Forum Index > Trail Talk > Well goodness, it may snow, avalanche hazard
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gb
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PostSat Dec 22, 2018 6:58 pm 
With the new snow coming people are going to want to get out. But remember areas of the Cascades that have not had a significant amount of deposition over the weak layer may perhaps still be triggered by human travel. These are primarily east of the crest but extend to the crest at Crystal Mountain and likely Stevens Pass above a certain elevation and in many locations like the Teanaway, Chiwaukum, Nason Ridge, and the Stuart Range further east. During and shortly after storms additional loading could also result in dangerous natural avalanches. Crystal Mountain is apparently taking this possibility seriously as they have not yet opened the North or South Back. A friend tells me that they announced on the website that they were using a helicopter to bomb certain locations today that put certain side country runs at risk. They also are warning skiers to stay out of the backcountry in no uncertain terms. This from a NWAC report yesterday:
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Pro Obs December 21, 2018: Matt Primomo Northeast Cascades: Happy Solstice! Today we found more evidence of recent very large avalanches. This one below the north side of Silver Star Peak had crowns approximately 1.5km wide, spanning the steep slopes underneath rock bands of the massif. At all elevations we found persistent weak layers. At 4,000ft this was a thick layer of buried surface hoar. Above 5,000ft this was basal facets. Profile pic is from ESE at 6300ft, showing a generally stable structure with increasing hardness, except for the bottom 20cm. Pic 3 is large grained, striated basal facets found near the bottom of the snowpack at the same location. These were likely the culprit to the recent very large avalanches in the area. Tests showed the snowpack can still propagate fractures at both 4,000ft on N, and 6300ft on ESE. Follow along at www.nwac.us @k2skis @msr_gear @outdoorresearch #cascadeeastnorth #nwacobs
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Professional Observation: December 20th 2018, Ian Nicholson Today while touring out in the backcountry we avoided traveling on and around large open slopes that were steep enough to avalanche. In fact when traveling at mid and higher elevations we made sure to give these big slopes a wide berth because of the highly destructive nature of the current deep persistent avalanche problem. This problem is due to weak snow; a combination of facets and buried surface hoar that exist just over three feet down in the snowpack. These weak layers have been the culprit in several very large avalanches that have been reported over the last few days. While some observations show this layer has been gaining strength, you may still be able to trigger it with large loads or at thinner locations in the snowpack. Any avalanche on this layer would likely result in a 3+ foot deep slab that would no doubt be disastrous Photo: @tinovillanueva sticking to lower angled treed slopes while in Commonwealth Basin on a damp and soggy Thursday. #nwacobs #cascadewestsnoqualmiepass @msr_gear @outdoorresearch @k2skis

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Triton
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PostSun Dec 23, 2018 11:50 am 
gb, I'm assuming one can feel comfortable skiing inbounds say at Stevens???

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christensent
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PostSun Dec 23, 2018 6:45 pm 
Triton wrote:
gb, I'm assuming one can feel comfortable skiing inbounds say at Stevens???
In general it is always "safe" to ski inbounds with regard to avalanches. It is a controlled space. Although people do on rare occasion get injured or killed in avalanches, you are pretty much trusting ski patrol to either make the area you are skiing safe or close the area if they are unable to make it safe. Even in the worst of avalanche conditions, they are out there performing one of these two tasks to ensure safety. So ultimately, yes, you can feel comfortable skiing inbounds at any of the resorts.

Learning mountaineering: 10% technical knowledge, 90% learning how to eat
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gb
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PostTue Dec 25, 2018 8:57 am 
Here is a good summary of the current concerns from the NWAC: https://www.nwac.us/avalanche-forecast/current/cascade-east-north/#photos There appear to be no significant recent incidents (except a 2' slab at Baker yesterday in new snow) regarding the weak layer; which is finally for now and in the absence of storms settling down not only here but also in SW BC www.avalanche.ca The Canadian Rockies and likely some places in the Purcells are the outliers.

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gb
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PostFri Dec 28, 2018 7:43 am 
Along the crest at higher elevations and east of the crest plenty of rain and then snow will increase the avalanche hazard and particularly going east is likely also to once again tick off the weak layer in the period Saturday through Sunday, and continuing into Monday. Because Saturday will suck, that day should not be relevant; but follow precipitation amounts, temperatures and the avalanche hazard ratings and details if intending to go into these areas Sunday and Monday. www.NWAC.us

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gb
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PostWed Jan 09, 2019 9:57 pm 
Although things have gone more normal here - read sucky wet snow and crusts - the weak layer is still creating some excitement in British Columbia and a fatal accident in Montana and another with severe injuries. In those areas (and on the occasions when we experience similar) this is good advice:
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The day before yesterday an avalanche size 3 was triggered remotely by skiers from Molar's ridge. We suspect the avalanche ran close to the ground on the crust buried in late October. We dug on a similar aspect and elevation on Rudi's ridge and got no results on snowpack tests. Digging is probably not an effective way to learn more about this layer. The best way to manage this problem is with conservative terrain choices. We had a good day skiing mellow trees.

