• For more information on how to avoid pop-up ads and still support SkiTalk click HERE.

tball

Unzipped
Skier
SkiTalk Supporter
Joined
Nov 12, 2015
Posts
4,362
Location
Denver, CO
acc_490_4356.jpg


That's the 2013 inbounds persistent slab avalanche at Arapahoe Basin. It caught 15 people, partially buried six, and fully buried one as they took guests back there for the first time of the year.

The longest ride was nearly 700 vertical feet. It's remarkable nobody died. It's very much worth reading the CAIC report:

https://avalanche.state.co.us/caic/acc/acc_report.php?acc_id=490&accfm=inv

A-basin bombed the crap out of that, and it still slid big. They are now using a compaction roller to break up the persistent slab.

1-2-18 2.jpg

http://arapahoebasin.blogspot.com/2018/01/compaction-roller-in-montezuma-bowl.html
http://arapahoebasin.blogspot.com/2016/09/new-device-compaction-roller.html

At each area I ski, I'd like to know which runs have been compaction rolled, which have been boot packed, and on which only explosives have been used. Or, no explosives at all as in Prima Cornice at Vail. And, why for extra credit.

That information would very much inform my choice to ski a run, especially for the first few days a run is open for the season when the risk of a persistent slab avalanche is greatest.
 
Last edited:

karlo

Out on the slopes
Inactive
Joined
May 11, 2017
Posts
2,708
Location
NJ
The fact that they opened it, mean that patrol considers this to be an acceptable level of risk, right?

I’d be interested in knowing what the forecasters would rate the risk, if they had the in-resort snow pack conditions. It’d be like a calibration of patrol assessments. Even get patrol staff from different resorts to assess each other’s resorts as part of a larger gauge study.

Usually 25deg and below.
39 deg is the center of the danger curve except for "low probability" conditions.
img_5839-jpg.64974

Is that data showing probability of certain size slides or human injury? If the latter, then the low probability at the higher steepness might have more to do with how few skiers ski it.

I’m guessing that the local patrol has been pounding away at persistent weak layers all season long such that they don’t exist inbounds. That, plus they’re keeping terrain closed after a storm, until migration work is done, I feel pretty safe. I would bother with avy gear on inbounds terrain. Buddy, yes. Recco, yes.
 

jmeb

Enjoys skiing.
Skier
Joined
Nov 13, 2015
Posts
4,490
Location
Colorado
I would bother with avy gear on inbounds terrain. Buddy, yes. Recco, yes.

Guessing you mean "wouldn't bother".

IMHO -- if you have a beacon, no reason not to wear it. Every patroller at a hill with potential for avalanches carries a beacon and trains on it consistently. RECCO devices are much further away, slower and less precise to use. If you're buried -- a beacon is by far your best hope for a quick recovery.
 

dusty

Getting on the lift
Skier
Joined
Mar 14, 2016
Posts
182
Totally agree with above. If you can beep, beep on high danger days inbounds. I was caught in an inbounds avy two years ago at Fernie. Having it helps assist recover.
 
Thread Starter
TS
Slim

Slim

Making fresh tracks
Skier
SkiTalk Supporter
Joined
Oct 2, 2017
Posts
2,973
Location
Duluth, MN
To follow up:
As suggeste by several people, since I posed this question, for the rest of the season, whenever I ran into a patroller, I asked them about the avalanche risk. Partly to get more information to inform my decisions on that day, and partly because it’s fun and helps me learn more about snow safety and avalanches in general.
 

TexasStout

Epic Pass + Loveland 4-pack for 2021-2022
Skier
Joined
Nov 24, 2015
Posts
698
Location
Texas and Colorado
To follow up:
As suggeste by several people, since I posed this question, for the rest of the season, whenever I ran into a patroller, I asked them about the avalanche risk. Partly to get more information to inform my decisions on that day, and partly because it’s fun and helps me learn more about snow safety and avalanches in general.
Thanks for the idea. Since I'm now skiing more steep terrain than I did even two years ago, I would like to hear from patrollers before I venture onto the higher risk slopes. Gonna start asking when I see them.
 

Decreed_It

I'd rather be skiing
Skier
Joined
Jan 9, 2019
Posts
905
Location
Northern Beaches, Sydney, Australia
Bought a BCA kit last year, in large part due to this thread and some trips we took - I'll be wearing the beacon on trips this year, mentally I treat it as wearing a seatbelt in the car. Plus with some of the very early season snow, mid to late season risk could be higher, based on my very basic/limited knowledge and reading. Like @jmeb said if you have one no reason not to wear it.
 

mdf

entering the Big Couloir
Skier
Team Gathermeister
SkiTalk Supporter
Joined
Nov 12, 2015
Posts
7,220
Location
Boston Suburbs
Bought a BCA kit last year, in large part due to this thread and some trips we took - I'll be wearing the beacon on trips this year, mentally I treat it as wearing a seatbelt in the car. Plus with some of the very early season snow, mid to late season risk could be higher, based on my very basic/limited knowledge and reading. Like @jmeb said if you have one no reason not to wear it.

Good idea. I have a beacon I always wear in the west, even when it feels silly. That way you don't have to decide.
I bought my beacon the year there was a slide that caught a guest in Toilet Bowl at Jackson Hole. That year they posted a note on the snow report page, "ski patrol suggests that anyone skiing double black terrain should wear a beacon."

Edit to add-- my beacon is getting pretty old, even though it still works fine, I think I will replace it with the newest BCA unit. Plus, having two will make it easy to practice.
 
