Tuesday, February 25, 2014

Healthy Snowpack at MCS

The snowpack at Mores Creek Summit is providing great riding conditions for skiers, boarders, and bilers. The snowpack above 6500  at most W, NW, N, NE, and E aspects exceeds 2 meters in depth. Densities for the top meter have jumped for the top half meter from an average  of 17% to 23% in less than a week due temperatures near the freezing level and copious amounts of snow that have favored settlement (densification of snowpack by reduction of air porosity due to the effect of gravity). The current snowpack as well as the higher moisture content snow forecasted for this week will provide a solid base for the early March storms, that will finally OPEN most of the skiing terrain at MCS. Yipee!!!!!!!

Last Friday I spent time ski touring Tamarack's backcountry bowls and doing some research with my "toy radar". The snow was superb!
Tamarack Upper Bowls
Tamarack average elevation for ski touring terrain is lower than Mores Creek Summit, but the recent snow have definitely opened lots of terrain. A lot of the upper bowls get the attention to most. However, there are LOVELY glades and wonderful old forest skiing for those looking for higher quality snow. Remember open slopes are usually victims to wind!

A week ago I was puzzled by a very dirty layer at Mores Creek Summit. I incorrectly assumed it was dirt from trees. But that same layer was also present at Tamarack. Check the picture shared below with a VERY well defined dirty layer.
Tamarack Snow Pit Face - February 21, 2014
Our snow pit work focused in snow science stuff; Radar characterized stratigraphy, Near Infrared stratigraphy, blah, blah, ..., but we looked at stability. No evidence of instability was found, with only easy compression failures with resistant planar (Q2) at a fracture plane 20 cm below the snow surface. Fracture propagation tests were unremarkable at the location we tested.

It is important to EMPHASIZE the nature of the snowpack in our region. We did not find evidence of instability, but we need to be aware of the unprecedented variability of the snowpack at all depths. Throughout our region there are deeply buried PERSISTENT WEAK LAYERS that have consistently shown propensity to propagation! Our thoughts NEED not to be about trigger likelihoods but CONSEQUENCES! It is important to comprehend that deep persistent weak layer avalanches are likely to be unsurvivable, and that significant trauma is a likely component besides deep burial. Furthermore, the highly variable storm temperatures, wind and precipitation rates have resulted in a mosaic of layers buried at the top meter. At Tamarack we identified multiple thick graupel weak layers, and at Mores Creek Summit advanced facets under a crust. These weak layers are in the top 40 cm of the snowpack. There are also reports of random spots of surface hoar, and near surface facets! In summary, there is a LOT of variability ... Be very suspicious of the snowpack, and moderate slope angle selection.
Avalanche crown at Tamarack.
Avalanche crown at Tamarack.
Sunday we covered lots of ground as we skied the South East glades of Freeman into the Twelve Mile Creek. From Twelve mile creek, we skinned up to Rando's Ridge. We covered an excess of 10 kilometers where we did not observe signs of  avalanche activity during the last 3-4 days.
Skinning up to Steve Rambo Ridge
As mentioned earlier in the post, at MCS there is a concerning weak layer consisting of facets under a fragile crust. These weak layer is buried at 25-30 cm of new snow. That layer was present at elevations below 7000 feet. These layer will require attention as snow precipitation events resume later this week.

As you can see in the next picture, skiing even at slopes with South aspect had a high level of entertainment value. The skiing at North and Northeast aspects was exhilarating, with even softer and deeper pow. We selected Sonyas, a north aspect and well protected slope, as the exit ski run. The pow conditions were delightful!
Skiing Freeman South Face.
Enjoy the next set of pictures of strikingly beautiful surface hoar crystals deposited at tree branches:

Last Sunday we had great turns at MCS, but the best part was to watch HOW many folks enjoyed Idaho City recreation resources as well. It was fun to rendezvous with Andreas and Hanna's pod and learnt that they had a great time over Freeman West Glades, and watch Tompton's party hike back to the pass after skiing Pilot's Summit Creek area. I also ran into other Boise State Unversity snow scientists doing research work next to MCS Snotel. And it was super cool to interact with snowmobilers combining snowboarding with snowmobiling ... very cool indeed!

