NAS FIELD SESSIONS OFFER FOUR DAYS OF INTENSIVE SNOW STUDY
STORY AND PHOTOS BY CANDACE HORGAN
It’s late in the afternoon, and as the sun dips lower in the orange-hued sky and passes behind a ridge to the west, eight of us are gathered around a pit we have just dug in the snow at Arapahoe Basin Ski Area in Colorado. The pit is approximately 35 centimeters by 150 centimeters, and has been dug into a snowpack that is about 135 centimeters deep. One of our instructors, Karen Bockel, dips her snow crystal card into a layer, taps the side of it, and starts passing it around with her powerful loupe.
“Take a look,” she states. “What do we think? Rounding facets? Rounds? See the bonds between the crystals and how they look strong?”
So it goes on day one of the Pro Level 1 — NAS field sessions for the National Avalanche School at Arapahoe Basin. This is just the first of four intensive days of avalanche study that includes companion rescue testing, snowpit and snow crystal analysis, snow-water equivalent (SWE) and weather station measurements, morning and afternoon avalanche forecasting, and more.
“I really am appreciating digging pits and looking at the different crystals,” said Dave Childs, a patroller with Thunderbolt Backcountry Ski Patrol in Massachusetts. “You know, back East our crystals are kind of a mess. Here, it’s a little better to find a lot more variety to look at.”
The field sessions were run by the American Avalanche Institute, which teaches both recreational and professional-level avalanche courses. The session at A-Basin was led by Sarah Carpenter, one of AAI’s co-owners, together with Bockel and Andy Lapkass, the program director for the National Avalanche School. Arapahoe Basin Snow Safety Director Ryan Evanczyk also taught all four days, and Evanczyk had assistance from A-Basin patrollers Michelle Gmitro, Kyle Hagadorn, and Keith Hiller at various points during the week. Denny Hogan was there to audit the class for the American Avalanche Association.
This year marked the first in the partnership between the National Avalanche Foundation and the American Avalanche Institute to put on the field sessions for the National Avalanche School. AAI ran four sessions this winter, one at Jackson Hole, Wyoming; one at Breckenridge, Colorado; one at Park City, Utah; and one at A-Basin.
“In the last couple of years I’ve talked to Janet Kellam and Andy (Lapkass) quite a bit about the National Avalanche School, and with the pro-rec split going on, it ended up that eventually, Janet proposed, hey what if NAF (National Avalanche Foundation) keeps running the classroom sessions, and AAI with its resources comes in and runs the field session,” states Carpenter. “It was a partnership that was proposed by the National Avalanche Foundation, and knowing the folks that were involved, and knowing the folks teaching the classroom session, obviously we were excited.”
All four sessions sold out. With over 100 people taking the biennial classroom sessions of the NAS, it is likely that AAI’s field sessions in winter 2019 will also be packed, something that Carpenter is clearly thrilled with.
“It’s been great to be welcomed in the ski areas to work with their snow safety professionals and work out of their particular areas. I think so far it’s been a great partnership. I think with what the National Avalanche Foundation and their whole crew of instructors brings to the classroom session, and we at AAI have known and worked with most of those folks for so long, the continuity is there in terms of messaging, and the resources that we all rely on are quite similar, and I think so far it’s been a great partnership, and we’re really excited to continue to move it forward and grow it.”
People who complete both the classroom and field portions of the NAS earn a Pro Level 1 — NAS certification. This certification differs slightly from the standard Pro Level 1, a difference that will be greatly appreciated by ski area management.
“The difference is that Pro Level 1 — NAS has a really specific ski area focus,” says Carpenter. “On a regular Pro Level 1, we talk about ski areas, we talk about record-keeping, we talk about how things fit in if you’re in a guiding operation versus area, but the National Avalanche School Pro 1, that’s purely our target audience, the people involved in ski areas, so some of the presentations are tweaked. Following routes is something that we obviously don’t do on a regular Pro 1, so it’s definitely more focused on that target audience. And then the other difference is there’s four days of classroom instruction in the fall and then four days of field instruction, so you’ve got eight days of instruction in the National Avalanche School Pro 1 versus five days of instruction on the regular Pro 1.”
Though the focus of the NAS field sessions was snow study in the field, together with companion rescue and weather forecasting, there were indoor presentations too. On Monday, Evanczyk introduced the group to the three A-Basin weather stations and how they can be used in their morning forecast. The stations can be called up on a computer and show temperatures, winds, snow accumulation, and more. Evanczyk also discussed the challenges the Continental snowpack presents with the formation of persistent weak layers and depth hoar.
