skiers’ sentiments about the pair being in “the wrong place at the wrong time.” Such phrases are best reserved for victims of meteorite strikes, they said.
“This [event] had factors in it that [include] decision-making,” Harder said of the avalanche. Rangers are uncertain to what extent the pair took into account the snow and winds.

Avy Research Helps Ice Cream

I've been in touch this month with researchers at the Swiss Institute for Snow and Avalanche, or “SLF” (part of the Swiss Federal Institute for Forest, Snow and Landscape Research), regarding my upcoming article on airbag statistics.
Apparently their research in related matters has quite the range of applications:
http://www.bbc.co.uk/news/technology-17493226

Samples of ice cream have been scanned with an X-ray machine more typically used to study the ice crystals which are key to avalanche formation.
Nestle is hoping to reveal the exact conditions under which ice crystals merge and grow.
When the crystals get big enough they change the texture of ice cream and alter how it feels when it is eaten.
The study of ice crystal formation has been carried out with the help of scientists at the Institute for Snow and Avalanche Research in Davos, Switzerland.

Mt W Conditions Update

March 21 Trip Report:  Mt Washington Four-Ravine Circumnavigation . . . or should that be, March is the new April, or maybe even May, or in some places June.

Yes, although some spots still have nice snow, the possibilities for touring among multiple ravines are pretty slim, or maybe even nonexistent now after yet another day of major melting, and with one more coming up tomorrow.

Full picture set and TR (via captions) here.

... but here are few quick pics ...

Route (clockwise):

Heading on up:

Color coordinating the helmet and skis:

Booting back up after relaying the news up to a waiting Jerimy that, no, it doesn’t go:

Josh in upper Monroe Brook:

And quite a bit further down:

Low, But With Instabilities

Low avy bulletins are usually pretty boring.  But the March 9 Eastern Sierra bulletin discussed numerous weaknesses in the snowpack, despite the Low overall rating.

Avalanche forecasters come from many backgrounds, and the writer of that bulletin is a true snow scientist.  But she wasn't just getting carried away with the details of a Low rating.  In typical Sierra fashion, a big snowstorm was on the way, coming on top of all those instabilities.

Here's the result in the form of the March 17 bulletin:

The avalanche danger is HIGH. Over two feet of new snow has fallen overnight. Natural avalanches with crowns 2 to 3 feet thick are running on June Mountain. Natural and human triggered avalanches are very likely today. Large avalanches will occur in many areas. Very large avalanches can occur in steep wind loaded terrain. 
Heavy snow continues to fall on a weak snowpack adding to the unstable conditions.