Sunday, February 16, 2014

Pilot Peak - February 16th 2014

Conditions at Mores Creek Summit were better than anticipated. Last Wednesday  we got very very wet after spending 3 hours testing FMCW and GPR radars not too far from the Mores Creek Summit SNOTEL. And it was not raining, it was just snowing but temps were just at the freezing mark. It is no secret that after Wednesday several rain events have occurred at Mores Creek Summit area.

Bottom line - the snowpack depth has increased substantially in a week. Snowpack depths at and above 7000 feet are exceeding the 2 meters! A lot of terrain is opening up ... FINALLY!

Rain runlets were present up to 6600 feet in elevation. The rain event resulted in two rain crusts, one at 50 cms another at 15 cms. The rain crust at 15 cms was fragile, and skis easily broke through. The top 15 cms of snow was low density snow, but the skiing experience was driven by the 15-35 cm layer of heavier density snow. It was fun skiing, but not wasn't the deep low density stuff we skied last week.

A pit profile at 7200 feet with a NE aspect and 28 degrees slope, where the snowpack was 2.35 meters deep revealed the following structure:
Use this link to create your snowpit plots: http://snowgeek.org/tools/hardness-profile
The 35 cm weak layer produced scores of CTEQ2 and ECT11PQ2, suggesting that this layer demands our attention in steep terrain. Easy compression scores with propagation propensity results are evidence of an unstable snowpack!

At various aspects (NE to NW)  and elevations small releases were observed at the 35 cm depth, corresponding to the weak layer reactive during our tests. We did not observed any significant releases, but we were skiing at Summit Creek Glades, where it is not possible to observe avalanche paths or steeper terrain.

Winds were moderate for most of the day, thus it is likely that terrain at the 7800-8000 feet might have some localized windslab in top of the 35 cm weak layer. Pay close attention when encountering windslabs,  or when transitioning to slabby snow with chalky texture. There have been reports by one of the avalanche centers avalanches pulling snow even from nearby low angle terrain.

It should be noted that indications of wet loose releases at south aspects with elevations below 7000 feet were present, but they were more than 24 hours old.

Today temps did not exceeded -2 Deg C. Snow flurries added another 1 or 2 cm of snow throughout the day.

The skiing was lots of fun, with some occasional tricky breakable crust at elevations below 6600 feet.

My ski partner for the day - Mark
Mark first backcountry ski experience at Pilot Peak

Sunday, February 9, 2014

Freeman February 9-2014: Arduous Trail Breaking Day

Another 20 cms of new snow with medium density were waiting for us at Mores Creek Summit after Friday's NEW 25 cms of very light density snow. The temps have been increasing moderately from Friday to Saturday,  resulting in moderately inverted surface snow conditions.

The warming trend and copious amounts of snow made trail breaking arduous this Saturday! Our party uphill advance was considerably slowed down during trail breaking. A ski penetration of half a meter, where the top snow had to be considerably packed heavily taxed us. We were lucky to have a strong party of four, and took MANY turns breaking trail.

You might recall from yesterday's report (http://www.morescreeksummit.com/2014/02/summit-creek-glades-report-for-friday.html) that Friday's 25 cms of new snow came down in top of a 10 cms layer of faceted crystals undermined by a rain crust surface. After this Friday and Saturday precipitation event there is now a 55 cm slab sitting in top of the weak layer that has become reactive at all elevations and NW, NE, and E aspects at MCS. This layer was not an issue at yesterday at MCS  due to the lack of a slab structure at the places we skied, Summit Creek Glades.Today we did not toured South aspects, but is possible for this weak structure (at 55 cms depth) to be present at elevations above 7000 feet.

