February 28, 2009, Crooked Couloir conditions
2/28/09
4377
12
Posting this with the permission of my friend, the narrator, to share the conditions.
***********
Before Leaving the House:
Lee, Todd and I all decided to generally head up to the Snoqualmie area to do a tour on Saturday. We briefly talked about the options of Crystal BC vs Snoqualmie specifically with regard to the ice layers that I had read about on a couple TAY trip reports from Wednesday of the previous week. Lee was generally concerned about the quantity of new snow. Our conclusion was that we would loosely like to do the Crooked Couloir, but we would read the forecast & Avy Report on the way up and make a group decision during the drive. We brought topo maps for a variety of conservative tour alternatives.
On the drive up, the forecast was for temps to hold until late afternoon. Avy forecast for "east slopes of central cascades moderate above 4-500' and low below". Storm totals from the past 3 day was 15" at the passes with up to 25-35" near the crest". We concluded that we would try to do the Crooked with an easy bail-out down the south facing approach slope and that we would dig a few pits on the way up to help our decision.
Approach:
Wind was from the SE, temps were about 30 degrees and wind was consistently strong and gusting up to 35mph once we were high on Snoqualmie Ridge. At some points it was very hard to stand up. Left the car around 8:45AM.
We took a pretty mellow pace and dug a few "hasty pits" down to about 24 - 30" deep which was just below the major ice layer. We found that the south facing aspect profile had about 15" of new, consistently bonded (fist hole)powder to a layer of very well defined "mega crust" that was about 6 - 8" thick. The new snow was well bonded to the mega crust. This layer appeared well bonded to the consolidated snow below. We found no smooth shear layers. On the windy ridge, we were consistently pushing off small sluffs that originated from a surface layer that was maybe 2- 4" thick. We concluded this was the result of a wind and solar crust. The sluffs did not propagate or result in anything larger than loose chunks as a skier skinned along. Much of the ridge was wind scoured with patches of bullet-proof ice.
Topping Out:
We summited around 12:45 with consistent winds, but they appeared to have subsided a bit from earlier. We tried to evaluate the normal entry into the Crooked, but there appeared to be cornices that made it difficult to see in and eliminated the standard entry as a feasible option. We boot packed down along the ridge about 100' to the NE were we found a gently entry. The first 50' I estimated at 50 + degrees transitioning to around 35-40 degrees. We dug a pit on the NE aspect using our poles down about 36" and found the snow consistent with no discernable layers. We were concerned about the quantity of lee aspect loading and talked about this pitch as well as the narrow couloir below. Our main concern was this new snow sliding on the layer below. We felt that once we were past this heavily loaded upper 100', we were much more confident. We felt we could boot down about 100' and to our left onto a less steep section with mostly rocks above to avoid the section that concerned us. Lee booted down and then skied the whole slope without incident. Todd boarded halfway down and a slide cut loose that propagated to be about 100' wide. The Crown varied from 0" to 18" depending on the loading and was clearly the new snow on a smooth firm layer. I skied down the slide path and we continued down the Crooked.
Crooked Couloir Proper:
Once were about 200' above the steep center section of the couloir, we dug two more hasty pits using our poles down about 24". In each pit we had to pull like hell to get the column to release, but both pits yielded Q2 shears and the slabs/chunks that released were fairly well consolidated to the point we could lift them up intact. We decided not to ski the couloir proper and instead make a dogleg into the trees to skier's right, skipping all but the last 100' of the couloir. Lee worked his way slowly out into the couloir while jumping and making a couple test turns. While he was doing this, two skiers emerged below from having just skied the Slot Couloir. Lee skied our couloir and then stopped about 400' below and waited to skier's left. I went 2nd and waited next to Lee. Todd went third and just as he entered the same initial ski track, the couloir cut loose at our ski track and the whole lower couloir slid carrying Todd down. Todd & the slide went right by Lee and I. We yelled at him that were watching him and to try to stand up and ride out to the side. The slab chunks were about 18" thick and quickly dissipated into loose snow and Todd was carried about a total of 500' down to about 200' below Lee and I. He was not buried, not hurt and didn't loose any gear.
