Thursday, December 29, 2016

Winter Corner - December 28, 2016

Wednesday we visited Winter Corner to enjoy 15 cms of new snow and to see first hand how the landscape has changed after the Pioneer Fire.
Winter Corner Burnt Forest
Winter Corner offers great riding options that are not obvious from Idaho 21 road. There is enough terrain to keep several parties entertained on a pow day. From its west slopes, spinal ridges, snow filled gullies, natural freeskier "trick" features, and mellow dead north runs Winter Corner that surprises with its ample opportunities to explore.
Splitboarder riding pow at Winter Corner - December 28
The elevation at Winter Corner (high point  ~ 7000 feet) is relatively low, but it is tucked in a mostly northerly aspect that traps cold air and stays cold, preserving snow quality for weeks after a storm. In addition, several ridges around Winter Corner basin shelters it from wind events.
Early Morning Sun barely glazing a North aspect slope.
Not so unexpectedly, the snow cover and depth has greatly improved at Winter Corner as well as other areas at Mores Creek Summit that burn during the Pioneer Fire. Snow tree interception has been reduced or eliminated altogether at places. Reduced snow tree interception is permitting the development of a deeper snowpack that is covering deadfall, rocks, and brush much better than in the past. But we must also recognize the change in the forest canopy has other implications, such as the development of surface hoar and some types of surface facet due to radiation cooling. This will be an important winter to study and track MCS instability cycles and their linkage to landscape modification from the Pioneer Fire.
Winter Corner
The snowpack changed very little from our last visit to MCS on December 26th. An additional 15 cm of new snow now rests above 30 cm of the storm layer from December 24th. The Christmas day layer rest above a crust that is undergoing faceting.

At the places, we toured and skied yesterday we did not find the formation of a slab that will make the buried weak layer reactive, with few exceptions. We were searching and skiing pow lines. In other words, staying away from slabby snow.
Decorating Winter Corner with pow lines
There were some isolated steep spots where we observed cracking under our skis while building the uphill track. These isolated spots had 45 cms of soft snow resting on top of a well-developed facet layer.

The views of East Pilot Peak are splendid from Winter Corner. The next two pictures snapped from slightly different locations at Winter Corner allow us to appreciate the ski terrain East of Pilot Peak.
Pilot Peak - East aspect

Pilot Peak - East aspect
During "tea break" times, we observed as several folks skinned and skied Pilot Peak. We also heard the happy howling from a party descending the "Knob Ridge".

During the Christmas Holiday's Mores Creek Summit (MCS) has seen a healthy dose of visits from skiers and snowmobilers. Parking at MCS has been complicated due to limited plowing at the MCS snowmobile parking and pull-outs. To be safe when accessing your vehicle and avoid an Idaho City Sheriff Office ticket, skiers need to make sure they park their vehicles beyond the road edge. Since we all carry shovels let's make use of them. We are a caring community, and the parking space we shovel will be used by another party another day.
Creating a parking spot a pull-out. The space created for the vehicle has to be large enough to clear the road edge.
I wish that we were a community that will embrace a "parking fee" scheme, but it is unlikely. I am not aware of the reasons IDT is not regularly plowing the car pull-outs at I21/MCS pass area. But I suspect I will hear a litany about budget cuts.

As an American citizen, I have the right to access Public Federal Lands. And I am taking personal steps to exercise my right to tour and ride at Mores Creek Summit. I will continue to clear a safe spot to park my vehicle. A safe spot that will allow to safely unload and load the vehicle without affecting traffic at Idaho 21. I hope to motivate others to put some efforts and shovel parking spaces at I21 vehicle pull-outs. If we all put some effort into regularly shoveling snow at car pull-outs, it will get easier for all of us. We just need to take care of the most recent snow.

Tuesday, December 20, 2016

Mores Creek Summit Blog: New Goodies for 2017 Winter!

When you access the Mores Creek Summit blog at you might have notice the new look for this winter. But that was not the only change to the blog. The blog sidebar on the right has a collection of new goodies meant to help backcountry tourers with the information they require before heading out to ride the backcountry.