Extended Column testing at a NE aspect produced easy results with sudden collapse and planar fracture failures through the entire column at a depth of 55 cm; ECTP2Q1(SC/SP). Not surprisingly we experienced many whumpfs, and at steeper slopes fractures were produced. Saturday we restricted our skiing to slopes with less than 35 degrees in steepness.

Visibility was poor making it hard to play with cameras. It snowed all day long with another 5 cms of new snow by the end of the day. Conditions required to let the ski gain speed and use larger radius turns to keep them in the top snow layer, otherwise your speed was kept in check by the inverted snow conditions (light snow under slightly denser snow in the top.)

Enjoy the short video of Eric S. and Steve T. skiing Freeman.

Although the new snow is helping with coverage conditions, lower Freeman still needs another 50 cms to open up the lower chutes and clear most of the brush. Above 6600 feet at North and East aspects there was hardly any brush to deal with.

The forecasted warmer temps will results in rounding, sintering, and settling of the new snow. This will greatly help reducing instabilities in the long term, but it is likely that in the short term there will be a potential of releasing half a meter slabs in steep terrain and avalanche paths that might also trigger the persistent deep slab instability now buried under a meter at MCS. Exercise good judgment and err in the conservative side.

I am hesitant of publicly criticizing Idaho Department of Transportation at Idaho City, particularly when I deeply respect the employees that take very seriously their jobs. It is also understandable for the Idaho Department of Transportation to struggle through major snowstorms along I21 corridor. I also understand the budget restrictions IDT has gone through particularly for this area. But it is hard not miss the degradation in road upkeep between Idaho City and Beaver Creek Summit during the last two winters. And it showed this weekend. This issue not only impacts the snowmobile, backcountry skiers/riders, and cross country skiers community, but also the the Idaho City residents trying to make a living. The mores Creek Summit recreation activity is essential for the prosperity of Idaho City Businesses. But it is important to keep the area not only safe for vehicular traffic, BUT ACCESSIBLE to one of the most POPULAR winter recreation areas in the state. We might be approaching the time when it might be necessary for winter and summer recreationist to join forces to transform Mores Creek Summit to a National Recreational Area.

Wikipedia link for National Recreational Areas

This will greatly help in getting the attention from State and Federal Agencies and better serve the public and nurture the recreation opportunities of Mores Creek Summit.

Saturday, February 8, 2014

Summit Creek Glades report for Friday Feb 7th 2013

Pretty nice skiing with 25cms of new snow, over the last storm 10 cms of new snow, for a total 35 cms of soft stuff (POW) in top of last week rain crust. Even when the snow was low density the rain crust could not be felt.

It was hard not to attempt to go big, with a total of 7 runs from ridge to creek bottoms. Gullies are beginning to get filled, and it was exhilarating to hit them hard in the Summit Creek glades area.

GET OUT and enjoy the backcountry. Who knows when will it be the next time we will lots of soft pow again at MCS.

With respect to instabilities the snow was too soft to be able to perform the standard compressions tests or PST to check for surface instabilities in the top 40 cms. Tilt tests produced easy results at 10 and 35 cms. The 10 cms seem to be storm layer and was active with many little fractures from road cuts to steep slopes.

No evidence of releases for the 35 cm were observed. The 35 cms instability consisted of 25 cms of new snow in top of 10 cm of a faceted layer undermined by the rain crust from last week storm.

We skied mostly N and NE where the snow was not affected by the wind. There were signs of the impact of winds  at places exposed to East and South. Be mindful that we did not observe instabilities at protected slopes with N and NE aspects because we selected terrain that denied a slab structure to the weak layers present at the 35 cm interface. Also, with the new snow forecasted for today and the effects of sintering it is natural to have slab developing above the 35 cm weak layer. Keep an eye on that layer today.

Also, be careful of areas where the deeply buried (80-120 cms) facets could be activated. Deep persistent weak layer instabilities can be activated by new loads, such as the storm cycle we are going thru. I suggest discretion and high level on conservatism at sub-alpine areas ... for example Top of the World, when the last time I checked the avi starting zones are shallower than 1 meter due to wind.

