Wednesday, December 26, 2012

2012 Christmas Day at Pilot Peak

Another day of great skiing at Top of the World - Pilot Peak! Not very often I go into "Yo-Yo" skiing mode, but today I made an exception.
10 tracks at Top of The World; 2 sets from Pedro and I laid 12/24, 2 from unknown skier 12/25, and 4 from my skis on 12/25.
The ski conditions were quite good. The top 20 cm of the surface snow were low density and very soft due to the formation of near surface facets. Cold temps overnight due to a clear night sky favored radiation losses from the snowpack surface. The cold snow surface (-9 Deg-C) relative to the warmer snow 20 cms below the surface (-6 Deg-C) resulted in temperature gradients in excess of 1 deg-C per 10 cm. These temperature gradients favor facet crystal growth or facetting, thus the snow is less cohesive due to the lack of grain bonds between snow crystals. Facets crystals formation does not result in bonds between crystals, making that type of snow grain cohesionless.

However, the snow between 20 cm and 50 cm at Top of The World - MCS (8000 feet) is progressively settling due its weight and the rounding of snow grains. Temperatures deeper in the snowpack are fairly uniform at approximately -4 deg-C. The lack of temperature gradients favored the rounding of snow precipitation particles (stellars, plates, columns), where rounded particle pack more efficiently due to lower surface area per unit of volume.

As snow precipitation particles are rounded in addition to the constant action of earth gravitation, the grains are "squeezed" closer together. This process is called settlement of the snow, and it is just what happened between december 24th and December 25th, reducing the so much FUN deep ski penetration, or what we like to describe as deep POW skiing. Once the snow grain are in closer contact and in absence of a temperature gradient - then grain interfaces or necks are formed through a process we call sintering. The formation these bonds between snow grains form a skeletal structure that add hardness to the snowpack.

The snowpit profile for Top of The World included below illustrates the progressive hardness of snow from its surface down to the 80 cm depth.

The only layer of concern for December 25th was the buried facet/crust. Stability test results at the 20, 30, and 45 cm did not produce results for ECT (low probability of propagation) with generally moderate results for trigger (CTM) and slip likelihoods (Q2). No signs of instabilities were observed (whumphfs, cracks, natural avalanches, positive ski cuts in steep rolls, ...).

As snow continues to pile up it becomes increasingly hard to impact the facets above a crust buried 80 cm at MCS. This layer structure seems to be more reactive at aspects with a northerly component. Aspects with a E to S components do not produce ECT or PST failures. It is a good idea to continue to carefully monitor this facet/crust layer to avoid being caught by surprise, and have to deal with an angry deep slab with a 80 cm crown!

Enough about snow science ...

Christmas Day at MCS offered great skiing, but there were very few BC skiers/riders. One party headed over to Sunset, and there were two other parties at Pilot Peak side. It is likely that one of the parties was Mark (last year avi l1 student) touring solo, I could recognize his uphill and downhill racks at the hill.

There were some tracks at Almost Top of the World, but the first bowl was trackless. I was surprised about how little visit MCS had during the last two days.
Lightly Tracked - Second Bowl at "Almost Top of The World"
Trackless - 1st Bowl at "Almost Top of The World"
Out of curiosity I decided to ski down a spinal ridge that drops into the Pilot Peak road at 6400 feet. That was a very BAD idea! Below 6800 feet, the brush becomes problematic, and the risk to injury becomes too real. My strong suggestion is to continue exiting via the Pilot Peak road, after skiing down through Pilot Peak South Meadows above 6800 feet of elevation.

It will take at least another half a meter (1.5 feet) of dense snow to make skiing viable through all of the routes we like to ski down to the pull-outs where we park our vehicles.

I realize the Pilot Peak road is currently somewhat "instructional" for BC skiers/riders during downhill riding due to the snomobo trenches, tracks, and bumps, but it certainly beats the hazardous brush. However, I know Greg (groomer for the snowmobile association) will read this note and will be more than happy to groom Pilot Peak road ASAP.

Feliz Navidad!

Monday, December 24, 2012

Tights to Waist deep shots at Pilot - December 24th 2012

What a splendid day to ski at Mores Creek Summit. There was between 20 to 30 cms of new snow depending on elevation.