The sidebar has a selection for the temperature, the wind, air relative humidity, and solar radiation measured at the top of Pilot Peak (8142 feet).  The sidebar selection for Pilot Peak Summit data is shown in the screen capture included below. This information is useful during the planning an outing at MCS (Mores Creek Summit). Furthermore, is essential for tracking weather condition impacting the development of the snowpack.
The map selection on the sidebar has been updated with new maps for MCS. There are two versions, *.pdf and *.png. The maps have slope angles that help in visualizing where to place uphill tracks and where potential avalanche terrain might exist during periods of instability. Below the map for Pilot Peak East ridge.
REMEMBER, a topographical map will NEVER replace measuring angles with a phone slope app or a clinometer at the slope we intend to ride. Notice that the maps have elevation, contour lines, and distance are in meters.
These new maps show runs I like to ride with my family and friends at three general areas; East Freeman, West Freeman, and Pilot Peak. These maps are NOT meant to be a catalog of all the ski terrain at MCS!

In addition, a link for CalTopo maps is provided. The provided link will zoom into MCS and show slope angles as well as topographical information in feet. The original set of topo maps for MCS generated a few years ago are still there, at the bottom of the selection in the sidebar.

Another valuable goodie added to the sidebar are Weather resources for Pilot Peak and Boise Mountains. One of my favorites is the probabilistic interface to get the probability of snow for a period of 72 hours.
There is also a link for MesoWest, where weather stations in Idaho are displayed. I suggest configuring this site with an overlay of the southwestern Idaho weather radar, as shown below. There are other useful overlays, such as temp and winds, that allow us to gain insights about weather patterns.

The all familiar links for Southwestern Idaho Snotel Stations and nearby avalanche centers are also available in the sidebar.

We will continue to add new maps and tools to the blog during this winter, so keep visiting the blog.

Happy Holidays!

Saturday, December 17, 2016

A cold day at Freeman - December 17, 2016

Freeman air temperature was -16 ℃ and the snow surface temperature was -23 ℃. Yeap, it was cold. Fortunately, winds were light from the north. That made it easier to manage the cold conditions.
Freeman Peak East Ridge
Snow was creamy and dense at north and northeast aspects, but we found and rode nice POW at east aspects. East aspects were sheltered from Northwest winds that hammered Idaho Central Mountains when the cold front moved through a day ago.

There are a few Snotel sites that have anemometers, and one of those is Mores Creek Summit Snotel. Although, Snotel sites by design are located at wind sheltered locations. So when the Snotel sites register the wind, it means that the wind is blowing hard through the landscape. Check the wind event at Mores Creek Summit from December 15 through December 17. Notice from the chart that the wind was blowing from the west through northwest (200-320 Degrees).

Today there were four parties at Freeman Peak. Two of those parties were father and son. There was still a lot of brush at the bottom of drainages, but with careful selection, most brush could be avoided.
Father and 13-year-old son skinning-up
Freeman East Ridge - Photo by Jesse Dean
No evidence of instability was observed, with the exception of a steep rock spine with a small slab release. But it looked more like a localized terrain shallow slab release associated with the wind event. 

Before looking at the development of the snowpack we did a run on a low angle mid-elevation meadow. After quenching our thirst for pow turns, we were eager to get higher at Freeman Peak and search for a snowpit site.

Selecting a snowpit site requires that we weigh what type of information is the most relevant for the tour of the day. The tour planning reflected that we must evaluate the basal weak layer, as well the two near surface weak layer identified last December 8. Observation from early December at Mores Creek Summit suggests that basal weak layers developed primarily at slopes with some north aspects above 7000 feet. Furthermore, the tour plan required evaluating the impact of northerly winds on the skiing surface and avalanche stability. We needed to answer the following questions: Has the wind created wind slabs and loaded the snowpack? Were weak layers buried under the wind slab? The selected snowpit site attempted to address previous concerns with the snowpack and provide information about the recent meteorology events (wind and precipitation).

The snowpack at the snow-pit selected location had a depth of 115 cms and progressive hardness from Fist to 1-Finger at the bottom. The snowpit at confirmed that weak layers identified last Sunday, December's 11 have bonded to the snowpack.

The basal facets (depth hoar) were not reactive. As you might recall from a previous post, during Thursday-December 8, free water became available in the snowpack and it percolated to the basal layer. The basal layer now consists of a mix of facets bonded by a crust at Mores Creek Summit  (MCS) sites with elevations at or below 7500 feet.