Happy pow hunting Saturday and Sunday!

Sunday, February 2, 2014

Big Creek - Tight tree skiing on February 2nd 2014

My first weekend of February 2014 concludes with ski touring the East side of Big Creek summit, right across Warm Lake road. The west side of Big Creek Summit pass is a very popular destination with lots of options, but the snow cover looked shallow. 

The skiing at the east side of th epass offers mostly N and NW slopes with very tight ski lines , but soft snow conditions made it fun. This backcountry ski area is a good option for families or folks getting initiated into backcountry skiing. Be warned that it is important to be able to handle dense tree skiing, since there are no open slopes and the trees are at times pretty close to each other. Slopes angles are generally in the upper 20s. Most of the skiing is just 400 to 600 feet above Big Creek Summit parking pull-out.

Big Creek high point to the West side of the road.

The rain crust was present at the north aspects I skied, but I was unable to feel the crust while skiing. The crust was only identified during snowpit work. Thirty cms of the latest snow rested above a pencil hard crust formed during the unusually warm days of mid January. During the latest storm two rain crust layers were formed at 10-11 cm and 17-18 cm depths. These two layers were soft, with a hardness at about 1F. A brush was used to uncovered them.
Snowpit at North Aspect at 7100 feet of elevation on a slope with 20 degrees.
The snowpack at Big Creek summit North Aspect slopes with 7100 feet in elevation was 115 cm deep, which is comparable with similar terrain at Mores Creek Summit. However, slopes with South and East aspects looked "boney". at Big Creek Summit. In fact, I noticed a set of tracks skiing into the road below the north side of the pass where the skier hammered his skis against rocks covered by the new snow.
The recent storm snow was not reactive to compression tests. The early December facets now buried at 65 cms did produced evidence of instability:
  • CTHQ1(SC) - 65 cm down (facets, 3 mm)
  • PST30/100(END)Q1(SC)
Check the next video of the PST test:

It could be argued that the stability test performed today at Big Creek Summit was irrelevant. The snowpit did not contribute to any decision taken during these ski tour since slopes are well below 35 degrees in the area skied today. But it also true that the practice of inspecting the snow structure through the winter and spring will enhance the understanding of 'snowpack' instability and its dynamic transitions. This will inevitably improve skills that enable linking avalanche risk with snowpack structures. Quite simply, expertise in snowpack instability can only be accomplished through repeated exposure to snowpit work. The trick is to perform snowpit work efficiently and in the shortest amount of time. As expertise is gained, it becomes easier to select meaningful locations to gain insights about the snowpack structure.

Case in point, careful inspection of the fracture plane revealed that fracture propagation at the 65 cm weak layer occurs along the path with the largest facets. The 10 cm thick weak layer has crystals with an average of 2 mm, but crystals in the fracture plain were 3 mm in size. These 3 mm crystals more often than not formed vertical columns of connected crystals. All facet crystals in the weak layer have rounded to some level, but not sufficiently to initiate sintering and inhibit fracture propagation propensity.

Interesting snow formations due to granite spirals.
Early this morning before heading out of the door I read the forecast from the Sawtooth Avalanche Center, and applauded the advice shared today by Scott Savage:
"This type of snowpack should not be viewed with much confidence or certainty. Where there is a slab sitting on this old structure, you need to select terrain carefully. Avoid steep terrain where there is a slab with consequences."
What is different this year for many of us, is that although we have faced this type of instability when traveling at mountain regions with continental snow climate, it is indeed rare for this buried facets and shallow snowpack to be widespread in the Boise Mountains, West Central Mountains, and Elkhorn Mountains in Oregon.  I understand that some feel comfortable managing the higher risk and consequences we faced this season based in their self-perception of experience. Remember that we rarely have the opportunity to gain experience from rare events, such as the well developed facets buried between 0.5 to 1 meter in our region and that continue to exhibit vigorous propagation propensity during fracture propagation testing.

