Friday, December 31, 2010

Freeman Peak - December 30th 2010

Freeman Peak skiing was exceptional today!

We observed numerous D1-D1.5 (small) size crown fractures from the instability cycle that resulted after yesterday storm. Most of the fractures were in terrain features with slope angles in the neighborhood of 36 degrees. Stability evaluation in the area we skied suggested: 'Easy' triggering (CTE), with moderate slip likehood results (Q2), and no evidence of propagation. However, be aware that fracture propagation tests are questionable under soft slab conditions. 

In addition, after a brutal team effort in trail breaking, none of us observed any fracture/crack, propagation, or wumpfs -NO evidence at all of instabilities. Hand pits at various elevations confirmed same results as the snow pit results - the new snow is bonding very well at Freeman on the elevation range (5900-7200 feet) we skied today. But CTEQ2 (X2) results remind us of being vigilant through-out the day, and avoid snow that has become cohesive or "slabby".

Today's moderate winds did not affected the skiing or snow below the 7200 feet with NE and E aspects. The snow at ridge tops developed windslabs, but the wind was loading the SE & S aspects. The only time we observed any evidence of propagation potential was 20 meters or so below an Easterly aspect ridge line with cross-loading. We avoided those pillows.

By the way - it is hard to believe but the recent rain/melt crust is buried 90-100 cm down! Last time I skied Mores Creek Summit Area (Lamar Headwaters) there were 30 cm of pow above the crust, thus at mid elevations the latest storm left behind up to 60 cm of NEW snow.


PS: Erik, Rick, Andy - it was a pleasure to meet you today! THANKS for helping with the trail breaking.

Tuesday, December 28, 2010

Pilot Peak December 27, 2010 - Lamar Creek Slopes

Today I was surprised by the quality of skiing at the headwaters of the Lamar Creek to the East of Pilot Peak. There is not much I can add after you watch this video.


I realize the soundtrack is not a great match, but it was in my mind all day as skinned up and skied down.

I could not rally my sons and friends to accompany me, but I really wanted to tour today the Lamar Creek area. Similar to last Sunday, I had a late start, and it did not helped when the pull-out below the Summit Creek switchback (next to Winter Corner) was not plowed, and I had to get the shovel out and excavate a spot for my vehicle.

The red lines in the Lamar Creek area topo map correspond to the slopes I skied today. The run shown in the video clip are the second through fourth in the clockwise direction.

The green lines are other nice runs I usually ski when I have more time. The terrain at Lamar does not exceeds the 32 degrees of steepness, and with few exceptions besides the nasty terrain traps at the very bottom of the ski runs in red, the terrain can be easily managed when concerned about avalanche stability.

The purple lines denote the "Top of the World" and "Almost Top of the World". Today there were three BC-skiers leaving behind nice looking tracks in that area!

Besides great ski conditions, the snowpack was unremarkable above the 6500 feet at North through East aspects. Below 6500 feet at E to S aspects there was a supportable crust with 30 cm of fun pow, and if you allowed the ski to run free, it was possible to avoid the scratching!


Monday, December 27, 2010

Sunset West Glades - 12/26/2010

After spending Saturday indoors with the family, cooking delicious dishes, playing table games (and loosing every single darn game!), sharing presents, and enjoying each other company, it was time to play outside!

This morning we had a late start. Sunday was an unsettle weather day, after a quick moving storm front left behind 10-20 cm of new snow. The new snow was soft, but heavily "rimmed". In protected aspects the new snow felt in top of 10-15 cm of unconsolidated snow. The slopes with W/NW/N aspect we skied had between 20 to 35 cm of "FIST" hard now that provided great skiing.

The P in the above topo map denotes the pull-out at Freeman peak, and in red the slopes we skied today. The green lines are two other fun lines we did not have time to ski today, but trust me, they are delightful. In blue are the slopes I skied several weeks ago during my first 2010 Winter Tour. The yellow lines corresponds for to ski lines in "Winter Corner". These ski lines are short, but provide great skiing, particularly during short days when time is limited to tour above the 7000 feet level.

The Sunset Peak West Glades are relatively low in elevation (5600 to 6400 feet), and for few years the snowpack has been too shallow to permit good skiing without doing hand to hand combat with the insidious low elevation "Mores Creek Summit" brush stands. Considering that the Mores Creek Summit area snow depth is 120% of average, we gave it a try to the Sunset West glades above I-21, and we found exciting tight lines with knee deep pow.

The video for today's skiing was edited and put together by my son Fritz. Santa Lourdes was very generous this Christmas, and I got a very cool GoPro HD video camera.

The warm temperatures during the last week have resulted in an "nonreactive" snowpack below 6500 feet even when it is stratified, and various facet layers can be easily detected. Stability evaluation at West and North aspects did not reveal evidence of propagation potential (ECTN) and trigger likelihood (ECT & CT scores above 20 taps) results were "hard". The rain crust buried  (20-35 cm) produced "LOW slip likelihood" results with scores consistent scores in the Q3 range. In addition, hand pit tests and several ski cuts on steep roll-overs did not provided evidence of instability. This was surprising, since I was expecting to see pockets of "surface hoar" and/or "near surface facets" buried by the recent NEW snow. Perhaps the conditions at 6500 feet or below did not favored the formation of SH and/or NSF.

It is worth noting that below the 5 cm thick "pencil hard" crust layer there is a facet layer (4F hardness) undermining a decomposing rain crust layer. The faceting of the "rain crust" is being driven by a temperature gradient above 1 degree Celsius per 10 cm below the crust and facet interface, where warmer snow (-1 Deg C) is providing the energy enabling faceting metamorphism. It is a good idea to keep track of this decomposing rain crust layer, particularly at higher elevations (above the elevations we toured today - 6500 feet) where the crust and facet layer might be thiner and/or more reactive.


