Tag Archive | surface hoar

10/28/12 Thoughts On Our First Layer

Took a drive tour over Loveland Pass  coming back home from the front range yesterday.  Stopped to hike the dog up  the eastside ridge at the summit of Loveland pass.  Stomping through freshness layered in among the scree it was great to get smacked in the head with 0 degree, 30 mph winds under  a cobalt grey sky.Stood into the wind  and took  a breath of the cold. The jet stream was whipping clouds overhead, obscuring the tops of the highest peaks off the Divide,  blasting eastward. Snow was falling and the wind was transporting it  in great swirls on the open faces of the pass, steadily erasing whats left poking through the snow. Off in the distance, A-Basin looked better than it did all of last year, lifts churning on a busy Saturday,  snow in the tress .There were even a few intrepid souls braving seriously early season conditions on the West side of the pass, skiing down to the lower switchbacks . Looked to be about 8 inches of fresh on top of  a  60 mile deep granite base. Admire the love, a little early for myself. Drove over a mitten in A-Basin”s cross walk. coming down the pass.  No hand in it.  Ahh winter. It’s back.. At least above 11,000 feet.

Back in our world, EV is covered in its first layer of the white stuff. I drove back over Vail pass looking   the notorious layer that is the foundation for  our snowpack. Usually for us in Colorado this  becomes a  loosely faceted  layer that sets the stage for an avalanche cycle in mid to late November in EV and can dog us for the entire season,  depending. Last season Old Man’s early season was perfect example, sliding to the ground in November.

This first snow set the stage for the crown jewel of a  garbage Continental snowpack in 2011/2012. Early October snow with a long  long period of  clear, warm weather created  2-4 mm very loose facets out of the first snow. Surface hoar also reared its’ ugly head. When we finally did get some snow, it came with wind and the results….well you remember. The snow pack never recovered.

Our best hope is continued snow without a third Indian summer before the larger snow load arrives.  As bad as last year was ,two years ago was the textbook for a decent  snowpack. fo us. Snow, snow and more snow, consistent temps and little wind. “Average” year ? I’d take it. 

Every year is different and fascinating in our world, , not only because of the endless variables that affect our  snow, but the endlessly variable human element as well.  You can’t make the stuff up that happens out in EV. Keeps me coming back and I can’t wait to tell the tale this year. See you soon at the bus stop. EVI.

EV late October

EV Time Machine

So the snow has fallen and we are on the cusp of the “Full On” EV season. Too many red flags for us to venture back into EV today with the peaks flagging hard and the obvious avi activity in the back bowls off Two Elks.  Took Martin’s advice and rolled up on a perfect powder day in the untouched Beacon Park. Scraped the rust off my single and multiple burial skills and waxed the time to under 3 minutes.  Try and hold your breath for 3 minutes, imagine it being a  lot worse when you/your buddies are buried and counting on each other to rescue them/you in time.

Hopefully, the two groups of skiers that braved the obvious warning signs and B-Lined back to EV or Mushie today are super dialed in. After meeting up with some of the crew, it was a no brainer to let the potential human avi bombs go do their work sans EVI.  Besides, it was a perfect blue day to go rip Colorado’s finest packed pow.

We had a ton of fun ripping the front side and staying out of the danger zone.  Sometimes you have to make your own decision to hang it up.  I ultimately made the personal decision to not risk my season or my life based on my observations and gut feeling on the day.  Tomorrow is another day and you can bet if all adds up to a safe drop, we’ll be back there doing what we do best!

Now that I’m safe and all cozy in my abode, I was digging through some folders and came across some notable pix from the snowmageddon season of 2010-2011.  Just take a gander at these pics from 1/16/2011 and compare them to the pix in the Benchie Pit post… huge difference, enjoy.

Benchmark Pit Report 01/10/12

Tuesday I made the most of the sunny afternoon to shoot up to the top of Benchmark, poke around and see what’s going on back in EV. Skinning out from Two Elk’s, it’s pretty obvious we are no where near the much needed snow pack to get things rolling in the back bowls. I love the sunshine, but seeing a brown-out on all the south facers that were caked deep only twelve months prior is a bit of a downer. Guess the snow is only hanging in the shade and baking in the sun. The slopes are littered with surface hoar, caused by the clear night’s frost and the sunshine baking bonds into weak facets.