Last edited:

jmeb

Enjoys skiing.
Skier
Joined
Nov 13, 2015
Posts
4,490
Location
Colorado
Plus with some of the very early season snow, mid to late season risk could be higher, based on my very basic/limited knowledge and reading.

The concern is very early snowfall followed by long stretches of dry, cold weather. i.e. What we have had at Colorado until today/tomorrow. As of yesterday, our snow safety director mentioned faceting to the ground on all aspects across the ski area. That is not what you want to build a snowpack on top of.
 
Thread Starter
TS
Slim

Slim

Making fresh tracks
Skier
SkiTalk Supporter
Joined
Oct 2, 2017
Posts
2,973
Location
Duluth, MN
Last edited:

pais alto

me encanta el país alto
Skier
SkiTalk Supporter
Joined
Nov 11, 2015
Posts
1,937
Location
The concern is very early snowfall followed by long stretches of dry, cold weather. i.e. What we have had at Colorado until today/tomorrow. As of yesterday, our snow safety director mentioned faceting to the ground on all aspects across the ski area. That is not what you want to build a snowpack on top of.
This. Living in the southern Rockies I pretty much hate early snows for this reason. Early snow followed by a long cold dry spell was a major factor in last year’s Taos accident and general sketchy snowpack around here.

If you have your beacon and associated gear and have taken Basic avy training, then paying attention to the weather patterns and events where you ski and linking it to snow stability is an excellent next step in your avy awareness. Facets, surface and depth hoar, persistent weak layers, temperature and precipitation cycles...fascinating stuff if you’re at all interested/concerned about avys.
 

karlo

Out on the slopes
Inactive
Joined
May 11, 2017
Posts
2,708
Location
NJ
whenever I ran into a patroller, I asked them about the avalanche risk.

So? Did any give you an iron clad assurance that it was safe?

Not quite sure what you mean, here’s my guess, correct me if I’m wrong: ogwink


...wearing a beacon in transmit mode


At the scene of an avalanche rescue


... to switch your beacon to search mode


..turn your cellular phone off.

Oooh, that’s what he meant!
 

PNWRod

Getting off the lift
Skier
Joined
Nov 9, 2017
Posts
301
Location
Crystal Mtn
Although I've carried my beacon, shovel and probe for years I'm starting to look for a side /slack country airbag. Since it's lift served I don't want it too bulky but yet able to hold all the avy gear + hydration and a few snacks. So far everything that I've found is quite a bit larger than I was expecting. The minimum size I've found so far is the Mammut Ultralight. Still researching.
 

pais alto

me encanta el país alto
Skier
SkiTalk Supporter
Joined
Nov 11, 2015
Posts
1,937
Location
Although I've carried my beacon, shovel and probe for years I'm starting to look for a side /slack country airbag. Since it's lift served I don't want it too bulky but yet able to hold all the avy gear + hydration and a few snacks. So far everything that I've found is quite a bit larger than I was expecting. The minimum size I've found so far is the Mammut Ultralight. Still researching.
http://www.blackdiamondequipment.com/en/pieps-jetforce-bt-10-PP681321_cfg.html
 

Shawn C.

Out on the slopes
Skier
Joined
Sep 3, 2017
Posts
403
Location
Ogden, UT
...whenever I ran into a patroller, I asked them about the avalanche risk. Partly to get more information to inform my decisions on that day, and partly because it’s fun and helps me learn more about snow safety and avalanches in general.

I need to do this. The snowcat skiing at Powder Mountain has, at times, freaked me out. A lot of the terrain doesn't seem to get much skier compaction.
 

karlo

Out on the slopes
Inactive
Joined
May 11, 2017
Posts
2,708
Location
NJ
Very sad that there have been fatalities at Silver,


The author of the linked article writes,

“Our understanding was avalanche mitigation with explosive charges had been completed off the top of Wardner Peak before skiers and boarders entered the then uncut traverse.”

Is that it? Do all resorts set off charges and that’s the end of it? Or, at some, and evidently not at Silver, do patrollers check stability afterwards, before opening terrain?
 

jmeb

Enjoys skiing.
Skier
Joined
Nov 13, 2015
Posts
4,490
Location
Colorado
Is that it? Do all resorts set off charges and that’s the end of it? Or, at some, and evidently not at Silver, do patrollers check stability afterwards, before opening terrain?

It varies massively by the ski area in question, and more importantly the avalanche path in question, the snow pack, and the avalanche problem. There isn't a sure fire way to "check stability" really. They could do an ECT i suppose, but that is a super isolated result and not generalizable to even terrain on one general face. Throwing a bunch of charges is a pretty good way to "test stability" before opening terrain. Other options for managing are ski cutting, directed skiing, cornice cutting, and more.

Then you're faced with the problem that skiers don't want patrol going out and diagonally ski cutting every slope over 30-degrees after a storm. Patrons don't like it when patrol ruins the freshies, and it isn't exactly fun to do anyhow.

Patrol isn't opening anything they *think* has the slightest likelihood of sliding. Obviously hindsight is 20/20.
 

tball

Unzipped
Skier
SkiTalk Supporter
Joined
Nov 12, 2015
Posts
4,362
Location
Denver, CO
With the recent fatalities at Silver Mtn, It seems like there's an increasingly clear pattern of inbounds avalanches early season on terrain that's recently opened. It's always been fairly apparent but probably worth emphasizing following this tragedy.

I'd love to see a study of how many inbounds fatalities have been in late December or January on recently opened terrain. I bet it would be eye-opening.

I'm using this as a motivator to wear my beacon when I otherwise wouldn't the next few weeks, even if there isn't much new snow. It seems far more important to do so this time of year than on similar days in March and April.

Am I off base with this thinking?
 

Sponsor

Top