Avi at silver

Discussion in 'General' started by POW HEAD, Jan 7, 2020.

  1. teledance

    teledance

    Location:
    N. ID
    You'll have to let me know when I'm not using situational awareness, I've been skiing for several decades and BC for almost 40, and have no problem not hitting something because of SA and what I see and if you worked there you know all the trigger points I mentioned back to SA.
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  2. Teledance-

    I was not stating anything of the sort and I apologize if it was construed in that way. I only say that because we have many new-to-BC folk on this website without that level of experience. Plus I always default to be leery whenever I hear "I have never seen that slide in X years!" no matter who says it or with any experience. I certainly meant no disrespect.

    BG
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  3. teledance

    teledance

    Location:
    N. ID
    All good little touchy last week, I did say that yesterday though in reference to a SC run and then qualified it with the fact it just barely got enough snow to ski it, plenty of anchors still showing on BP, smooth though.
  4. Everyone was a little touchy after the big slide...Brent is correct, situational awareness is important. Not a difficult concept...Every slope is different pretty much every storm or weather change...in bounds or not. When approaching said slope, you assess it 'that' day, you don't use old data. You also assess it relative to who you are skiing with as well. That is simple BC principals 101. Any slope above 30 degrees is a candidate to slide, whether it ever has or not.

    BTW the BC has been, well, awesome the past few days! As good as it gets, at least in the Selkirks...Enjoy, be safe. Very little room for judgement errors in conditions like this!
    ~Tiny
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  5. I like using old data as the basis for my new data. Season long observations are gold when dealing with chronic instability, or lack of. A pit is full of old data. In the BC, following the 24-Hour Rule means sometimes first track are not had on steep terrain... while others might get the goods or slabs, you missed it doing low angle safe powder. But it's worth the margin of safety IMO when dealing with storm snow.
    teledance likes this.
  6. teledance

    teledance

    Location:
    N. ID
    Keeping track of the layers over the season is part of job and like VT I prefer to let fresh snow settle unless I've been skiing an area through all the storm cycles. Even then I still might give it a day, conditions dependent.
  7. Now come on guys, by "old" data, I mean a statement like, "I've never seen that slide before"...Of course you assess what is in the snow, not just that day's snow...its the combination of weather events...Geez, a bit literal are we? As for the 24 hour rule, I agree, but don't necessarily follow. If the resorts are crowded I'm gone, no matter...Some days you just simply know not to press...I do not recommend folks play this way unless they have many years/days/hours of experience (not class time... experience). There is no better way to learn the snow than to go out on those days when danger is high...learn to be offensive...learn on safe slopes how the snow reacts...Probably ought to have a buddy with you as well that is just as knowledgeable and keen for an active day. IMHO
  8. jah.. I get being offensive, but prefer playing defense :). ..I might be assuming, but me thinks the vast majority of avalanche fatalities in the US/Canada occur during or shortly after a storm cycle.
    teledance likes this.
  9. You would be correct on post-storm danger, and I get that. Hopefully, since I've been playing this game since the late 70's, I've got a handle on route finding and safe slopes...assuming I didn't just jinx myself. By offensive I don't mean kicking off a cornice to make entry into a couloir safer, not in these conditions anyways. It means going out with a focus of skiing low angle slopes, popping the occasional convexity before dropping below it and especially safe route finding. The tolerances just get tighter in conditions such as we've had. No mistakes. That said, skiing is awesome because there are any number of ways to enjoy it no matter your level or conditioning.
    ~Tiny
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  10. JerryJ

    JerryJ

    Location:
    Bozeman
    Has anyone seen any snowpit data from the accident scene?

    May as well join in this conversation: I patrolled Silver (then Silverhorn) in the 70s and skied it as a kid before the area opened. My parents helped develop it. Have been in touch with some other old timers and we can come up with only one or two instances of slides in this spot - exclusively due to cornice drops after a shot and it never went all the way to the bottom. I have kicked small slides off the top with ski cuts but again small. This is a rare event and so the pit data is important.