The day was cold with temps in the -6 to -7 Deg-C, with Light to Moderate winds, and variable sky coverage fluctuating form blue bird in the morning, to cloudy or obscured most of the day. The light winds and cold temps kept the snow soft throughout the day.
South Aspect meadow above 7400 feet - skinning to Pilot Peak 8100 summit.
'We had a slight delay early in the morning ... we started to shovel snow from Mores Creek Summit (MCS) parking lot so that we can safely park away from the road, but we were very LUCKY today ... An IDT snowplow drove by, took mercy on us, and plowed a section of the summit parking. On behalf of all backcountry skiers, we want to express our heartfelt appreciation to IDT and its plow drivers for the fine job they do to plow Idaho-21 pull-outs in the MCS corridor. Without their work, backcountry winter recreation at Mores Creek Summit would NOT be the same!

We skinned to Top of the World, East of Pilot Peak Summit, and again we were very please not to find any evidence of instability. Two days ago the same area showed alarming propagation likelihood results in a buried crust layer with facets above it. Stability analysis for today did not show fracture propagation propensity. The buried crust/facet combo layer resulted in CTHQ1(SC) and ECTN scores. The new snow from last night storm increased the depth of the crust/facet layer from 60 to 70 cm deep in an East aspect slope, 7800 feet in elevation, and 21 degrees steep.

I agree with the Sawtooth Avalanche Advisory for december 23rd and 24th, where the forecasters caution about the unpredictable nature of buried facets above crust layers:

In the Soldier Mountains, Simon noted a concerning snow structure and poor stability test results on a layer of large faceted snow crystals sitting on top of a hard ice crust about 3' deep on some generally northerly slopes at various elevations. Over my career, I've learned to never trust a crust+facet combination when it receives a rapid load; exercise caution where this snowpack scenario exists.

The latest snow pit with negative propagation results was located less than 30 meters from the snow pit that produced positive results two days ago. The snow pit for December 24th lacked a steep temperature gradient at the facet/crust interface, while the snow pit for December 22nd had a significant temperature gradient at the same weak layer interface. And we must ask; Has the gradient decrease during the last two days (temporal variability), or it is the result of spatial variability in the snowpack? Pedro and I assumed that the reactivity of the facet/crust weak layer is driven by the continue formation of facets (crust decomposition), and that spatial variability in the snowpack is responsible for localized areas where temperature gradients exceed the critical 1 deg-C per 10 cm. In other words, we have a snowpack with weak points, and we need to treat it with a respect.

As we ski toured and skied, we diligently searched for evidence of instability, but none was found today. Ski cuts in steep slopes, hand compression tests, and snowpit work (with ECT and CT) were unremarkable, with the exception of the sudden collapse (Q1) at the 70 cm facet/crust layer buried 70 cm. It is hard to trigger this deeply buried layer that does not seem to be able to propagate at the slope we evaluated it today. But considering the high consequences of triggering a 70 cm slab, we recommend BC recreationists to continue to carefully evaluate steep slopes above 7200 feet you intend to ski at MCS.
Stability Wheel
The stability wheel suggest that even though there was today a low likelihood for triggering and propagating a slab fracture, there is a concerning structural weakness buried 70 cm deep. This weakness is failing as a sudden collapse. One strategy is to manage the terrain such as to avoid areas where a trigger likelihood will increase; for example seek uniform slopes with no stress concentrators and/or that lacks shallow pockets. Another strategy is to avoid steep terrain or steep starting zones with slopes angles above 35 degrees until the 70 cm crust/facet becomes resistant planar (Q2) or broken (Q3).

Back into snow riding conditions. The strong winds that affected many areas in Idaho, had a minimal impact at MCS. The snow conditions were soft at all aspects, and very few locations developed wind slabs.
Top of the World - Very Sweet turns!
Pedro shows in the next video how FUN the skiing was Pilot Peak today.

Earlier in the day, my youngest son had fitting problems with his snowboarding boots, so he sitted a couple of runs. He relaxed on a fire in top of the snow, as Pedro and I skied.
Small fire.
Bigger fire.
Fritz is a talented photographer - he got these cool pics from the fire.