Descent:
We skied down the rest of the slope in the small trees and transitioned at the valley. The ski back down the south aspect slope was very consolidated with a 3" sun crust. The trees still held nice snow.
My Personal Take-Aways (these are not necessarily shared by Todd or Lee):
Our go/no-go decision was wrong. We should have bugged-out and conservatively skied the south facing approach slope. I knew before we left the house that we had a new storm snow on a very old, well-defined ice layer from the past month's conditions. At our go/no-go decision I knew this would not be a bomber snow pack, but, it appeared reliable and consistently bonded after numerous tests. I was the least confident of the group. On a scale of 1-10, 10 being the perfect velcro bonding on of new snow to existing layers, I think I was at about a 6-7.
All our decisions after the go/no-go were well thought-out. We followed rigid BC protocol: one at time, good spacing, always having at least two sets of eyes on the skier. Constantly re-evaluated the slope and conditions. Talked constantly.
My gut is that my confidence in this particular group of ski partners influenced my willingness to agree with the go/no-go decision. I am 100% confident in Lee for beacon and first aid and I'm 100% confident in Todd's beacon and rescue skills. Had I been with partners that I had less confidence in, I would likely have not skied the slope. That said, I realize that commenting on beacon skills is akin to commenting on the strength of your car's seatbelts.
<corrected year - mod>
***********
Before Leaving the House:
Lee, Todd and I all decided to generally head up to the Snoqualmie area to do a tour on Saturday. We briefly talked about the options of Crystal BC vs Snoqualmie specifically with regard to the ice layers that I had read about on a couple TAY trip reports from Wednesday of the previous week. Lee was generally concerned about the quantity of new snow. Our conclusion was that we would loosely like to do the Crooked Couloir, but we would read the forecast & Avy Report on the way up and make a group decision during the drive. We brought topo maps for a variety of conservative tour alternatives.
On the drive up, the forecast was for temps to hold until late afternoon. Avy forecast for "east slopes of central cascades moderate above 4-500' and low below". Storm totals from the past 3 day was 15" at the passes with up to 25-35" near the crest". We concluded that we would try to do the Crooked with an easy bail-out down the south facing approach slope and that we would dig a few pits on the way up to help our decision.
Approach:
Wind was from the SE, temps were about 30 degrees and wind was consistently strong and gusting up to 35mph once we were high on Snoqualmie Ridge. At some points it was very hard to stand up. Left the car around 8:45AM.
We took a pretty mellow pace and dug a few "hasty pits" down to about 24 - 30" deep which was just below the major ice layer. We found that the south facing aspect profile had about 15" of new, consistently bonded (fist hole)powder to a layer of very well defined "mega crust" that was about 6 - 8" thick. The new snow was well bonded to the mega crust. This layer appeared well bonded to the consolidated snow below. We found no smooth shear layers. On the windy ridge, we were consistently pushing off small sluffs that originated from a surface layer that was maybe 2- 4" thick. We concluded this was the result of a wind and solar crust. The sluffs did not propagate or result in anything larger than loose chunks as a skier skinned along. Much of the ridge was wind scoured with patches of bullet-proof ice.