Wednesday, December 22, 2010

Big Creek Summit - Sunday 12/19

Hi y’all! Hope all your ski adventures are going well, because I know mine are with all this snow! Last weekend I got my first chance to ski since returning from my first semester at UC Berkeley and it was fantastic. On saturday we woke up nice and early to drive to McCall and finish teaching a NSP avy 1 course that has been going for the past 3 weeks. Aside from Chago locking the keys in the car, it went pretty well. The combination of awesome students and instructors made the class a success.

The next day we headed out to Big Creek Summit to get some nice relaxing turns with a group of friends.



Erin & Brad

Pedro & Brad - Munching

Gary, Erin, Bill - getting ready for skinning up.

The snow was great and in most places a supportable rain crust was present with about 30cm of powder snow. Definitely not the day for thin skis, but my JP and Juliens did a great job at keeping me floating at the top. I only wish the same could be said on skin-ups where the elevation change from Sea Level (Berkley) to 7000ft did a number on my climbing speed. Overall a great day fun nice long runs.

As far as the stability was concerned, the name of the game last weekend was variability. During the avy course students conducted snow pits on many different aspects and elevations at Brundage side-country and found a wide range of conditions. The main concerns seemed to be the depth hoar at the bottom of the pack and near surface facets burried about 30cm below the surface. Stability tests and snowpit work at low elevation had depth hoar failure at the bottom of the pack at relatively low CT scores with ECT propagation. At ridge tops the primary factor seemed to be wind loading above a NSF layer. In areas with only moderate wind loading we were recording CT and ECT-propagation scores below 3 taps. In areas with no windloading, the same layer was nonreactive. Unfortunately the instability problems detected at Brundage side-country probably won’t go away anytime soon.

My general interpretation of this was to play it safe especially in areas with windloading or a shallow snowpack. No sense in trying extreme skiing when a good day with friends (and father) are just as rewarding!

Pedro Rodriguez

Sunday, December 5, 2010

Pilot Peak - December 5th

Sunday we enjoyed another day of wonderful skiing at Mores Creek Summit. Saturday I was teaching a NSP Avalanche classroom session, and it felt good to be in the outdoors after spending a full day indoors. Similar to last weekend we parked at Mores Creek Summit summit knowing that we will have to walk back at the end of the day.  I always prefer to ski to the bottom of Summit Creek or Mores Creek, instead of skiing back to the pass. Soon we should receive another 20-30 cm of snow that will ease setting uphill tracks from the lower switchbacks.

Next a picture of the snowcat getting ready to "manicure" the road to Pilot Peak for the snowmobilers.

Brad and Bill with Sunset Peak in the background. The day started cloudy, by noon the sky cleared, the wind decreased from moderate to calm, and the temperatures rapidly peaked above 0 degrees Celsius.

It is worth noting that there were Coyote footprints suggesting that these animals are using the uphill tracks. VERY SMART indeed. Also I applaud the several "snowshoe" tracks I observed at several place during today ski tour. This incredible area should not be domain only of randonee/tele tourers or snowmobilers.

Freeman ridge below with some very nice ski tracks set Saturday!

With all the many touring possibilities at Mores Creek Summit area I rarely return to same slopes a week later, but I wanted to dig a snow pit close to the same location I did snow pit work a week ago (at Top of The World). However, this time Brad performed the stability tests.

Not surprisingly the layer of "Near Surface Facets" (NSF) were the still present at 45 cm below the snow surface. This slope tested has 30 degrees of steepness, a SEE aspect, at an elevation of 7700 feet.  This is NOT a good picture, but the weak layer can be seen halfway in the snow column below the shovel.

The NSF layer produced easy ECT (Extended column Test) and easy CT (Compression Test) scores with Q2 quality. Fracture propagation results were negative, but we noticed that the fracture propagation (ECT-N) was arrested after 45-50 cm.A quick check on structural weaknesses (Lemons) revealed the following:Weak Layer  in top meter - layer of concern at 45 cm.
  • Weak layer consist of "persistent grain types" - NSF
  • Difference between slab and weak layer grain size greater than 1 mm (2 mm  NSF versus 0.5 mm rounds & partly settled grains)
  • More than one step in hardness between slab (1F) and weak layer (Fist)
  • Weak layer thinner than 10 cm - it was ~ 5 mm thick.

So, the five lemons and Easy scores with moderate Q2, clearly suggested prudence, particularly with the warming temperature trend and air temperatures above 0 degrees Celsius. In addition E and South aspect slopes were experiencing numerous "pinwheels" and "rollies" due to the warming trend. Notice the "maximum" temperatures above O degree Celsius from the Mores Creek Summit not only today (December 5th), but during December 2nd and 3rd.

Scan Site Plot

In the long term the warm temps might assist in improving the snowpack structure in the 45 cm interface. The bad news is that we had to manage angles today, and the recent pow suffered from the unavoidable densification and formation of a crust surface at East and South aspects. But as long as you kept your skiing to N/NE aspects and above 6500 feet, the skiing was extremely fun in boot high powder.

I always request my ski companions to allow me to indulge with the great food that can be found at Idaho City eateries. But most importantly, our visit to Idaho City local restaurants supports the local economy! It is the least we can do, after having so much fun in their backyard and playground! Below you will notice the BIG smiles from the Gold Mine Restaurant host after Brad had his dinner delivered after a full day of skiing at Top of The World, Almost Top of the World, and the Knob Ridge areas.

Thanks Dave, Bill, and Brad for a day of camaraderie and friendship!