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gb
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PostFri Feb 08, 2019 4:23 pm 
New snow after such an awful winter will make people want to go out into the mountains, but the situation is much like it was more than a month ago. Baker may have a better bond at depth and in the short term won't get much new snow (which won't bond). Further south, and especially east of the crest, there may be significant new snow in the near future. There will also be strong winds with much wind transport and cold temperatures that would make any stabilization a very slow process. New snow mostly falls on surface hoar and sugary faceted snow that won't allow good bonding. Underneath this will be a hard layer in many locations (but maybe not east of the crest). This makes a very bad sandwich structure. The new snow will be unstable and avalanche concerns will be dependent on the amount of new snow or snow transport. On the east side even the very old weak layers may once again react depending on the amount of load (new snow). https://www.nwac.us/avalanche-forecast/current/cascade-east-central/ Follow Avalanche and weather information if intending to go out. www.nwac.us

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Malachai Constant
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PostFri Feb 08, 2019 5:42 pm 
WARNING a little appreciated hazard with this snow which is very heavy is that it cause loose branches and detached widow makers to fall from high in the trees. About 10 minutes ago a large one fell in our front yard hooking on the cable. It weighed about 50 lbs and would have been deadly if it hit someone. I managed to flip it off so we can see the shizzshow on local news tonight.

"You do not laugh when you look at the mountains, or when you look at the sea." Lafcadio Hearn
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gb
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PostTue Feb 12, 2019 7:59 am 
An Avalanche Warning is in Effect from Stevens Pass south and along the Cascade East slopes. New snow ranges to 71" at Paradise with winds strong to very strong and certain to have created large slabs. Paradise at Muir had winds to 100 mph yesterday. In most locations this new snow sits on a poor base of either hard or icy snow or sugary, loose grains above a hard surface. East side somewhat protected low to moderate elevation sites with sufficient snowpack may well also have surface hoar from the preceding fair weather regime. Cold temperatures mean slow to essentially no stabilization. www.nwac.us The good news is the snow is mostly stable at Jackson Holes.....and Seattle Golf and Country Club.

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Backpacker Joe
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PostTue Feb 12, 2019 8:49 am 
Some years ago the man who owned the Scottish Lakes High Camp Don was snow shoeing and never returned from the trip. Turns out he was hit by a falling Snow Bomb and it killed him. Don was a great guy. You MUST pay attention to your surroundings. Mal is correct. Be careful out there.

"If destruction be our lot we must ourselves be its author and finisher. As a nation of freemen we must live through all time or die by suicide." — Abraham Lincoln
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gb
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PostThu Feb 14, 2019 5:07 pm 
It is likely to be sketchy for awhile. We need a major cycle and don't look to get one anytime soon. Read the text lower in the forecast: Avalanche conditions at Baker, still risky elsewhere

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PostFri Feb 15, 2019 8:55 am 
It continues to look sketchy. Although the amount of new snow last night was not great, it was accompanied with strong winds for more wind transport and slab formation with gusts in the 50's at Alpental and Baker, and in the 60's at Crystal. The east side is worse with dangerous layering at the base of the significant recent snows. Mention of often wide propagation of slabs is a sign of how sketchy it is. Don't expect that to go away. It is not in the cards. A glance at the Mission Ridge telemetry shows warm air aloft and Eastern Washington temperatures are up today. That will make the upper new snow layers/thin raincrust denser and the entire layer of recent snow more reactive. https://www.nwac.us/avalanche-forecast/current/

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PostSat Feb 16, 2019 10:23 am 
Special Avalanche Warning issued recognizing that Considerable Hazard means that Natural Avalanches are unlikely. It doesn't necessarily mean that the snowpack is stable and can't be human triggered. If you read the various region reports you will note that on the east side <30 degree angles are stressed. https://www.nwac.us/avalanche-forecast/current/cascade-west-north-baker/ Personally, I wouldn't touch open slopes with a ten foot pole!

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gb
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PostMon Feb 18, 2019 3:38 pm 
NWAC:
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On Saturday afternoon on Stevens Pass a party of two snowboarders dropped south into the backcountry off Cowboy Ridge, riding down towards Tunnel Creek. At 5,400 ft on a Southeast aspect, they triggered a D2 avalanche on a 40 degree slope, 150ft wide with an average crown depth of 26”. It ran about 400 vertical feet on facets over a crust, breaking through the crust, and stepped down to facets over another crust a few inches deeper. Both members were partially buried, one up to his his head, the other up to his waist. They were able to self rescue without injuries, and hiked up the bedsurface where they re-entered the ski area boundary. This is as a very relevant near miss. A good reminder that large and dangerous avalanches may still be triggered on this layer of concern.

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iron
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PostMon Feb 18, 2019 4:46 pm 
^darwin award participants. didn't quite win.

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