During our skin up it was nice to run into friends such as Ralph going for a quick fix, and Alfred touring with his family. There were close to a dozen other BC skiers at MCS recreating at lower elevations.  In contrast, we were alone for most of the day at Top of The World until early in the afternoon we ran into two snowmobilers, Gary and Roy. These two gentleman were very friendly, and I thoroughly enjoyed talking to them. Gary highlighted that he carries a portable sled in case he has to help extract an injured skier, snowshoer or snowmobiler. Kudos to Gary for his initiative!
 Farming the snow at Top of the World.
Pedro -in the vicinity of a large conifer (in the background) with its uphill side bark missing. This large tree was in the middle of  last year D3 avalanche path that ran at Top of The  World. Impressive how HIGH the avalanche impacted the tree.
Too bad we had to leave somewhat early. Fritz and I had to cook Christmas Dinner. Tomorrow evening is Pedro and Lourdes turn to cook dinner. Below a short video clip as we drop into Pilot Peak road.

The snow depth at elevations below between 6000 to 7000 feet is increasing, but the current ~50-60 cm at 6000 feet makes challenging navigating brush at lower elevations. Most BC skiers skinned and skied today down through the lower elevation brush. However, I am sticking to Pilot peak road until MCS Snotel station reaches the 36 inches of "settled" snow height level.

Saturday, December 22, 2012

Surprising Snowpack Changes at MCS - 12.22.2012

John and I toured North East of Top of the World and skied into the headwaters of Whoop Em Up creek headwaters. It was evident that a pod of skiers toured that same general area either Thursday or Friday, leaving behind their tracks.

It has been now a full month where skiing at Mores Creek Summit (MCS) is accessed via the Pilot Peak road due to low snow below 7000 feet. The great news is that skiing continues to be quite good at all aspects above 7200 feet. Although tracks are present in most of the popular ski runs. For those willing to explore, there are plenty of untracked nooks and fun lines waiting for you to track them.

Lunch at the bottom of Whoop Em Up Steeps; John, Chago, Cal, Mark - Left to Right.
Lunch at the bottom of Whoop Em Up Steeps; Cal, Mark, Chris, John- Left to Right.
I was REALLY surprised when early in the day, as we reached the 7800 feet level we experienced a pretty significant whumphf. That is a sign of fracture propagation. We ran into another party of friends that experienced whumphfs as well.

To be honest, I felt like discounting the observation, particularly when last Wednesday there was no evidence of propagation propensity. Stability testing at a North aspect as well as South East aspect, both at 7800, confirmed that the snowpack has changed from last Wednesday due to facet metamorphosis above the buried crust layer. Steep gradients were identified at both snow pits above a buried crust.

The SE aspect weak layer above the crust is buried 60 cm from the snow surface. This same weak layer was found buried at 45 cm at a protected location with North aspect. It is worth noting that SE aspect slope we evaluated is in a slope susceptible to wind loading.

Below a short clip for a PST (propagation saw test) in a slope with SE aspect, at 7800 feet, and a steepness of 26 degrees. The weak layer was buried 60 cm.

ECT results were conflictive, but PST testing clearly suggested a propensity for fracture propagation after cutting 20-30 cm on a 1 meter column. I tend to never put all my eggs in a single basket, and I have been playing with an ECT column where the saw is use to initiate a fracture (similar to PST). Check the next video for the ECT without compression taps, where a saw cut is used to nucleate a fracture at the weak layer buried 45 cm in a slope with North aspect, 7800 feet of elevation, and a steepness of 36 degrees.

Compression test results resulted in CTMQ1 (SP -Suden Planar)  scores at the North Aspect 45 cm layer, and CTMQ1(SC - Sudden Collapse) at the SE aspect 60 cm layer.
Stability Wheels: Integration of Avalanche Mechanism Likelihoods and Structural Weaknesses
Stability Wheels (see above) are great visual tools to visualize instability leading to avalanches. Notice that slip and propagation likelihoods are HIGH, and that structural weaknesses (Lemons) are concerning. The trigger likelihood are moderate, which basically means that all it takes is to find areas in the snowpack where a fracture nucleation can be easily triggered due to shallower snowpack, facet garden, stress concentration, loading, or other possible factor. Since several whumphfs were experienced today,  that is clear INDICATION that triggering is possible at the right spots.

In the meantime, we have a storm heading our way that can possibly increase instability and make the buried weak layer above the crust (45-60 cm) more reactive.
John getting blasted by Snow at Pilot Peak
About 6 cm of new snow fell today. The probabilistic models are calling for a 70-80% probability of more than 10cm for December 24th and 25th. depending on the rate and totals, the buried weak layer might become reactive. Please - Please - Please manage your angles during the next few days and carefully evaluate slopes you intend to ski.

