Monday, December 23, 2013

Anthony Lakes - Good turns on a shaky snowpack

The next video best describes snowpack conditions at Anthony Lakes:


ECTP at Anthony Lakes July 22nd from Santiago Rodriguez on Vimeo.
Pedro demonstrating ECTP at Anthony Lakes.

Anthony Lakes has always been an option for Boise skiers. Not a bad drive, and just 20 minutes longer than driving to Banner Summit from Boise.

The ski touring at Anthony Lakes possibilities are many. Please refer to the next link for a really nice resource. Caltopo is an incredibly helpful planning tool with its signature feature where slope angles are colored in the topo map. CalTopo very user friendly interface makes easy to add UTM lines, 40' contour lines to the topo map, among other cool features,  as well as to print or save maps.

http://caltopo.com/map.html#ll=44.95129,-118.2343&z=15&b=t&a=c,sg

The next image captures the ski tour we did today in a blue trace, but also shows the interface of CalTopo. Please if you use this tool in a regular based send a 'Thank You' note to the Matt Jacobs, owner of the site or better ... make a tax-deductible donation to Bay Area Mountain Rescue via info@caltopo.com.

Skiing last Saturday at Mores Creek Summit was fun, but Pedro and I wanted ... more snow, and Anthony hardly ever fails to provide the goods. Sunday was not the exception.
Pedro and Jesse preparing for the first run.
The backcountry was covered by a recent coating of  30 cm of creamy and somewhat heavy snow that felt like 12% dense. A combination of factors confabulated to densify the snow throughout the day; moderate winds from the west, heavy moist fog, and temps  hovering near the zero degrees celsius for most of the day. But we rejoiced in not having to worry too much about what lies below the snow. The snowpack depth was around 1.2 meters. Although, we should never forget that we are in the mountains and Anthony is a granite garden, thus we still had occasional contacts with buried boulders.

Today we had a guest with us, Jesse, on his second outing to the backcountry, but first time on a winter ski tour. We always enjoy introducing the winter wonderland to those willing to explore.
Jessy testing his new ski touring gear; splitboard, pack, layering ....
As noted earlier by the video, conditions were unstable. Stability test early in the day produced two CTE-Q1(SP), a CTM-Q1(SC), and ECTP11-Q1(SC). All failures were observed at 45 cms below the snow surface, where a 2 cm layer of facets undermined a fragile decomposing crust interface . The test slope had a SW aspect at 28 degrees test slope at 8100 feet. Below the 45 there was another fragile crust layer also undermined by another even thinner facet layer. The rest of the snowpack was facetty with various crust layer in between.

While skinning up we had numerous whumpfs, where we also remotely triggered a very small avalanche in a steep roll-over. But based on earlier stability results we were only skiing gentle slopes with slope angles under 30 degrees.
Notice the fractures (cracks) and small avi.
Instability was also present at north aspects. On our way back to the car we approached a ridge with North aspect slopes. At Poster Ridge we remotely triggered a collapse with cracks spider webbing across the slope but the slope did not slide.

Mores Creek Summit has a similar structure of fragile crust  layers undermined by well developed facets, but it lacks the 45 cm of snow loading present at Anthony Lakes. And as Pedro stated earlier in Sunday during our drive to Anthony Lakes after observing road cuts with avalanche fractures, the faceting of old snow after weeks of zero precipitation was a regional issue. We should not be surprised to observe similar problems across central Idaho.


Saturday, December 21, 2013

Mores Creek Summit Blog, back at it again!

After months of no activity at Mores Creek Summit blog, we resume our work today. And .... welcome to this year backcountry ski season!

Saturday December 21st, was a sunny day, and a delightful day to be out. After spending the Austral winter in Argentina and Chile, and arriving late to School in September, I was too busy with school and research snow work to be  able to make it to Idaho's backcountry until after the end of school this last Friday.
300 feet above the road, the forest starts to look wintery!
The day started without wind, but at around 6500 feet the snow surface showed clear signs of a significant north wind event during or immediately after Friday's storm. As I continue to gain elevation, the wind scouring/erosion, wind crust, and transport became more pronounced. Later in the day the wind picked up again, and continue to make surface snow conditions less conducive to good riding. Air temperatures remained between -5 Deg C in the morning and up to -2 Deg C in the afternoon.
Almost Top of the world ... the falling snow is a random google effect that just introduced itself.
It was kind of a short day-had to be early back to Boise to pick my son Pedro at the airport. Time was short but I managed to do four runs at each; Top of The World, Almost Top of The World, a quicky line between The Knob and The Summit Glades, to finish the day early with a run from the top of the Summit Creek Glades down to Summit Creek.

There is a supportive crust all the way down to 6000 feet,. With very careful route selection, it is possible to ski down to Summit creek and exit to the road, with some occasional bushwhacking. Climbing up the snowmobile road to gain access to Pilot Peak backcountry skiing is optimal, but I managed to climb up the second ridge to the north of Mores Creek Summit proper without too much difficulty. Again thanks to the supportable crust. This does not mean that the snowpack is NOT shallow, it is boney!. North and Northeast aspects above 7000 feet have 80 cm or so of snow, but East and Southeast aspects have only 50 cms of snow!
Top of The World Snowpack at 7800 feet, 50 cm thick.
The snowpack was not only shallow at all locations, but at all locations there are three distinctive crust layers with a layer of well developed facet below the crust. the top two layers failed easily during compression tests, and are going to be a problem once they are loaded during next storm. The top layers were too shallow to pose a problem to skier at Mores Creek Summit today.

In the morning two other backcountry skiers shared turns with me at Top of the world. Inspection of the picture below shows the snowpit near the top next to my tracks, at a location with 36 degrees in steepness. A black and white picture of the snowpit is shown above.
Top of The World
There were fun skiing, but snow surface conditions were highly variable. Most of the skiing was above a supportable crust covered with little snow to up to 10 cms. At wind affected slopes, a crust made skiing instructional. Occasionally above 7000 feet at north aspects the crust was not supportable and ski penetrated through most of the snowpack. I avoided such locations to protect my skis from damage.

Between The Knob and Summit Glades.

Tomorrow I will be out again, and will be sharing obs for a different location in Central Idaho.

Cheers!