Storms like this past Saturday’s is a little more what we could use three times a week for the rest of the month, but let’s face it, what’s here is now… and now we have a pretty weak snow pack.  Studying the avy roses of the CAIC, the weakest areas should lie on the east facing slopes in the Vail-Summit Zone. I decided that’s exactly where I would belay to a shaded 38 degree slope on the NE side of the tall pines that separate East Abe’s and the open east facing slopes of Benchmark.  Reason being, this is most likely where persistant weaknesses will remain throughout this season’s snow pack.

I harnessed up and tied in with the glacier line around a stout tree.  Please be clear, it is not my intention to rope off and start popping off slides on purpose.  A safety line is in every guide’s pack and is an extremely important tool for any back country traveler.  Not to mention, it is the 8th Commandment in Bruce Tremper’s “Staying Alive in Avalanche Terrain”:  “Thou shalt use a Belay rope!  Most serious avalanche professionals carry and use a belay rope.”

I am not an avalanche professional (yet), but I do posses the knowledge and self-preservation skills to have a 30m glacier line as a part of my BC toolkit.  Hopefully it’s a last resort preventative from crack, pop, pin-ball ride through trees and a push off a cliff.

I dug a pit in what could be the sweet spot of a likely starting zone.  During the careful descent amongst sloughing loose snow and little failures of the top layer my observations showed that there weren’t any cracks propagating off into the distance, but the small failures under my skis were enough to be wary of.

Got settled in, dug the “pit” and started to gather some data. There are presently as of 1/10/2012, 3:00pm above 11,400 ft. East Vail Proper, three layers to this shallow 70cm “snow pack”. The bottom 30cm is basically larger facets slightly bonded resting on depth hoar. The next 30-55/60cm are comprised of faceted loose grains and the very top layer 55-70cm is the last storm accumulation. The exposed snow is already riddled with surface hoar. Doesn’t look too great for the future, but some avi cycles are likely to occur with a big snow and flush this particular zone of some of those pesky white dragons for the time being.  The snow pack is constantly changing and this does not mean that those dragons will not creep back into the mix in the future.  So, beware.

An isolated column test resulted in the top 58-70cm layer failing after four shots from the wrist. Not too surprising, while the break was not completely a shear one (Q3). Four shots from the elbow failed at the 30-58cm range, again not a clean break (Q3). Under the right conditions, I’m sensing a collapse in these weaker layers after a good snowfall, or a human loads them.

For the real snow nerds out there (myself included), I measured the temps of the pack to see if there were any major gradients. Chose to use 20cm increments to measure within the noticeable layers and came up with 0 deg. Celsius at 10cm, -1.7 at 30cm, -3.4 at 50cm and -6 at 70cm. Towards the bottom 10-30cm that’s 8.5 deg/m, 17 deg/m in the middle
and 13 deg/m at the top. The numbers below 30cm represent a weak temp gradient (<10 deg. C/m). The rest of the snow pack has a strong temp gradient (>10 deg. C/m), and results in a loss of strength with facet formation.  Math aside, we have plenty of weak snow to make conditions unfavorable in the future.

Cautiously negotiating my away from terrain traps and cliff bands, I skied my way to the lower angled aspect of East Abe’s and made some really fun turns. Crossing the creek and sticking skier’s right, I rode through the deeper shaded snow amongst the short pines until the waterfall. The ride was sugary and mellow. After the falls, the traverse left into the woods and the scarcely packed ski trail was extremely variable. We definitely need some serious snow in those woods to make the ride back to the bus a little less rough. The last bit of the trail is packed down by some snowmobiles and make the last portion along the water tower a welcoming slide home.

Not bad for my first “benchmark to water tower” trip of the year. Grand from afar, far from grand. It will be interesting to see how the snow pack in the zone evolves and how conditions will change as our season trudges on. Glad I was able to take the afternoon for some recon and gauge conditions until the next storm. Until then, keep it safe and pray for more snow!

Mushroom bowls 12/27-12/28

With the holiday crowds closing in, I skinned my way up to Mushie two days in a row to check out the snow on both the West and North aspects in the gladed 20-30 degree terrain for something to do.  The ridge top had variable areas of 10 cm wind board on facets to soft wind blown crust over, you geussed it, more facets, to dirt patches.  The first five upper low angle turns off the ridgeline were decent, fresh turns on stale cake.  As the pitches steepened and rolled toward the cliff band that runs in the middle of Mushroom Bowl, the skiing turned to  a barely covered nightmare of no more than 60 cms of 2mm facets on rocks and fallen trees.  The best way to describe a weighted ski turn  two thirds of the way down is hitting a sandcastle with a baseball bat.  The snow looses cohesion, disintegrates under the weight and the facets run to the dirt in a glittering hiss below the turn.  A frightening prospect for a basal layer for our snow pack when (think positive) our weather  cycle does turn back to snow.