Friday, December 21, 2012

Sargents Mountain - 12.20.2012

Today was another cold day with temps in the -8 to -6 Deg C and moderate winds at Sargents Mountain. Sargents mountain is a popular destination for backcountry skiers, and is located due east of Brundage Mountain Ski Resort.
Dave Bingman - Payette Avalanche Center Director and Lead Forecaster
Early in the morning I had my first BSU-Geophysics research related meetings with a good friend, Dave Bingman. Dave is the director and lead forecaster for the Payette Avalanche Center (PAC) in McCall. We identified research initiatives that will help PAC with forecasting, discussed avalanche education needs, and toured Sargents to get a pulse on the constantly changing snowpack.

The next set of pictures summarizes the conditions: Wind Affected snow at slopes with due West, East, and South aspects!
Raised skin track - wind removed unpacked snow of the ridge.
Snow surface sculpting
Raised pole plants - where did the snow go?
The alpine terrain was getting hammered by the wind today. Check the massive plumes we could see from miles away.
Sawtooth Peak - I think ... not sure!
Not surprisingly, stiff and brittle wind slabs could be easily found.
Snow fracture under my skis.
Dave got his own crack.
The snow quality was not espectacular due to the wind effect, but scattered pockets of soft snow can be found at mid-slopes with the protection of timber. Regardless of the skiing, the views were striking!
Black Tip in the center @ Payette River Mountains.
Nature Window - sculpted from snow and rime.
Agent Orange!
We had a grand time today while looking at snowpits at SW and N aspects. The two snowpits were remarkably different with a 70-90 cm deep dense snowpack at 7800 feet elevation SW aspect slope and a 3 meter deep snowpack at 7800 feet elevation North aspect slope.
Search probe fully buried at North Aspect slope - 7800 feet
I was surprise also how much different the snowpack structure from Mores Creek Summit, Sargents, Angels Basin - Antony Lakes, and Copper Mountain during this season. Sargents snowpack is significantly more complex than the other regional snowpacks, with a multitude of crust layers and temperature gradients. The snowpack depth versus temp plot for the SW snow pit shown below. Notice that the critical 1 deg-C per 10 cm exceded through its width. very likely these gradients will continue to decompose the various existing crusts. This is a concern, because it is possible for subtle facet layer do develop and become reactive later in the season - definitely not good!

The top 1.5 meter - a much deeper snowpack for the North Aspect is illustrated in the next picture.
North Aspect snowpack at Sargents
The snowpack is fairly progressive from Fist to 4 fingers to 1 finger. However, crust layers were identified at each of the transitions of hardness changes with weak layers consisting of facets, mix grains, and decomposing crust crystals.

Compression tests at the N aspect snow pit produced easy triggers with Q2 scores at the 25-30 cm depth. Compression results at other depths with weak layers were unremarkable. However, there was a layer at the 70 cm that did not inspired confidence, due to its rate of crust decomposition where facetting is active above and below the crust.

The recent wind events, early season variability in snowpack depth and structure, as well as  crusts stratigraphy will demand that we carefully evaluate any steep slope we intend to ski!

Once more, PLEASE PLEASE PLEASE check the area avalanche center forecasts before heading out:

Payette Avalanche Center Advisory

Sawtooth Avalanche Center Advisory

And I would greatly encourage for readers of this blog to submit observations to each of the avalanche centers.

During the last weeks avalanches within resort boundaries have buried skiers and riders:

Crystal Mountain Burial - Witness Reports

Seattle Times - Woman Buried at Crystal Mountain

Schweitzer Avalanche - Two Buried

Two Killed by inbounds avalanche in Tignes-France

It is a good idea to wear your avalanche transcievers, and carry your backpack with avalanche rescue gear if you intend to ski inbounds steep terrain, particularly after a snow precipitation event. Also, remember to have a SKI BUDDY! You need somebody to recue you.

Wednesday, December 19, 2012

Pilot Peak - December 19 2012

What a FUN day at Pilot Peak! Pictures are worth MANY WORDS, the next easily summarizes our day.

A friend laying tracks next to mine's at Top of The World
It is hard to beat a day with pleasurable skiing conditions in the company of my son Pedro.

Pedro near the bottom of Top of The World.
I wish Fritz could have made it. Below a short clip of Pedro enjoying himself at Top of The World bowl - Pilot Peak.

