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gb
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PostThu Dec 10, 2020 1:12 pm 
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The snowpack current prospect is not so hot with a bit of recent snow, a crust below, colder weather with just light snows, followed by larger storms. South slopes would be a hard crust with the light snow prior to bigger storms.
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forest gnome
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PostFri Dec 11, 2020 7:30 am 
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Ya I have warned friends about the HOAR FROST on the surface from sunny weather last week..

Next snow cycle is going to be STUPID DANGEROUS out there!!

& that layer will persist this year.
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gb
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PostTue Dec 15, 2020 8:30 am 
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This will be an unusually dangerous week as poor bonding surfaces and potentially weak snow crystals/grains are becoming covered with progressively deeper and warmer falls of new snow. And add wind for slabs. The slabs would be there even without much wind as the new snow layers build.

Be extra cautious and pay close attention to both avalanche forecasts www.NWAC.us and terrain. Extra caution advised anywhere there is appreciable new and old snow depth and slopes > perhaps below 30 degrees in some areas as this progresses.

https://nwac.us/avalanche-forecast/#/all/

We get a snowpack do-over late Friday/Saturday as rain will likely fall to high elevations. Something like this is common in mountain ranges near the coast but often does not happen further inland as the amounts of rain, if any, are often meager.
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forest gnome
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PostWed Dec 16, 2020 7:52 am 
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Again all that sunny weather with new snow on top of hoarfrost...

Hope everyone is paying attention!!

When I worked at mt.baker we would have the 24hr.rule of letting its settle

Going out early season on top of a huge hoarfrost layer is a BIG NO NO...at baker we learned paitience.
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gb
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PostFri Dec 18, 2020 5:46 am 
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The first complete burial happened yesterday near Mt. Baker. In the South Cascades high winds and somewhat less snowfall make unpredictable slabs more likely. In the North Cascades just because the "snow feels good" does not mean a slab could not be triggered; it would just be a large and fairly deep slab. Along the east slopes basal layers should be substantially weaker and more varied. Action will continue to ramp up with each passing system and a large cycle should happen later Saturday through Sunday morning.

The "Observations" page is a good read for understanding current conditions and also in learning certain things about snowpack and slopes.

https://nwac.us/observations/
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gb
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PostSat Dec 19, 2020 7:02 am 
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Cascade East slopes, moderate to high elevations are the most problematic:

https://nwac.us/avalanche-forecast/#/east-slopes-north
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Downhill
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PostSat Dec 19, 2020 12:47 pm 
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Very important information and links.  Excellent thread, thanks for posting!  up.gif
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ale_capone
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PostSun Dec 20, 2020 7:07 am 
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Seen a nice one just east of Stevens resort. Yesterday morning.  South facing, wind loaded, and slabby. Crown was About 100' and 18"s . most likely natural, but could have been remotely triggered by the one party in front of us. Never seen them, but they went back the way they came.

Was calm and nice weather until we started skiing. Snow picked up, and where was 2"s on my van at 3 pm, and snowing heavily. Hope everyone stayed safe yesterday.
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gb
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PostSun Dec 20, 2020 4:03 pm 
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ale_capone wrote:
Seen a nice one just east of Stevens resort. Yesterday morning.  South facing, wind loaded, and slabby. Crown was About 100' and 18"s . most likely natural, but could have been remotely triggered by the one party in front of us. Never seen them, but they went back the way they came.

Was calm and nice weather until we started skiing. Snow picked up, and where was 2"s on my van at 3 pm, and snowing heavily. Hope everyone stayed safe yesterday.