This season requires to sharpen the slope angle measurement techniques and to THINK consequences of a deep slab releasing on the slope about to be skied. Do not expect to see warning signs ... THIS IS A RARE EVENT!

Superb skiing at Copper Mountain - February 1st 2014

The conditions at Copper Mountain - Banner Summit, exceeded my expectations. Skiing was lots of FUN! And definitely much better than Mores Creek Summit this last Friday.

For starters the rain crust was less evident at Copper. Above 8000 feet, the crust was sporadic and very thin, and covered by 30 cms of new snow.. South aspects had a solar melt crust under the new snow, and all other aspects have a dense layer under the new light density snow.
Views to the South from Copper South Face. Looking into the 1st run I skied.
Views to the Southwest from Copper South Face. Ski tracks from Friday are visible. 
Looking up into Copper South Face after skiing down.
Apparently there were two parties with as many as 3 folks per party (based in their uphill tracks) this past Friday. Today there was only one other guy with a dog at Copper Mountain. I never saw him, but noticed the track he left to skiers left of my track at Copper South face.

The Friday parties labouriously farmed the west glades and the right shoulder of  Copper's south face. No big deal ...  my plan was to ski the south face, drop into treeline, skin-up into the second high point to the East of Copper Mountain Summit, ski the north slopes of this 2nd peak along Copper's east ridge. After skiing 3 short drops into the north slopes, ski the SW slope of the 2nd Peak East of Copper, climb back into copper main ridge, ski a hidden tight line in the West glades, climb back into Copper's mid west ridge, and ski a south aspect slopes until reaching the flats leading to the road. Not a bad day of skiing at all!

2nd Summit east of Copper Mountain.
Ski Lines to the North - 2nd Summit East of Copper. Notice the trees 600 feet down without snow plaster in them.
Copper Mountain Summit
The snowpack 100 feet below the 2nd summit east of Copper was 195 cm deep. The early december weak layer of facets is buried under one meter of snow. The new snow was the only reactive layer with CTEQ2(RP) and ECTN scores identified at this test pit location.
Fist hard near the top, 4F next, then 1F slab in top of Fist hard early December advance facets.
This is the first time in more than a month that I have not  witnessed a whumpf . Furthermore no evidence of nearby avalanches was observed with the exception of Cape Horn south aspects with wet loose avalanches at steep rocky slopes most likely from the wet snow or rain event at the start of the last storm.

Once more, considering the deep persistent weak layer now buried at the 1meter depth, but still reactive, I  did not skied any slopes with angles exceeding 35 degrees. Furthermore my selection was limited to conservative lines.

North aspect slopes about 400 feet below the main ridge did not inspire confidence as the snowpack depth rapidly decreased.  And these slopes surpass easily exceed the 35 degrees! in steepness. Shallower snowpacks with the buried basal facets and steep angles deserve a lot of space, particularly below Copper's alpine terrain with many trees at the avalanche runout zones.

The best ski conditions were at North aspect slopes, but I also found lots of great snow at West and South aspects.
North Aspect Slopes below 2nd Summit East of Copper.
North Aspect Slopes below 2nd Summit East of Copper.
As I skied out of the North back into the SW side of Copper, I enjoyed the views of the ski tracks laid by other folks, as well as the few tracks I contributed to.
South Face of Copper. Chago track is the highest one with the largest turn radius. The track to the skier left was done later in the day as I skied the North aspect slopes.
Chago ski track in the SW face of 2nd Summit East of Copper

As I prepared to do my penultimate ski run, I noticed the tracks to the NW face of Peak 9218. PEak 9218 is one my favorite destinations, but it requires some effort (somewhat long flat approach) to ski its fabulous East aspect slopes.
We call this slope Monkey face - NW face of Peak 9218.
This area is accessed by parking at the avalanche gate.