Home > Trip Reports > more avalanches in Clara Lakes area 1/31/2016

more avalanches in Clara Lakes area 1/31/2016

1/31/16
WA Cascades East Slopes Central
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Posted by mikerolfs on 1/31/16 11:58am
Reports of avalanche activity keep coming from both the east and west side of Mission Ridge ski area. The latest excitement involves a snowmobile (in the non-motorized area above Clara Lakes) buried vertically, completely buried vertically, at the base of a 70 vertical foot slope. I believe this burial happened on Monday, 1-25, the same day as jtack's Stemilt observation of avalanche of the entire east slope of Stemilt basin.

For interest, jtack and I checked out the site of the snowmo burial on Sunday, 1-31.  The bed slope ranged from 15 to 40 degrees. The start zone where we dug was 19 degrees. The length of the slide was on the order of 300 yards. The crown was only 15cm, but the entire slope slid so the debris pile was significant.

Start zone
under 20 degrees:


The crown measured 15cm after we brushed away this week's snow.


There was a clear ice layer above the bed surface


The Jan5? layer was UNREACTIVE

This layer was the bed surface for the 1/25 avalanche that buried the snowmobile. It is completely un-reactive today. This is the January 5(?)layer.


This layer, 50cm down, was reactive. It failed on 25 and 28 taps. This is the december crust.



This picture shows the excavation effort from last monday. I'm told the sled was buried VERTICALLY. This slope is only 70 vertical feet high.


Here is the current surface condition above Lake Clara:




Above the snowmo burial site, we observed that the entire east facing slope had slid above Lake Clara. Very similar to Jamie's Stemilt observation. I don't know if you can zoom in on the following composite photo, but if you can, you'll see a continuous crown from left to right across about a half mile.



here's something else we saw.  You all probably are aware of this, but it's worth viewing. Looking at my compass I said "the slope is NE aspect". Jamie thought it was closer to East aspect. Here is what we learned from that interchange: https://vimeo.com/153717176
Great observations.  Scary crazy electronic disturbance in the video.

Thanks for answering the question Mike as to whether the rain was substantial enough  to destroy the buried surface hoar...I guess not.  I heard the crust was supportive near Blewett, though, effectively bridging the weak layers from skiers weights. If only temporarily.  Is it similarly supportive at Clara?

Yes. The crust is currently supportive to skis. I think it would not support boots.

Has that area been officially classified as non-motorized now? That's great if so but bad if the sleds are still getting in there.

author=aaron_wright link=topic=35622.msg145792#msg145792 date=1454341615]
Has that area been officially classified as non-motorized now? That's great if so but bad if the sleds are still getting in there.


I don't think so. It was identified in the 2015 DNR winter recreation plan as non-motorized. But the plan also identified a mountain bike trail from Mission to Ellensburg. Just like the trail doesn't yet exist, I think the non-moto designation may still just be a plan goal. I don't believe the border is posted yet. I'm probably jumping the gun by calling it non-moto.

Do we know the folks in the party of snowmobilers?

author=aaron_wright link=topic=35622.msg145796#msg145796 date=1454342733]
Do we know the folks in the party of snowmobilers?


I don't. I hope they report the snowmo burial to NWAC. I'm curious about what happened.

author=mikerolfs link=topic=35622.msg145797#msg145797 date=1454342938]
I don't. I hope they report the snowmo burial to NWAC. I'm curious about what happened.
I looked on the NWAC site, no mention of this as of yesterday in the forecast, observations or accidents.
I'm gonna ask around see if anyone knows who this was.

author=aaron_wright link=topic=35622.msg145796#msg145796 date=1454342733]
Do we know the folks in the party of snowmobilers?


A quick look at Snowest doesn't turn anything up, either.

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more-avalanches-in-clara-lakes-area-1-31-2016
mikerolfs
2016-01-31 19:58:18