23 November, 2009

Work - Avalanche Terrain Assessment


Today I had the chance to access the skiing on a snowmobile, while doing a terrain assessment with fellow guides and avalanche instructors Ty Petrusic, Jay Neil, Paul Carus, and Jeff Van Driel.  I rarely use any form of mechanized form of travel, but with the opportunity to ski at work, I couldn't pass it up.

After a quick guides meeting, we were in Callaghan and loading up the sleds, and getting geared up.  The goal for today was a terrain assessment of the Sproatt area.  This winter Canadian Snowmobile will be running avalanche courses for sledders and skiers, so all of us avalanche course providers headed up the mountain to see what ski terrain we could use, and do some safe route finding.  Needless to say we pretty much were just skiing.

After skinning for a while, trying to get up onto some ridge features, and find our line to ski through the white out conditions we were stopped.  On a leeward slope, fairly steep, we began seeing long shooting cracks.  The conditions didn't want our line to go.  Stopping, after some ski cutting, and jumping on test slopes, we dug in to see what was going on.  We found a 40cm slab of storm snow, which was tightening up from slightly warming temperatures, on a layer of tiny surface hoar crystals, decomposing stellars, and needles.  A few compression (CTM16), extended column, propagation saw, and burp tests the picture was clear, and it was saying no steeper skiing. 

We headed back skiing mellower terrain along the way.  Our decision was re-enforced when we remotely triggered a gully, that propagated pretty far, while skiing on the top and opposite side.  Oh well at least the sledding was fun!  Stay safe out there, the snow is just piling more and more, and with the wind, temperatures, storm snow, and other factors we're getting primed for some big avalanches. 


2 comments:

  1. Great site alex! It's fun checking in to see whats been going on. To your readers...to the unintiated eye a rising freezing level will most likey produce some large avalanches.(At least with what we found out on Sproatt.) Rain is still considered new load which is what we are forecast to get, so keep an eye on how many mm we get, it's a good habit too to measure your new snow in mm of water too! What a start to the season....just need to find my 4.5metre probe....

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  2. Freezing level, 2000m tonight (24/11/09), with rain fall amounts 5-10mm, and 10-25cm of snow. Mountain top winds southerly at 50-70km/h. Rain should change to snow in the morning, and freezing level lowering to 1800m, and lowering again to 1500m in the evening.

    Don't worry everyone, it's still just November! Watch that snowpack, and stay safe! More blower powder on the way!

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