There were other parties ski touring Pilot Peak, but we were pleased to run into one of my peers, Scott a BSU Geophysics graduate student. Same story as last week, all parties used Pilot Peak road to reach the 7000 feet level, when there is sufficient snow to leave the road and skin up to Pilot Peak North and East aspect ski runs between 7000 and 8100 feet.

Brian and Scott - above Almost Top of The World
Needles to say, we skied in soft and creamy conditions. The top 30 cms consisted of a thin layer of surface hoar (SH), with copious amounts of "Near-surface" facets (NSF) and decomposing stellar/fragmented precipitation crystals below the SH. The conditions were typical of cold faceted grains we call recrystallized snow.

Snow surface temps were in the -12 deg-C. The recrystallization of precipitation particles is the result of steep gradients (warm snowpack underneath the new snow and cold temperatures). Snow surface gradients were measured in the 2.5 Deg C per 10 cm, higher than the critical 1 deg c per 10 cm.

Check some of the pics of fragmented/stellar, SH and NSF crystals taken today at Mores Creek Summit (MCS). You had to go deep in the snowpack to fid round grains!
3 mm grid
3 mm grid
1 mm grid
During our stability evaluation we did not detected any evidence of instability. Stability testing at Top of The World and Almost Top of The World were consistent with ECTN and CTMQ2 scores for 30 cm and 40 cm layers at NE and E aspects at 7700 and 7900 feet of elevation respectively. These results suggest a low propensity for fracture propagation with a moderate Trigger and Slip Likelihoods. During our touring we did not find conditions (Wind loading or isolated pockets of shallow/facety snowpack) that would have reduce Trigger/Slip likelihoods to High (CTE + Q1). However, the snowpack is still young and has a relatively shallow depth of 135 cm, requiring careful observation and scrutiny as we toured Pilot Peak.

Early in the morning, we observed at lower elevations graupel.

But some of the graupel showed marvelous surface hoar formation - SUPER COOL! Check the next pictures.

As we climbed up Pilot Peak road, close to a dozen of snowmobilers went by us at various times. With the exception of two snowmobilers w/o backpacks, all snowmobilers carried backpacks with shovel and probe, and half of them had SnowPulse air ballons. I was happy to see so many of them with rescue gear!
Top of the World - Six set of tracks from left to right from our party of 3. Rowdy Pedro did not conserved snow with his large radius turns!

Wednesday, December 12, 2012

12.12.2012 Conditions for Pilot Peak

Today was a chilly day with light to moderate south winds at Pilot Peak. The temps hovered around -3 Deg C at 7000 feet to -6 Deg C at the 8100 feet level.

The snow continues to be thin between 6100 to 7000 feet, although there is now enough snow at Pilot's Peak Road to make skinning and  skiing viable from I21 without having to hike. The great news is that today, the road was groomed! This will compact the snow and create a dense base that will allow snowmobilers and skiers alike to use the road  until we have more snow in the ground for the first 900 feet above Mores Creek Summit (MCS) Pass.
Grooming Pilot Peak Road.
As I prepared to head up, the groomer for the snowmobile association arrived to MCS parking lot. We talked for more than 30 minutes about the many reasons all MCS winter recreationists needs to stick together. He shared stories about the times when snowshoers have been rescued by snowmobilers. I highlighted to him, that a backcountry skier/riders rescue chance of success greatly increases by having acces to snowmobiles from nearby motorized recreationists. What a nice person Greg is. I hope he likes beer, because I would love to buy him a beer and a tasty homemade pie at Trudy's in Idaho City!

The chat with Greg gravitated to the love we share for the Idaho outdoors, and talked about threats to access to the resources we depend so much to fill our souls. Under today's difficult economic climate, state agencies are being challenge to meet the needs of MCS winter recreationists with limited budgets. For example, the plowing of the parking lot at MCS cost money, and there is uncertainty as to what agency or organization is responsible for its upkeep. As you can see this is very concerning, when if for any reason the MCS parking and/or pull-outs are not plowed, we skiers/riders/snowshoers and we snowmobile riders will be unable to access the wonderful recreational resources we have come to love so much.