Today we identified two new weak layers, one at 23 cm and the other at 30 cm from the snow surface. Both weak layers repeatedly produced easy compression failures (CTEQ1-SP). These two NEW weak layers did not show evidence of propagation propensity at all. Both weak layers consisted of precipitation crystals, and it is reasonable to expect that they will sinter and bond to the rest of the snowpack during the next few days, although the current cold temperatures will be slowing down the sintering and bonding process.

The top 10-15 cms of snow at MCS consist of a mix of precipitation particles and NSF crystals. We will have to pay close attention to this new weak layer undergoing advance facetting. Two storms are forecasted for Central Idaho Mountains for next week. It is likely that the new snow will be precipitating above this layer of Near-surface-facets (NSF). The current extended cold temperatures might result in a pretty widespread event, in which an NSF weak layer will be present at many aspects and elevations through are regional mountains.

A good skill to practice during the winter is to be able to light a fire in the snow. It works great to have a cigar lighter (regular lighters do not work well at elevation and cold temp) and wax impregnated toilet paper. During equipment breakdown or another unfortunate event, having this skill could change the experience from an uncomfortable to a very pleasant one! Cold days like today presented an opportunity to practice fire starting above snow surface skill. Thus, during our "Merienda" ( we enjoyed the comfort of a warm fire.
Photo by Jesse Dean

In a different note - I strongly recommend reading a report from Gallatin National Forest Avalanche Center about an avalanche accident last December 11. The avalanche accident report can be found at

The terrain where this heartbreaking fatality (father and son were involved) occurs reminds about similar places in Central Idaho mountains frequented by backcountry skiers. There are good insights into group dynamics. The next excerpt is revealing, to say the least:
With six ski tracks on the slope below, Delta and Echo had a frank discussion. Delta asked, “What do you want to do?” After discussing the potential wind pillow skiers’ right, Echo said, “Let’s burn a run and go back (to their previous slope).” In Delta’s words, “we forfeited digging a pit”. Below, there was lots of hooting and hollering in excitement from the great powder. Echo dropped in and the slope avalanched on his fourth turn. Delta yelled, “Avalanche” and kept his eyes on his Echo until he disappeared. 

Sunday, December 11, 2016

Summit Creek Glades - December 11, 2016

The best we can say about today is - It was a REALLY good Day. Nice cool tranquil weather, light winds, and fantastic soft snow conditions. Saturday denser snow surface was capped by 15-20 cms of low-density snow that made riding fast and FUN!
Grateful for having this wonderful resource so close to Boise.
Today felt like a yo-yo ski day. Instead of going for a grand tour we headed directly into the Summit Creek Glades. The two most popular glades were busy with other skiers. Besides, tracks from Saturday were still visible on those two ski runs as well. But Pilot Peak is full of great lines that are less obvious. Our plan was to ride on a pure north aspect, with steep wide corridors between trees.
Somewhere in Summit Creek Glades - Dead North slopes with steep pitches.
Saturday was relatively warm, with temps slightly above zero. The snowpack was loaded with an additional 87 mm of SWE (snow water equivalent). In effect, the snowpack more than doubled the total SWE for December 8, which was 76 mm. When a snowpack receives such a load in less than 48 hours, it should be expected the avalanche danger to augment. Multiple observers noticed on Saturday natural releases at steep slopes. Other folks experienced energetic whumpfs. When we arrived Sunday morning it was easy to find evidence of Saturday's instability cycle with a 24 hours old slab released across our parking spot. Overnight 15 to 20 cm of new light density snow was not sufficient to cover the instability cycle evidence.
Slab release at I-21, north of Mores Creek Summit. 
The coverage at Pilot Peak is improving rapidly, and today we were able to easily access backcountry terrain from parking pullouts and avoid using the Pilot Peak road. Elevations between 6000 and 7000 feet are now skiable with depths at the meter mark.
Skinning up Pilot Peak East Ridge -6400 feet of elevation
The forest fire at Summit Creek glades had minimal impact on the landscape. There are burnt trees, but the fire was spotty and it did not create new open areas for backcountry skiers with one exception, a glade below 7000 feet where the fire burn hot enough to leave match stick looking trees without limbs. To a great extent, the most visible impact is that the tree foliage is much reduced and visibility through the forest has greatly increased. It did not make sense that it seems that evergreen trees burn, but not  the ever-present brush. Weird!
Today's Playground - Summit Creek Glades
 As we skied in the glades, we noticed a number of slab release from the previous day on the same terrain and slope angles that we were skiing. The difference was that by Sunday the instability had decreased. The temps Saturday night and Sunday dropped to -6 Degrees C with light precipitation and calm winds. The liquid water resulting from above zero temperatures on Saturday had also percolated to the base of the snowpack and was retained in the basal facets (they were acting as a capillary barrier). And more importantly, the snowpack had adjusted to a large loading event.
Soft slab release at Summit Creek Glades
Quick pits are particularly important early in the season. It gives an insight into the development of the snowpack. Snow-pits are invaluable as they are repeated early the season since they allow us to identify changes the snowpack is experiencing in the most dynamic part of the winter.

