2019 Colorado Snow and Avalanche Workshop
The Colorado 2018-2019 winter season will be a season to remember with heart-wrenching incidents, widespread community impacts, and visible scars on Colorado’s mountain landscape. Looking for more insights, a wide range of professionals and recreational users flocked to the River Walk Center in Breckenridge for the 18th Colorado Snow And Avalanche Workshop, hosted by the Colorado Avalanche Information Center.
The workshop’s agenda, bookended by opening and closing remarks from Ethan Greene, CAIC director, reflected the significance of this past season with perspectives ranging from retrospectives on the March 2019 avalanche cycle to data collection and research on avalanche recreation and tools used in decision making as well as the efficacy and reliability of forecasts from avalanche bulletins to snowfall to climate outlooks.
Brian Lazar, CAIC deputy director, provided a summary of the season from October to February and zoomed in on the March Cycle as a significant avalanche cycle that involved moisture-heavy slabs across all aspects and a strong Colorado snowpack.
A dramatic increase in the Snow Water Equivalent (SWE) combined with significant accumulations measured in feet served as the beginnings of what could arguably be the most destructive state-wide avalanche cycle ever recorded in Colorado’s modern history.
Art Mears, the engineer behind the now well-known splitting wedge in Conundrum Creek, followed up on Lazar’s summary with a perspective of D3 to D5 avalanches in regards to release, flow, and destructive potential during the March cycle. In his analysis, a strong cohesion between the storm slab and the snowpack seemed to facilitate large fracture propagations that ripped down to the midlayers and below.
These slides also resulted in a deeper salination flow which stripped trees of their branches very high off the ground. Mears pointed out how significant it was to see the amount of debris that was brought all the way to the end of these runouts, a testimony to the amount of destructive energy in these large avalanches.
Drew Peterson, field manager for the Colorado Office of Emergency Management, provided a perspective from a first responder/community management point of view in terms of immediate and long-term impacts. Peterson highlighted the long-term impacts in terms of stress and trauma on communities affected as well as the high number of organizations and agencies involved in coordinated communication and responses at a local and regional level. The San Juans fared better than expected in regards to flooding thanks to a marginal monsoon season.
Kelly Elder, a researcher with the US Forest Service, described the ongoing efforts to document avalanches from the perspectives of tree dendrochronology, or study of annual growth rings, as part of the Colorado Big Avalanche Project. Data collection involves cutting tree trunk discs as well as drawing core samples from living trees and describing tree characteristics. Elder has his work cut out for him with over 1000 samples to analyze!
Anne St. Clair, a public avalanche forecaster for Avalanche Canada, presented on study results out of Simon Fraser University’s Avalanche Research program from the point of view of avalanche education and decision making. Building on the work of Phase 1 with individual interviews on decision-making processes, Phase 2 consisted of a survey targeted towards backcountry recreation users and professionals on their avalanche awareness and use of avalanche bulletin tools.
With a significant sample size of over 3,000 respondents, the survey allowed St. Claire to parse through the type of avalanche bulletin users, as well as identify a critical issue for Canada: their design of the compass rose seemed to be more difficult to use as a tool compared to the compass version used in the United States. This revelation goes in hand with the overall goal of resource differentiation and usability design for different audiences.
Frank Techel, an avalanche forecaster with the WSL Institute for Snow and Avalanche Research SLF, provided some data-driven perspectives of verifying regional avalanche forecasts as well as the challenges forecasters face in maintaining accuracy across different regions. Compared to other regional forecast offices, CAIC ranks high in terms of accuracy.
Techel also showed how bias towards danger ratings very across regional forecast offices, and highlighted how CAIC’s forecasts may be more biased towards higher danger ratings. This bias could be also interpreted as a tendency not to lower danger rates as quickly as others, given the wide variability across regions within Colorado.
Laura McGladrey, a NOLS instructor/advisor and nurse practitioner, brought a different perspective to CSAW in regards to mountain-based first responders and stress management. She reminded us to consider not only the victim(s) but also the bystander or witness who may be dealing with a different type of injury caused by stress. First responders also have a responsibility for self-care and stress management, and McGladrey showed us the impacts of different states of mental health on individuals from the perspectives of passion, work ethics, and mission readiness.
Answering the question “why are the models wrong?” Trevor Alcott of NOAA System Research Laboratory explained the principles behind operational weather models and the ensemble approach to forecasts on different scales from global to local. Alcott also described some of the limitations in using these different tools, especially when it comes to forecasting snowfall.
Kris Sanders, a forecaster with the National Weather Service office in Grand Junction, continued the theme of weather with an overview of last year’s climate outlook versus actual results and described the challenges in making long-range forecasts. Given the alphabet soup of different global mechanisms for energy transfer, it’s understandable that we all take these climate outlooks with a grain of salt.
From an infrastructure point of view, Jaime Yount, Winter Operations Program Manager for CDOT, gave an overview of progress made in Colorado for remote avalanche mitigation. He also described the benefits, maintenance, and costs for the different kinds of remote controlled avalanche systems (RACS) from Gasex to O’Bellx to Wysson towers as well as considerations and priorities for keeping highways open during avalanche cycles.
Focusing on low frequencies not audible to humans, Jeffrey Johnson and co-auther Hans Peter Marshall of Boise State University developed an array of microphones to document infrared sound created by avalanches for the purpose of understanding avalanche dynamics better. Little Cottonwood Canyon in Utah served as a controlled test site for natural avalanches without the presence of acoustics from explosives.
Unfortunately, my developing sinus cold forced me to leave before I could hear from Jeff Deems on digital mapping tools and Frank Techel on Level 5 Avalanche Danger in the Swiss Alps.
Friends of CAIC leveled up in their efforts to reach a wider audience by providing live video access through Facebook for those who couldn’t attend in person.
Overall, the workshop’s agenda felt relevant to the conversations taking place in the community regarding decision-making, avalanche bulletin usage, group dynamics, as well as the big picture of living with avalanche danger in Colorado.
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