    Jerry Johnson, MSU Snow and Avalanche Lab
  11. Bill A.

    Bill A.

    Location:
    Spokane, WA
    Jerry,

    Melissa (@Mtnbikemelissa), our resident Idaho Panhandle Avalanche forecaster for the Silver Valley and @Katrinaandrocket posted about instability on those slopes in late December (12/22/2019), before we started getting our New Years snowfall —
    Instagram Link . Unfortunately no pit data.

    Here's a public observation, several days later (12/28/2019) in the same area — https://www.idahopanhandleavalanche...extended-column-testing-rutschblock-site-1222

    After the Silver Mountain slide, Katrina did a pit further east along the ridgeline — https://www.idahopanhandleavalanche.../jan/12/east-ridge-silver-mountain-snow-pilot

    Anecdotally, the 6-8" that fell Sunday night-Monday was very light with a fair amount of wind transport. Even Monday mid-afternoon, my wife and I were doing laps of Corkscrew (looker's left off Chair 4; Melissa & Katrina's pit [above] were looker's right) and had fun being chased by the sluff trains on a well-tracked slope. The 12"+ that fell Monday night-Tuesday was quite a bit heavier in a warming trend. The nearest SNOTEL site (Sunset) hints at that. For us, everything seemed to be upside down on top of the instability that Melissa & Katrina found, so we opted for the safer runs near Chairs 2 & 3 that day.

    Bill
    Last edited: Jan 18, 2020 at 12:47 PM
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  12. rdb

    rdb

    Location:
    Idaho
    The bottom photo is the first I have actually seen of "a" or "the" avi off what appears to be the north shoulder, east side of Warner. Is that a photo of the slope that actually slide....or just one of the slopes that slide? The trail map drawing and red shaded area shows avis running off the top of Warner (16:1) and off that north shoulder. The one actual terrain photo seems to match the terrain for the north shoulder.. Does anyone posting here know what part of the mountain actually did slide? Photos? Just for historical context, like Jerry wrote above I have never seen a slide of any size in that area while the ski area was *open* to the public, going back to the Jackass days. Never seen a slide from the top of Warner either. But the bare ground of Warner and the historical avalanche paths (from the top of Warner literally into the town of Warner 3500'+ below) tell us it has happened in the past. There were similar slides (nothing this big thought) I can remember on the exact same slope during major storm events that generally occurred at night (I saw them while grooming the run below the debris field). Just nothing as big as what the two were in this incident. But worth noting the slide area shown in the photo and the area around/above/beside it got a lot more skier traffic when it was just the one original lift available to skiers on the mountain. As well as the bottom of that particular slope being undercut consistently by the ski area snow machines while grooming.

    In the '80s a woman was injured in a small avi on top, west side of Sheer Bliss. Never known of control efforts by the ski area besides just skier traffic, any where past the east ridge line and summit of Warner. When the area changed boundary lines to incorporate the west side of Warner did that change? During the '70s there were 12 distinct bomb sites (pillows or cornices) on the ridge from the start of the Warner traverse going up the ridge ending at the top of Warner (16:1's) biggest open slope.

    I read this above, "They blasted the Wardner in the morning and shortly after it opened up it happened." And from Bill's FB post, "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.". Lots of terrain covered in those two statements. Does anyone know if the Patrol ski cut or bombed the ridge going up Warner the morning of the avalanche? Was the top of 16:1 (Warner Summit) bombed or ski cut that morning, prior to opening? Anyone from the patrol hike over the top of Wardner and or ski into the west side bowl of Warner prior to opening?

    In the Silverhorn/Jackass days it was common for Warner to stay closed 12 to 36 hrs after a major storm event. This when there was only one chair and the public pressure to open Wardner was very high. Unsuspected then, the lack of man power and resulting time lags to open Wardner might well have been the best control technique we had at the time.

    As an after thought. From the opening of the area in the late '60s and the one chair, it was typically un-skied Kellogg Peak (now Skyway Ridge) that was seen a bigger threat than Wardner as a avi area. Simply because Kellogg wasn't controlled often and saw little to no skier traffic while threatening a large portion of the terrain skiers did use. String lines of 100 sticks of dynamite and or rope cutting the cornice was common there. Hard to visualize any of that now with the change in skier traffic patterns.