The quick snow-pit we did, did not take time at all, and it told us as many things; water presence at the basal layer, 1-meter depth has been exceeded, the majority of the snowpack does not consist of facet crystals anymore, and layers are bonding. Quick pits are not only about stability testing, it is a LOT more important than that! It is about detecting the temporal changes the snowpack is going through! These observations improve your situation awareness. You are aware of what is happening under your boards.
Today's snow pit.
Snowpits are also valuable to test your snowpack development hypothesis. Your snowpack hypothesis is formulated earlier, perhaps during the planning of your outing. Our hypothesis was that the near surface weak layer identified last Monday had sintered, and the basal weak layer was still reactive. Very quickly we learned that indeed last Monday precipitation crystal weak layer had sintered and bonded, and that the basal layer was rendered ineffective by free water. Test results were unreactive at the basal layer.

We also gained new insights, from the snow-pit.  At a depth of 30-cm, a weak layer consisting of precipitation particles was responsible for moderate compression test results (CTM-Q2-Sudden Planar). This weak layer was also incapable of propagating a fracture at the location we inspected the snowpack because the slab lacked sufficient cohesion. The fracture propagation was arrested by a slab fracture. This information was key for selecting our terrain. We avoided areas where the snowpack is slabby, and rode on areas with cohesionless snow. EASY!

It is likely that the 30 cm instability will continue to decrease, the weak layer consisting of precipitation particles will bond to other layers rapidly, in contrast to persistent facet crystals that take longer to bond to other snowpack layers.

When the day was over, we skied out into the road along to the bottom of Summit Creek, and we were greeted by several snowpacks collapses (whumpfs) we triggered at the base of south aspect slopes. No surprise here, the snowpack topmost layer was dense and cohesive. A slab was present, and it was capable of sustaining propagation. It needed a steep slope to slide after the failure. But we were in low angle safe terrain.

Thursday, December 8, 2016

Dec 8-10 Storm - Let it SNOW!

Great news for this upcoming weekend. It is likely that by late Saturday we might have as much as 20 cms of new snow. Other forecast products predict as much as 50 cms.  Below a forecast product, I find helpful. It is hard not to notice the where the probabilities exceed 95% - right by Mores Creek Summit, Banner Summit, and Big Creek Summits. And these areas happen to be backcountry skiers playgrounds!

This NOAA forecast product is available at

Gosh, I can hardly contain my excitement ... Snow and snow and snow is coming to our mountains! I was getting tired of hearing about snow in other states and countries.

It has been a while since I shared informative maps of MCS. I think that today's posting is ideal. We can look at this maps of Pilot and Freeman Peak and daydream. And imagine where we would be skiing.

Pilot/Freeman Metric Topo
During the next few week, I will be generating final pdf files and be providing links for folks to download these maps of MCS.

Next - slope angle map. It is such an important part of ski touring and riding snow. Slope angles are responsible for BIG smiles.
Pilot and Freeman Peaks Slope Angle Map
It is important to realize that not all of the slope needs to be steep to slide. If a slope has an avalanche starting zone of 35-42 degrees, it is possible for the avalanche to be triggered and to continue moving at shallower angles.

For the map included above, areas in red have angles between 35-42 degrees, in orange between 28-35 degrees, in yellow 20-28 degrees, and green below 20 degrees. This map allows to easily identify uphill tracking routes to Pilot and Freeman Peaks. Once in the terrain, it is better to measure slope angles. And with today's phones and great slope angles apps, there are no absolutely no excuse not to know the slope angle before dropping in.