Greg doing his magic grooming.
Anyway, Greg had to go, and I had a limited number of hours so we both headed up to the snowy hills. At the 7000 feet level, snow depths precipitously increased. At Pilot Peak Lookout, the snow was 165 cm deep ... not bad for at all.
Pilot Peak Glades below the Lookout
Views to the North-East right below Pilot Peak
It was nice to observe that the top 60 cms of the snowpack with due north aspect at 8100 feet do not have a strong gradient at Pilot Peak That explains the presence of mixed grains and rounding of facets at the 25 cm  and 30 cm weak layer interfaces. No evidence of propagation potential was found with ECT and PST tests. The easy compression test results and "sudden collapse - Q1" are signs that caution and good decision making are required for the current conditions at MCS north aspects . No other  signs of instability were observed today, but visibility was very limited.

Time was limited today, I had to be back to Boise to pick Pedro (my son) at the airport. But I played for few minutes with some geeky stuff, before skiing back to the road in velvety snow conditions the low angles meadow slopes with south aspect.
Measuring humidity inside the snowpack
Rimmed snow at the Pilot Peak Towers

Tuesday, December 11, 2012

Hero skiing at Copper Mountain Dec 9th and Registration for AVI L1 Course

My friends, I am so sorry for not being able to visit the backcountry and share my observations during the last few days. This weekend I was refreshing my wilderness medical skills, while report after report of superb skiing conditions kept my e-mail in-tray & FB messages active. And the video clips looked awesome. It was just plain torture!

First, one of MCS blog readers need your help. Chris left his BCA snow saw at Pilot Peak last Sunday. Below the description of the location he thinks he left behind the snow saw:
A group of us were up at MCS and Pilot Peak yesterday (Sun, Dec 9) and I left my snow saw at the top next to the pit we dug. It's just directly north of the lookout building on top of Pilot's about 10 meters down into the bowl. 
We skied that Lookout Bowl shot pretty much directly behind the lookout building & then traversed over to the west (skiers left) to regroup where there was a bunch of snowmobile tracks. There's a chance it could have been left there too. It's a 35cm BCA saw w/ a black handle. 
Hoping someone might be able to grab it if they're heading up there & I can come get it from them later. 
Contact number is 208-631-0577 or
Reports for MCS above 7000 feet was of 15 cm of light snow in top of last week crust. The reports for Banner summit could have not added more positive adjectives! And no sign of instability were detected at MCS or Banner Summit.
It was unbelieveable! It's a whole different world above 7000 feet. We went up on Sunday (December 9) and it was even better. It was 9 below F at the highway with a few inches of new (white smoke) on top of some heavier snow Bluebird day! All good!!
Michael Lyons shared the following picture for Sunday's spectacular day!

Winter Wonderland at Copper
Check this video from my friends Evan and Greg - it is HOT!

Pedro (my son) and I decided to share a holiday gift with the backcountry skiing community and open an AVI L1 course scheduled for December 28th, 29th, and 30th. There are no fees for this course, but it will be expected from participants to volunteer a minimum of 3 days at one of the many Idaho non-profit organizations. I will work with each of you to find the optimum match.

This course will have limited spots. Female skiers/riders will be prioritized during the registration to skew the distribution to 50% of female participants. In order to participate in this avalanche course we will required that you come to the course with; 2 or 3 antennae avalanche beacon, 3 meter avalanche probe, metal shovel with extendable handle, a sight-through compas/clinometer, snow saw, ski touring (or split board) gear with skins, and own Snow Sense 5th Edition. You will have to bring the gear to the classroom session at my home December 28th. The field sessions are scheduled for December 29th and 30th. The location will be determined during the classroom session.

The link for the AVI L1 course registration is:

AVI L1 Registration - Dec 28, 29, 30 2012

We continue to receive a lot of valuable information from devices interfering with avalanche beacons. Check the next video for a cool experiment folks did with a GoPro. To the readers of the blog, please check your electronic gear to determine what is your exposure level due to electromagnetic interference. And remember that is a good practice to keep electronics at no less than 30 cm away from avalanche beacons, and if possible have gear like phones in "airplane mode".

Finally, the Payette Avalanche Center (PAC) and Sawtooth Avalanche Centers (SAC) would love to receive YOUR observations. PAC are interested in observations for our neighborhood, such as Mores Creek Summit, Big Creek Summit. For observations at Soldier Mountain and Banner Summit backcountry, please-please also share those observations with the SAC.

Payette Avalanche Center - BC Skiers Observations Link

Sawtooth Avalanche Center - BC Skiers Observation Link

Happy Holidays!

Monday, December 3, 2012

Early December 2012 Storm blessed Copper Mt

Admin Edit: Due to maintenance, there will be a brief outage between 12:05AM Dec 7 going to the early hours of the morning (about 6AM).