Carpenter followed by refreshing the group on the different types of snow metamorphism and how that affects crystal shapes and what those crystal shapes mean to the strength or weakness of the snowpack. Bockel ended Monday’s indoor sessions with a refresher on snowpits and what data should be collected at each pit, including depth, aspect, layer boundaries and hardness, grain types for each layer, temperature at relative depths in the snowpack, and stability tests like the Compression Test and Extended Column Test.
After the indoor session, the group got a full tour of the main A-Basin weather station and its various instruments from Evanczyk. The station is located near the mid-mountain lodge.
Most of the afternoon, however, was spent on either a companion rescue test or digging a snowpit and taking measurements. With a large class of 17, the group split into two to make this more manageable. The companion rescue test is a timed beacon test. A single rescuer must find and daylight two buried packs in a 50 meter by 50 meter search area. Each pack was buried approximately a meter down. Most of the group passed this test on the first try; those that did not got some instruction and then retook the test on the last day.
Tuesday got into more of the challenges with managing terrain at a ski area. The morning started with smaller groups discussing their homework from the previous day, a morning forecast of the avalanche hazard level, the avalanche problem type, and the overall weather picture from the previous 24 hours. It ended with a presentation on an avalanche path at A-Basin and showed how to calculate things like the vertical fall of the path, potential run-out zones, and the alpha angle for potential 100-year slides.
The participants then broke into groups of three to head into the field. One group was led by Bockel, one by Carpenter, and one by Evanczyk. Each visited that slide path and took actual measurements, including overall slope angle and slope angle in different parts of the slope. The rest of the day was spent on snowpits and stability tests. Carpenter’s group went into an undisturbed area within Arapahoe Basin’s SUP (Special Use Permit) just outside a gate to dig their first pits and found a touchy, shallow snowpack. Most of the pits, dug in low-angle terrain, yielded test results of ECTP with the propagation happening in the 18-25 zone. (An ECT starts with 10 taps from the wrist, then 10 from the elbow, then 10 from the shoulder. For instance, a test that fails on the eighth tap from the elbow and propagates would be recorded as ETCP 18.)
After digging snowpits in this area, the group went back inside the ski area and dug pits first in terrain above treeline and then below treeline, finding interesting data in all areas.
At the end of the day, the group reconvened to discuss how to do an afternoon avalanche forecast. This forecast is something that can be used by the next day’s staff as part of their overall avalanche mitigation plan and strategy. The homework assignment was to again do a morning avalanche forecast.
Wednesday’s indoor session got into the nittygritty of mitigation inside a ski area. Mitigation strategies take input from weather observations, the evolving snowpack structure, and the avalanche forecast, and then consider various N S ways to mitigate the hazard, including boot packing, side-stepping, ski cuts, using a compaction roller, and the use of explosives and an Avalauncher. The goal with mitigation is to disrupt potential weak layers and the overall natural avalanche cycle.
Everyone then headed out on the hill and got to see A-Basin’s main Avalauncher. Evanczyk explained how the Basin’s patrollers use it to shoot various places on the East Wall and how in early season also use an Avalancher in Montezuma Bowl.
From there, the groups again split. Gmitro took one group out toward the new Steep Gullies terrain and showed them the new Explosive Delivery System, which allows the Basin’s patrollers to safely deliver charges with a fixed cable and a trolley to shoot the steep terrain in that area. Gmitro also gave a demonstration of how the Basin’s patrollers would run hand routes in other areas accessed from the Pallavicini chairlift, which serves much of the Basin’s expert terrain. This demonstration was greatly appreciated by some of the participants.
“I love the driven toward operational experience, especially how A-Basin runs all their operations,” said Kyle Armstrong, who has patrolled at nearby Breckenridge Resort for four years. “It’s a little bit different than Breckenridge, but I’m still taking in a lot about routes and shot placements, and I’m really interested in the bomb trams (Explosive Delivery System).”
Other groups hiked up to the top of the East Wall and checked out the hand routes the Basin’s patrollers do there. After that, everyone gathered in an area near the Shooting Gallery Avalauncher at the base of the East Wall and dug pits in preparation for the final snowpit test on Thursday. The instructors all circulated to help the students with crystal identification, stability tests, and identifying the hardness of the various layers.
The homework assignment for Wednesday night was to prepare both a morning and afternoon forecast to turn in the next day. These were collected Thursday morning, along with the students’ fieldbooks, as part of the final grade. As the class learned, documentation is extremely important.
“I need to work more on my documentation,” said Chuck Boyd, the NSP Eastern Division Avalanche Program supervisor of what he learned. “I have a lot of field experience, but I know I really don’t document as much as it seems that’s being required now. So it’s pretty interesting. I’m learning a lot. I have a lot of takeaways to bring back to my classes. We are going to teach a Level 2 this year, so some of the things that we’ve done in the classroom here are going to be little classroom assignments in our Level 2 class.”