Topping Out:
We summited around 12:45 with consistent winds, but they appeared to have subsided a bit from earlier. We tried to evaluate the normal entry into the Crooked, but there appeared to be cornices that made it difficult to see in and eliminated the standard entry as a feasible option. We boot packed down along the ridge about 100' to the NE were we found a gently entry. The first 50' I estimated at 50 + degrees transitioning to around 35-40 degrees. We dug a pit on the NE aspect using our poles down about 36" and found the snow consistent with no discernable layers. We were concerned about the quantity of lee aspect loading and talked about this pitch as well as the narrow couloir below. Our main concern was this new snow sliding on the layer below. We felt that once we were past this heavily loaded upper 100', we were much more confident. We felt we could boot down about 100' and to our left onto a less steep section with mostly rocks above to avoid the section that concerned us. Lee booted down and then skied the whole slope without incident. Todd boarded halfway down and a slide cut loose that propagated to be about 100' wide. The Crown varied from 0" to 18" depending on the loading and was clearly the new snow on a smooth firm layer. I skied down the slide path and we continued down the Crooked.
Crooked Couloir Proper:
Once were about 200' above the steep center section of the couloir, we dug two more hasty pits using our poles down about 24". In each pit we had to pull like hell to get the column to release, but both pits yielded Q2 shears and the slabs/chunks that released were fairly well consolidated to the point we could lift them up intact. We decided not to ski the couloir proper and instead make a dogleg into the trees to skier's right, skipping all but the last 100' of the couloir. Lee worked his way slowly out into the couloir while jumping and making a couple test turns. While he was doing this, two skiers emerged below from having just skied the Slot Couloir. Lee skied our couloir and then stopped about 400' below and waited to skier's left. I went 2nd and waited next to Lee. Todd went third and just as he entered the same initial ski track, the couloir cut loose at our ski track and the whole lower couloir slid carrying Todd down. Todd & the slide went right by Lee and I. We yelled at him that were watching him and to try to stand up and ride out to the side. The slab chunks were about 18" thick and quickly dissipated into loose snow and Todd was carried about a total of 500' down to about 200' below Lee and I. He was not buried, not hurt and didn't loose any gear.
Descent:
We skied down the rest of the slope in the small trees and transitioned at the valley. The ski back down the south aspect slope was very consolidated with a 3" sun crust. The trees still held nice snow.
My Personal Take-Aways (these are not necessarily shared by Todd or Lee):
Our go/no-go decision was wrong. We should have bugged-out and conservatively skied the south facing approach slope. I knew before we left the house that we had a new storm snow on a very old, well-defined ice layer from the past month's conditions. At our go/no-go decision I knew this would not be a bomber snow pack, but, it appeared reliable and consistently bonded after numerous tests. I was the least confident of the group. On a scale of 1-10, 10 being the perfect velcro bonding on of new snow to existing layers, I think I was at about a 6-7.
All our decisions after the go/no-go were well thought-out. We followed rigid BC protocol: one at time, good spacing, always having at least two sets of eyes on the skier. Constantly re-evaluated the slope and conditions. Talked constantly.
My gut is that my confidence in this particular group of ski partners influenced my willingness to agree with the go/no-go decision. I am 100% confident in Lee for beacon and first aid and I'm 100% confident in Todd's beacon and rescue skills. Had I been with partners that I had less confidence in, I would likely have not skied the slope. That said, I realize that commenting on beacon skills is akin to commenting on the strength of your car's seatbelts.
<corrected year - mod>
thanks for shareing - sounds scary.
<ditto>
<ditto>
Good info, Marcus.
Thanks.
Thanks.
Whoa Marcus, thanks for sharing the narrative.
I honestly am a bit shook up at the moment because after a quiet winter thus far, 4 stories of near miss incidents have surfaced in one week.
One is the burial and rescue of the fiancé of the daughter of a friend that happened in the Vahallas. The other three are Central Cascades localities: this story, the one Zap has provided the weblink for in Random Tracks, and the one on the NWAC report of a snowmobile at Gallagher Head Lake area. All this activity all of the sudden when we've kinda been lulled into seemingly stable conditions.
I'm just glad that no one was seriously injured. Hits a bit too close to home literally and figuratively.
John
I honestly am a bit shook up at the moment because after a quiet winter thus far, 4 stories of near miss incidents have surfaced in one week.