Other times we want to know where the snow stays cold and protected from solar radiation. A map with Northerly aspect is helpful.

Pilot and Freeman Peaks Northerly Aspects
Some other times we are interested in an estimate of how the snow is distributed in the landscape by winds during precipitation events. Few of us are working on that question at Boise State University. Below a preliminary output for an algorithm I had been playing with.

This algorithm attempts to graphically illustrate the areas where the snow accumulates or ablates. Blue color indicates where the snow accumulates. Red colors show where the snow is blown away by the wind. The output below assumes winds from the SW during the precipitation event.

During the next few weeks, I will be doing a depth measurements at Mores Creek Summit to test this model.

The Pioneer fire impact on MCS has been a usual topic of conversation. Next map showing the extent of the area burnt at Pilot Peak.

Changing gears - I have been to a number of professional avalanche educators workshops as well as snow science/avalanche conferences where it is discussed decision making in the context of groups. Unusual to me (I love to talk) I choose to remain silent. I believe most folks know how to make GOOD decisions. Of course, we make mistakes and that is not going to change. The key to consistent good decision making is having relevant information. And good information requires situational awareness.

Lately, I have seen a good intention focus about how to get folks going to the backcountry to make better decision in groups. I rather see more effort about how to make the group better inform and improve their situational awareness.  I have seen so many groups, many with avalanche education, being led by the most articulate, self-appointed leader, for all practical purposes nullifying group decision.

And life has provided too much evidence that of bad group decision making. Hence, I am skeptical of the power of a group thinking to make good decisions consistently. Especially when more often than not, there is a lot of misinformation and in particular a lack of situational awareness within the group. Politics provides many examples of this; Nazi Germany, Trump election, and the list go on. In theory,  well-informed groups should consistently make good decisions, but that is not the case in real life.

Map knowledge is one of the fundamental pillars to be well informed and develop situational awareness about the landscape in which we travel and ski. Maps are essential for planning. Perusing over maps in their various forms makes us experts in that area.

Similarly, reading about weather forecasts, reviewing forecasters discussions, and contemplating at weather maps is another pillar of situational awareness. Spending time analyzing weather forecasts familiarizes us with what the atmosphere will do (snow, winds, rain, temperatures, visibility, ...) and how the landscape, topography and WEATHER interact.

The message is that if we want to maximize our enjoyment while in the mountains and be safe we need to improve our situational awareness skills. And a great start is to be obsessed about having the best maps and sourcing the best weather forecast products of the areas we backcountry ride.  Not only we will be minimizing avalanche risks, but we will be maximizing the FUN factor by selecting locations to ride the most awesome pow!

Be safe out there this weekend. Remember we have several weak layers now buried deeper in the snowpack. Check the previous posting for details.

Monday, December 5, 2016

Pilot Peak - December 5

Finally, we received much-needed snow. The chart below shows the storm totals at Mores Creek Summit Snotel from last Sunday's storm. Take notice of the temperatures after the storm. Temperatures plunged into the negative teens. 

The good news is that snow coverage is rather uniform, even when comparing South to North aspects. Above 7000 feet the snow height is between 50 to 60 cm. The not-so-good news is that that the lower 1000 feet of elevation of Pilot Peak there are between 20-25 cm of snow, pretty much the latest storm snow.
Almost Top of The World
There was surface evidence of wind affected snow, but no wind loading at Pilot Peak backcountry skiing domain. The wind erosion marks in the snow suggested abnormal winds from the East to North East. The effect of the wind, and perhaps the storm rising temperatures by the end of the precipitation event resulted in mild inverted conditions. The skiing was still good, but boards with rocker will keep that tip floating and you will have a bigger smile when dealing with pockets of inverted snow conditions. So ... forget about the rock skis and bring your good boards.