Thursday was supposed to bring a lot of snow and increased hazard for the class to forecast, but the snowstorm was delayed and didn’t really hit till the next day. The area got a sprinkling of new snow, which made for great skiing as the class skied the Spine on Palli and descended the Christmas Trees area to the site of the final exam.
For that portion, the students first had an hour to dig a pit, take the appropriate temperature measurements, identify the layers in the snowpack, identify the crystal type of each layer, and then do a Compression Test and Extended Column Test. The students had to document all their observations in their fieldbooks and show the fieldbooks to the instructors. The instructors also observed all the stability tests to make sure the students were conducting the tests appropriately.
The next part of the final exam was a test on conducting weather and snowpack observations. The class had to document the overall snowpack depth at a snow stake, document the height of the new snow, the boot depth in the new snow, the temperature of the snow at the surface and 20 centimeters down, and also calculate the SWE of the new snow using a Snowmetrics device.
“I’m really hoping to get one of those,” said Shannon Maguire of the SWE equipment. Macguire has patrolled at Sierra-at-Tahoe for 10 years and took the NAS classroom session in 2013. She also appreciated the snowpack observations. “The Continental snowpack is so different than our typical maritime climate, but as we’re in these drought years, drought cycles, we’re seeing more faceted weak layers that don’t disappear as quickly as usual because we’re having such a shallow snowpack. So I think that’s going to be helpful as we proceed in potential drought years.”
To finish up their experience, the students gathered into six different groups indoors and played avalanche forecaster on Teton Pass in Wyoming. First, each group was Skinning up for a trip back to the area. Making snowpit observations. Winter Park patroller Austin Foote during the NAS field sessions. Arapahoe Basin patroller Michelle Gmitro shows off the Basin’s Explosive Delivery System. Making snowpit observations. 6 4 NSP.ORG AVA L A N C H E given snowpit and snowfall data from November through early January, and then a storm cycle came in that dumped three inches of SWE in a short period of time. The groups had to decide when to close the pass, when to shoot the various avalanche paths, and how to clean up debris. Every group buried the highway multiple times during the scenario, which had Carpenter giving two-hour snowfall data and wind updates and asking each group to make decisions. This exercise was based on a real incident that closed Teton Pass for almost two days.
Everyone who attended the class felt the experience was invaluable.
“I feel like it’s well organized, a lot of valuable information,” said Maguire, “I feel like it’s a good synthesis of stuff that I do at work, stuff I have practiced with. I’m used to doing it, but it’s a very organized way of pulling it out, tying it all together, and refreshing the skills you don’t always use.”
The class also gave Boyd and Childs, both NSP Avalanche instructors in the East, an opportunity to dial in skills better and learn instructional tactics.
“(Not only) learning about avalanches themselves, but how the instruction process works is really important,” said Childs. “Seeing what they emphasize, what they don’t emphasize, their timelines, and the way they run some of the programs is really helpful for us as instructors.”
“I think it’s a lot of value for Eastern patrollers to travel,” said Boyd. “It’s a big thing I’m pushing in NSP. We have trouble having enough snowpack to do a Level 2, so unless we have five or six feet of snow to dig in, I can’t hold our Level 2 classes back East. I have one scheduled for this year, and if that doesn’t materialize then starting next year we are going to take the Eastern Division Level 2 Avalanche class on a trip, and we are going to do it out West, either in the Rocky Mountain Division or the Intermountain Division. We’ve been invited by both divisions to share courses with them.”
It wasn’t only learning from the instructors that the students felt was important; they also learned a lot from talking to each other about their resorts’ avalanche problems and mitigation strategies.
“I think it’s really interesting to get other people’s perspectives and other operational perspectives and just come together,” said Armstrong. “I’ve never seen a snow compacter, so that was really interesting, and then also to see how Winter Park does it and talk to those guys.”
As the partnership between NAF and AAI continues going forward, it will prove a tremendous learning opportunity for patrol directors and mountain management as they look to add to their snow safety staff. The National Avalanche School is one of the best opportunities for patrollers to learn snow science and then learn about how they can apply this knowledge in their everyday work routines.
“It’s been a high-caliber group of students,” said Carpenter. “What we’ve noticed is students coming into the Pro 1 — NAS field sessions have quite a bit of experience. We’ve had people with eight, 10, 12 years of patrolling experience in this NAS Pro 1, versus our other Pro 1’s we’ve had a few folks with that experience, but the majority are less experienced. The caliber of students and the outcomes from these courses have been notable; they’ve been impressive.” +