One is the burial and rescue of the fiancé of the daughter of a friend that happened in the Vahallas. The other three are Central Cascades localities: this story, the one Zap has provided the weblink for in Random Tracks, and the one on the NWAC report of a snowmobile at Gallagher Head Lake area. All this activity all of the sudden when we've kinda been lulled into seemingly stable conditions.
I'm just glad that no one was seriously injured. Hits a bit too close to home literally and figuratively.
John
Indeed it does, John. Spooky stuff. From the pit results in my avy class Saturday and Sunday, it's a very complex snowpack right now. Ought to make for an interesting couple of months.
Marcus - thank your friend for sharing this.
JoeCat's report of kicking off a slide at Heather Ridge on Thursday (yet another recent report is in part what led my party (one of whom was fully buried about 20 years ago and who now demostrates what I'd call healthy caution - something I'm willing to listen to but don't always exhibit to the same degree when left to my own) to head to the relatively moderate treed slopes of Yodelin on Saturday. We noticed a bit of a warming around noon (and heard another group mention the heavier snow). I see on telemetry that Alpental saw the same warming trend mid-day. I wonder if this was a factor in the slide(s) in this report.
JoeCat's report of kicking off a slide at Heather Ridge on Thursday (yet another recent report is in part what led my party (one of whom was fully buried about 20 years ago and who now demostrates what I'd call healthy caution - something I'm willing to listen to but don't always exhibit to the same degree when left to my own) to head to the relatively moderate treed slopes of Yodelin on Saturday. We noticed a bit of a warming around noon (and heard another group mention the heavier snow). I see on telemetry that Alpental saw the same warming trend mid-day. I wonder if this was a factor in the slide(s) in this report.
Scary indeed. Marcus, thanks for sharing this excellent account. I'm very glad to hear everyone was OK.
I have a few observations and one question. First the question: the Crooked exit where the slide occurred looked horrible a few weeks ago with a big ice bulge. I assume it's covered now since the report didn't mention anything about it, but probably only shallowly. Did this thin coverage/underlying ice have anything to do with the slide
We took a tour on Saturday the same day this slide occurred on Kendall and skied all aspects. The wind was blasting all day from the SE as also reported in the post and had damaged most NE facing terrain down to relatively low elevations (4500 ft) with a wind crust or fully wind pressed snow. Because of the wind effect, we found NE slopes mostly stable. However, NW facing terrain out of the wind had excellent low density powder but it was very sensitive. We got several very easy and clean shears about 12" or more down (within the new snow, not on the January crust) on small roll overs and managed terrain very carefully in the steep glades we were skiing.
The Crooked is an interesting tour because it covers almost all aspects. The approach is on south facing slopes that because of the sun on Thursday and Friday were heavily crusted. So the pits on the ascent, while interesting had little to do with the snow in the Crooked. Then, the descent off the top of Mt Snoqualmie (I assume they approached via Alpental and the Phantom) is NE facing, but after the initial drop in the north bowl the couloir bends to exit on a NW facing slope. There is even a little pinnacle and saddle just N-NE of the couloir exit that will funnel easterly winds and help load the exit. I wonder if this contributed to the slide.
I have a few observations and one question. First the question: the Crooked exit where the slide occurred looked horrible a few weeks ago with a big ice bulge. I assume it's covered now since the report didn't mention anything about it, but probably only shallowly. Did this thin coverage/underlying ice have anything to do with the slide
We took a tour on Saturday the same day this slide occurred on Kendall and skied all aspects. The wind was blasting all day from the SE as also reported in the post and had damaged most NE facing terrain down to relatively low elevations (4500 ft) with a wind crust or fully wind pressed snow. Because of the wind effect, we found NE slopes mostly stable. However, NW facing terrain out of the wind had excellent low density powder but it was very sensitive. We got several very easy and clean shears about 12" or more down (within the new snow, not on the January crust) on small roll overs and managed terrain very carefully in the steep glades we were skiing.