The morning started rather chilly, in the negative teens, and it warmed very little during the day. The snow surface temps were cold. I usually suggest using high-quality infrared thermometers - there are a lot of crappy ones out there! IR Thermometers are compact and enable fast measurement of very relevant snow surface temperatures. It is also possible to make good snow surface measurements with a high response (low thermal mass) thermocouple thermometer and by using good technique. To avoid averaging temperature readings with air temperature care must be taken to cover the full probe under the snow surface top.
Thermocouple Thermometer measuring snow surface temps @ -18 Deg C.
Infrared Thermometer measuring snow surface temps @ -19 Deg C.
With these cold surface temperatures the new storm snow will metamorphose into facets in a few days, and the soft slab conditions will perhaps decrease during the next 48 hours, further improving the riding conditions.

The skiing was surprisingly good even with the relatively shallow cover (half a meter), mild inverted snow surface conditions, and unconsolidated snowpack. Although the danger of impacting buried rocks and treefall is very real, with careful observation and ski line selection it is possible to avoid damage to your boards and yourself.
Soft Slab skiing
Looking down - Almost Top of the World
Uphill track setting was uneventful, as long as you keep a healthy distance from trees, where the coverage was thinner, and rocks were close to the surface.
Skinning up 
Burn forest
We were surprised about the fire landscape. It looks like the fire did not burn too hot and it had a patchy nature. Most definitely it opened NEW tree lines that have not been skied before. Anyhow, it will take few more trips to fully assess the impact of the fire to Pilot's Peak Summit Creek drainage. And be ready to clean ash off your precious coats, dry snow works really good.

Keeping track of the snowpack is key early in the winter. Shallow snowpack and cold December conditions enhance the formation of basal weak layers. Colder permeable dry snow storms and cold conditions also favor the rapid formation of surface weak layers. Once these weak layers, basal or surface facets are loaded by more snow,  a slab develops above the weak layers resulting in persistent slab avalanche conditions. The persistent term refers to the case, where an avalanche instability lasts for a considerable amount of time.

The picture below shows today's snowpack with a depth of 57 cm. The picture also shows the fracture plane at 30 cm, 27 cms below the snow surface. There was a weak layer composed of 2-3 mm stellar precipitation crystals. We observed multiple soft slab easy sudden planar compression failures (CTEQ1-SP) as well as a whole block propagation failures. During compression testing, a single easy sudden collapse failure (CTEQ1-SC) was observed at a depth of 57 cm. 

These tests, as well as the snowpack development history, indicates that we should exercise caution in steep terrain. The snowpack is shallow and it is faceting fast. Indeed it is losing its slab properties. But once it gets loaded by new snow, the basal weak layer might become active. We just need loading event (snow precipitation) and a cohesive structure (wind or warms temps) to support fracture propagation on the EXISTING weak layers. 

Under more temperate conditions (temps closer to 0 Deg C) the weak layer buried 25 cms below the snow surface will metamorphose within 48 hours due to rounding and sintering. However, the present cold temperatures are going to slow down rounding/sintering metamorphism.

Below a chart with the temperature profile of today's snowpit. The differences between IR and TC sensors are a subject of research I am doing and it has to do with IR emissivity of various crystals structures as well as differences between bulk and surface temperature measurement. More on that subject in a future posting.

Take a look at the temperatures at the 30 cm layer; -7 Deg C for IR thermometer and -4 Deg C for thermocouple thermometer. These temperatures contrast dramatically with the very cold surface temperatures. Also, above the 30 cm depth, the gradient augments (bigger change in temperatures per unit of depth).  At depths above 30 cm, the steeper gradients will result in much higher water sublimation rates that will drive strong faceting. This facet metamorphism will improve skiing conditions and reduce the slab cohesiveness of the top layers.

The snowpit chart with relevant information such as aspect, elevation, time, weather, temperature and hardness profiles, etcetera is included below. Inspection of this chart should easily portrait where the weak points - or weak layers are located below the snow surface.

These profiles are easy to produce using online tools from  By using this non-commercial tool, you will be  helping snow scientist with your snow field data. 

Next Thursday there is another chance for another snow precipitation event. The snow forecast is for light to moderate amounts, in the order of 10 cms. We should be vigilant, the new snow will be burying at least two reactive weak layers. This weekend, take the time to identify these two layers. Remember to make conservative decisions, it is early in the season, and we need time to dial our backcountry travel techniques and situational awareness skills.

After two years abroad in Europe doing snow research, I am back to Idaho. It is good to be able again to ski through the full winter in Central Idaho mountains. I hope you enjoy the new format, colors, as well as my renewed enthusiasm to share snow conditions from our playground.