I haven't looked but you should post that under "Observations" at NWAC.
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gb
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PostSun Dec 20, 2020 8:16 pm 
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The High to Considerable Hazard carries through Monday as very heavy precip once again falls. On the east side is not really known to what degree the really bad layer has been mitigated. It didn't rain that much or that high there and in the North Cascades. With time this recent layer, which fell as dense snow and/or rain, will become a strong bridging layer over the top of the multiple weaknesses.

https://nwac.us/avalanche-forecast/#/all
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PostFri Dec 25, 2020 2:30 pm 
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gb wrote:
The High to Considerable Hazard carries through Monday as very heavy precip once again falls. On the east side is not really known to what degree the really bad layer has been mitigated. It didn't rain that much or that high there and in the North Cascades. With time this recent layer, which fell as dense snow and/or rain, will (may) become a strong bridging layer over the top of the multiple weaknesses.

https://nwac.us/avalanche-forecast/#/all

The weak layers are still lurking in the North Cascades, east side. There is a special bulletin at NWAC for that region.

Unfortunately, given how this last system ended with a new hard crust and subsequent light snowfall, winds, and surface hoar, and near surface facet development during a couple of clear, cool days and nights.....we get a repeat. NWAC forecasts significant snow with very strong winds with the next couple of systems. Hence the bond to the ice crust and to overlying weak layers is not going to be great and fresh slabs are likely - these mainly human triggered. It will depend on the amount of new snow down to the crust or weak layers as to consequences of these slabs. Watch NWAC; hard windslabs on weak layers are very unpredictable and can release extensively.

Don't expect significant improvement into the week of December 27th!
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PostWed Dec 30, 2020 10:05 am 
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Big week this week for avalanches with very large storms and still existing weak layers. This is actually more obvious (because of large amounts of new snow) and hence less problematic than last week's conditions for folks in the mountains.

Still, today, Thursday PM through early (at least) Sunday, large to very large avalanches - most natural after today - are likely to release.  It wouldn't be surprising as this evolves that backcountry slabs could reach 6-10' or even a bit larger, while a ski area incident or two are quite possible. Debris from this cycle should be evident on some early summer hikes in the higher mountains.

NWAC, a really significant avalanche cycle
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Malachai Constant
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PostThu Dec 31, 2020 10:51 am 
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Took a look at NWAC forecast and it is really scary out there. High avy danger west slopes, 14 new snow yesterday, and incident reports at Kendall Lakes and Crystal backcountry, Buried hoar layer. Hundreds of inexperienced people out there to avoid COVID. Be safe stay home and drink.

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"You do not laugh when you look at the mountains, or when you look at the sea." Lafcadio Hearn
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PostFri Jan 01, 2021 7:39 pm 
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This cycle is a really big deal because of very heavy snowfall, weak old bed surface layers, and strong winds. Normally, in a cycle like this the considerable warming (except
East slopes North) and heavy precip last night and in several areas today, followed by a drop in snow levels would mean the cycle would have peaked today. But likely not this time because of a ton of new snow many areas Friday through early Sunday and still rather warm temperatures. Crust refreezing is not likely due to the temps and cloud cover, but some areas with a lot of rain today to a certain elevation likely had a big cycle today. Above 6000' and along the East slope the biggest cycle is likely to be Saturday with whatever large slabs that have yet to rip out, likely to do so Saturday. This can take out old growth adjacent to paths. Regardless of the old layering, the amount of snow Friday night through early Sunday will force yet another cycle in those areas that have already enjoyed a good-sized avalanche cycle in the last 24 hours.

Even valley floors and ski areas may have risk - the latter from large amounts of new snow
Saturday.

https://nwac.us/avalanche-forecast/#/all/

But you can enjoy all this from your armchair as I am because it is way too risky to have any exposure at present. The "Observations" at NWAC make good reading material at home tomorrow. Have some popcorn.
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PostTue Jan 05, 2021 9:53 am 
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This is still an issue as very heavy snowfall continues today. With time the chance of the really big 10' slabs on the West side decreases, but storm snow slabs could still be very large.
Something like a large cornice collapse at higher elevations could still trigger the very big slabs.

East side slabs could still involve a large amount of the total snowpack in isolated instances, but again recent storm slabs could still be quite large.

Continue to pay attention to www.nwac.us

Total precipitation by tomorrow morning at Mt. Baker may reach 18" (precip, not new snow) over the past eight days.
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