The Crooked is an interesting tour because it covers almost all aspects. The approach is on south facing slopes that because of the sun on Thursday and Friday were heavily crusted. So the pits on the ascent, while interesting had little to do with the snow in the Crooked. Then, the descent off the top of Mt Snoqualmie (I assume they approached via Alpental and the Phantom) is NE facing, but after the initial drop in the north bowl the couloir bends to exit on a NW facing slope. There is even a little pinnacle and saddle just N-NE of the couloir exit that will funnel easterly winds and help load the exit. I wonder if this contributed to the slide.
We've had extensive email discussion about the particulars -- the general consensus seems to be that the lower slide was likely effected by the ice layer. Pictures from the slide made it look like it was probably the bed surface, or at least very close to the top, perhaps facilitating depth hoar formation, or just lubricating the snow above. They said they couldn't ski about a 1/4 of the couloir due to ice/inadequate snow cover.
Another theory of mine (I've not done the Crooked, so I'm not totally familiar with the terrain) was that, since Snoqualmie sticks up in the the crest winds so prominently, that the wind loading may have effected slopes considerably farther downhill than you might find at a typical ridge, since the air would slow considerably on the lee side of the whole mountain, and drop more snow into the couloirs as a result.
Anyway, thanks for the thoughts. My friend is following the thread, I think, and we've had a lot of good discussion around this incident.
Another theory of mine (I've not done the Crooked, so I'm not totally familiar with the terrain) was that, since Snoqualmie sticks up in the the crest winds so prominently, that the wind loading may have effected slopes considerably farther downhill than you might find at a typical ridge, since the air would slow considerably on the lee side of the whole mountain, and drop more snow into the couloirs as a result.
Anyway, thanks for the thoughts. My friend is following the thread, I think, and we've had a lot of good discussion around this incident.
Dang Marcus, glad everyone is okay. Sounds like despite the scary emerging circumstances, you guys handled the situation well. Props and thanks for yours and your friends' wellbeing!
Thanks Scott -- just to be clear, I wasn't there, just posting it for my friend. And yeah, I think they did a great job handling the situation.
Hey there....i was the narrator on this TR. Thanks for all the good comments, I find it very helpful to analyze TRs after the fact and learn from other folks' insights. Our group has some descent miles under it's belt: one ex ski patrol from Squaw and the other two have toured for 6+ seasons. Regardless, i think we missed the call on this one. I concluded that the upper slide resulted more from the poor bonding to the slide bed than from wind loading (the initiation point only had 2-3" of new snow). The lower slide is tougher to analyze, but i think it slid on the same layer. It was likely more easily triggered because of it's proximity on the lower edge of the icefall . Interesting note is that both slides were triggered by our snowboarder and a couple skiers exited the Slot at the same time without incident. I have some poor quality Ipone pics of Todd actually in the slide that i'll try to post if i can shrink the files.
Thanks again.
Murray
Thanks again.
Murray
author=Murrmeister link=topic=12514.msg52348#msg52348 date=1236194682]
Hey there....i was the narrator on this TR. Thanks for all the good comments, I find it very helpful to analyze TRs after the fact and learn from other folks' insights. Our group has some descent miles under it's belt: one ex ski patrol from Squaw and the other two have toured for 6+ seasons. Regardless, i think we missed the call on this one. I concluded that the upper slide resulted more from the poor bonding to the slide bed than from wind loading (the initiation point only had 2-3" of new snow). The lower slide is tougher to analyze, but i think it slid on the same layer. It was likely more easily triggered because of it's proximity on the lower edge of the icefall . Interesting note is that both slides were triggered by our snowboarder and a couple skiers exited the Slot at the same time without incident. I have some poor quality Ipone pics of Todd actually in the slide that i'll try to post if i can shrink the files.
Thanks again.
Murray
author=Murrmeister link=topic=12514.msg52349#msg52349 date=1236195686]
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