    From the debris field being reported as 10' deep and my own experience in the ski area, and on Warner specifically, I have no doubt the storm that night was a unique wind event with the resulting snow load. Tragic for all involved. So sorry for that.

    Just trying to learn something from it. Thanks. Be careful out there!

    [​IMG]

    [​IMG]
    Last edited: Jan 20, 2020 at 11:12 AM
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  13. teledance

    teledance

    Location:
    N. ID
    I have heard about slides on the other side of Wardner but haven't heard if it was South or West aspects.
  14. good stuff rdb. Local knowledge most helpful! Unusual snow and weather events can and do produce unusual avalanche cycles. Not sure if the weather preceding the event was "unusual" in that I have little knowledge of historic weather patterns around Silver.

    "Best deep powder skiing in years" would be an example of unusual as would be "record amounts" or "near record winds" as a storm ends. There is so much energy in fresh deep, snow,.... stable one moment, not so much the next, then settled, then not..... It can and does change frequently. So again, it's critical to emphasize the importance of the 24-rule as the basis for all decision making after a storm. So if a storm ends at 8am as your throwing your skis and skins in the car, you should tour low angles and wait til the following day to ski avalanche terrain. If a storm ends at 5pm, you may should wait out the next day. Overnight is not 24 hours. Storm ends at noon, then after noon the next day.

    Think I'll be skiing Silver next weekend for the first time and look forward seeing this zone.
    Bill A. likes this.
  15. rdb

    rdb

    Location:
    Idaho
    Jerry and I have been discussing the effect of skier traffic, which has virtually no effect on deep unstable layers. In turn those snow profiles are only known from snow pit data. Even with snow pit data there is little ability to change those layer profiles beyond carpet bombing the slope through out the season or may be better yet run a grooming machine down the slope after every major storm. And the flip side to snow pit data for me, is a major storm event and the resulting wild blown snow loads and pillows.

    Which in turn gets back to the 24hr rule.

    This was the best article (listed prior) I have seen. It specifically notes the route Morning Star as one location of the slide. Which is the run pictured with the avalanched slope.

    https://www.shoshonenewspress.com/local_news/20200107/two_killed_in_silver_mountain_avalanche

    [​IMG]

    [​IMG]


    From the top of Kellogg looking West and the avi zone pictured from the photo above. Anyone have a photo of the start zone on 16:1 ? This is the same ridge line on Kellogg that at one time was THE major avalanche threat of many on Silver.

    [​IMG]

    Green outline would seem to be the debris field in the photos (16:1 slide?) and red the slide off Morning Star
    [​IMG]
    Last edited: Jan 20, 2020 at 4:01 PM
  16. idsnowghost

    idsnowghost Staff Member

    Location:
    Spokane, WA
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  17. idsnowghost

    idsnowghost Staff Member

    Location:
    Spokane, WA
    For some more perspective, Silver Mt by air (not my photo, not recent):

    Wardner top right:
    silvermt_byair.jpg
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  18. rdb

    rdb

    Location:
    Idaho
    Thanks. Below are the photos and captions from the ACC report. The approximate avalanche boundary is outlined in red. Confusing as the two line drawings from the report don't match up. Although the lower line drawing pictured seems to be on a late Spring slope used for clarity, the search area lines does match up to the search area that can be seen in the helicopter footage. And no mention of a slide on Morning Star pictured previous in the thread.

    ”They had done their control work just like they always do,” Jeff Thompson, the director of the avalanche center, told The Spokesman-Review newspaper. “In fact, I think they did more than they normally do to open that slope.”
    [​IMG]

    Green triangle is the summit of Warder and directly below that is run 16:1.
    [​IMG]
  19. idsnowghost

    idsnowghost Staff Member

    Location:
    Spokane, WA
    Yeah, I think the drawing on the trail map is off a bit? Hopefully the full report will clear up a lot of these ambiguities.

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