After a busy Friday & Saturday preparing for an AVI L2 classroom session to be delivered this past Sunday, I was desperate to get out and check the impact of the 3-day Early December prolific storm.

It was disappointing to drive through Mores Creek Summit and see very little snow at the pass. Reports from friends that skied Pilot Peak last Saturday were favorable. Similar to a week ago, hiking up the road for some distance is necessary to get off the dirt and into snow deep enough for skinning. The best skiing is at the top 500 feet of Pilot Peak.

The drive up the canyon on I21 revealed shallow snow coverage, until just prior to Banner Summit (7000 feet), where the snowpack showed very distinctive rain runlets!

Once we got closer to Copper Mountain, snow amounts rapidly increased. From the base of Copper up to 7500 feet there was a burly rain crust below a variable layer of 10-15 cm of low density snow. Above 7500 the rain crust vanished, and the snow started to feel really good!
7800 feet - Indication of significant settlement in the snowpack
The morning started somewhat cold (-8 Deg-C) with light winds, stayed at - 5 Deg C for most of the day, but warmed to -3 deg-C late in the afternoon. Changes to the snowpack were noticed thorough-out the day due to settlement. Trail breaking was a chore for most of the day, but as the snow proceeded to settle it became increasingly easier.

Snow pits at 8200 and 8400 feet, at the top of Copper's west open slopes, produced moderate CT results (CTMQ2). No indication of propagation propensity was found (ECTN) at the snowpit locations. Weak layers reactive to CT testing were identified at 45 cm and 60 cm, with sluggish sudden planar scores that could have been classify Q3. CT were repeated 3 times, and with one showing a clear Q2 score. Both weak layers were composed of stellar/dendrite precipitation crystals in the 1 mm size range. It is reasonable to expect that those two weak layers will bond within the next 48 hour.

Below two videos. The first for the a compression test (CT), and the second for a loaded CT. The concept behind the loaded column test is to simulate the effect of loading.

Next the loaded CT test.

The effect of wind loading as well as wind scouring was evident at the 8600 feet level. We treated with respect west slopes above 8000 feet that were loaded mid slope,  as well as slopes that experienced wind scoured at their starting zones.

A BIG concern as we ski toured, was a slope at the 8650 feet that was sufficiently wind scoured to expose rock (where usually we see none) right at the convexity in a starting zone - it did NOT inspire confidence at all!. We assumed that this could be a thin spots with the potential of a higher likelihood of triggering a slide at the deeply buried basal facets or buried parlor of facet/surface hoar crystals observed a week ago. In addition, we avoided slopes with angles above 35 degrees considering the spatial variability (wind effect  and early season) as well as significant precipitation event during the last 72 hours.

Views to the Sawtooth to the East of Copper
Copper Mountain South Ridge
The coverage at Copper is fabulous, there is snow everywhere! The snowpack depth at the 8400-8600 feet level was 1.5 meters.

Eric getting ready to ski the last lap of the day.
Eric (tiny dot) getting ready to ski down for his last run of the day - Copper South Ridge into South face.

During the day we travelled and skied slopes with the most fluffy snow or that were minimally impacted by the strong winds from the last storm ... and the skiing was phenomenal! At the end of the day, in lower angle terrain, I filmed Eric enjoying himself.

Today was a superb day, and I was pleased not to be skiing in my rock boards, and instead with my pow tools. It has been a long time, since the last time I skied conditions this good the first week of December.

One more cool observation - we noticed below the 7000 feet level downhill from Banner Summit's avalanche gates, two small road cut slopes where tree fall appeared to have triggered small slides ... but we are not certain. This might be a good time to REMIND readers NOT to park between the avalanche gates! Public parking is NOT allowed between between the Granjean and Banner Summit section of Idaho-21.


Next is an addition to the post after it was originally posted Monday night 12/3.

A good friend, Evan, shared the next update and pictures from Pilot Peak from last Sunday - December 2nd:

Thought I would share some things we saw at pilots. Most aspects were devastated by wind and what seemed to be a rain event. North facing aspects were more so very wind loaded without the super hard crust. Lots of natural activity occurring on east and north slopes. With a weak layer releasing around 30 cm down from what I guess to be a combo of wind loading and warming. Great day of touring and recon. 

Cracks in the snow.
Avi below Pilot Lookout.
Avi at Pilot Peak.