If we continue to get small amounts of snow with long periods of calm weather in between, then avalanche wise it’s really no problem,  it will just be a low tide year for the central mountains like most of AK’s mountains had last year.  However, if we do see an averaging out of the snowfall amounts in the last two thirds of the season, then I have to imagine we will have a signifigant avalanche cycle with the first large dump. With the depth of snow in EV ranging from dirt to sixty cm of loose facets that on both West and North aspects, a two foot dump would rip to the ground with little effort with any kind of rapid loading of typical cold low density mid-winter snow on such a weakly bonded base layer.  Our best hope is precip to come in warm and wet and alot of it.  Or a storm comes in with such rapid loading that EV flushes itself out naturally overnight and cleans out what has become a forgettable early season mess on all aspects.

Something else to check out. Noaa has an interesting report on their website on the effect La Nina will have on Colorado weather for the rest of the winter.  Much of it is super technical, but it is interesting to read the atmospheric science based precipitation predictions for the next six months.  I won’t ruin it for you, check it out and draw your own conclusions.

It was a relief to get out into Mushie and skin far far away from the madnesss happening with the holidays in Vail.   Just passing Two Elk helped my personal holiday decompression. The lack of sno, however trying,  fails to make the skin up to the top of Benchie any less beautiful.  The black, grey and white spattered Gore range, gaunt and bare, stretched into a sky littered with purple and grey clouds streaming in from the Northwest.  A few tendrils of snow stretched down to touch the very tops of the Gore Range, but the wisps were wishful thinking for a range that is now feet away from average.  I enjoyed standing on the top of  Benchie again, wind howling and no one around.   Pretty much ski hiked the last two thirds of the run both days to the road, but I enjoyed the taste of the EV experience that I have, admittedly, taken for granted over the last fourteen years.

11/2/2011 Surface Hoar

Next storm rolled through, dumped  a few coveted inches on top of our much maligned basal layer.  Came in warm, started as rain and cooled off  as the night progressed.  Nice to wake up to the first day of work at Troy’s Ski Shop to snow.  Doesn’t seem right when you’re mounting skis in warm sixty degree weather.   In keeping with the last post, I wanted to address another lurking hazard prevalent in(on) early season snow pack, surface hoar.  As I was riding to East Vail before this last snow, I noticed the fern like crystals stacked up on the snow next to the bike path. Clear, cold skies and high humidity are ideal conditions to  produce these feathery crystals that lie vertically on top  the snow.

Strong in load, but not in shear, these crystals can support subsequent snowfalls until critical stress on the fragile slab is triggered  by you, intrepid backcountry traveler. Surface hoar is hard to keep track of. It can be destroyed by wind in some areas while persisting in others. Even by digging a pit in the locale that you want to ski, it is hard to determine if  buried surface hoar is still present in the entirety of the area you are going to put a load onto by riding. Next time a cold clear night happens with little wind, check around the next day to see if those crystals are around and file it into your never-ending assessment of the growing snowpack around you.

Preseason snow report 10/27/11

Everything is right with the world. Late October and the first of the storms that will constitute the beginnings of our snowpack has rolled through and given way to clear and sunny skies before we get our next storm.  This is fairly typical for the late October snows,  although last year was an anomaly as the snow kept coming and coming.  This year it seems high pressure will build back and temperatures look like they will rise a bit before we return to a storm cycle.   With the clear warmer weather moving back in, it is  important to keep an eye on the snow in the coming weeks.  Without getting covered by subsequent storms,  this first layer can degrade into loose facets, a potential weak layer for future snow to slide on .  Nothing is certain and this is only a bit of early season snow alchemy, but it is backed by my experiences in the past of our Continental snowpack and the effect of this first layer has in East Vail early season. It is one of the hallmarks of or Colorado snowpack, relatively shallow and complex with many different layers and usually a problematic layer at the bottom, at least to start the season, until it either consolidates in the snow pack or flushes out with the first significant avalanche cycle.

Of course we can’t predict the bonding that will happen with extra load until the next storms arrive, and the amount of degradation depends on many factors.  Aspect, temperatures, snowfall, sun hit and elevation are some of major factors that have an impact on the metamorphosis of the snow.  Bottom line, it is a storm and a layer to be mindful of as the season starts to move forward, especially as we get into the beginning of the backcountry ski season in November. As always, rely  your own assessment of the snow.  Just some things to think about from your friends at EVI.

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