POW Alliance members McKenzie Skiles & Jared Shumate Study Snow Trends and the Viability of Future Olympic Games in Salt Lake City
It is no secret that declining snow cover and increased variability between seasons are impacting outdoor winter sporting events. At the start of the 2022/23 season, seven of the first eight International Ski Federation (FIS) Alpine World Cup events were canceled due to “warm temperatures, bad conditions, and lack of snow.” Every discipline of skiing and snowboarding has seen events canceled for these same reasons, both nationally and internationally.
The venues most threatened by climate change are those at lower elevations. As the climate warms, precipitation at lower elevations is increasingly falling as rain rather than snow during winter months. This has the most direct and immediate effect on cross country skiing venues that are required to take place at lower elevations: the International Ski Federation (FIS) and the International Biathlon Union (IBU) limit the maximum elevation of courses to 1,800 meters (5,900 feet) above sea level. Some venues have consistently been forced to cancel events due to unfavorable conditions, while other venues seem to be safe (for now) from the effects of climate change on winter sporting events.
Our Motivation
As climate change continues to impact venues around the world, the International Olympic Committee (IOC) has recognized that the number of suitable sites to host the Winter Olympics is dwindling. One suggested solution has been to pick a permanent set of ‘climate-reliable’ rotating hosts. In the near term, however, the next two selections are expected to be the French Alps (2030) and then a return to Salt Lake City, UT (2034) which have been recognized as preferred hosts for the upcoming Winter Olympic and Paralympic Games.
As two Protect Our Winters Alliance members based in Salt Lake City, Dr. McKenzie Skiles of the Science Alliance and Jared Shumate of the Ski Alliance (and 2022 Olympian), we were interested in looking at how consistent snow cover has been since the Winter Olympic and Paralympic games were last held in Salt Lake in 2002. The outdoor venues then included Deer Valley Resort, Park City Mountain Resort, Snowbasin Resort, the Utah Olympic Park, and Soldier Hollow Nordic Center. The last two of which were built so that Salt Lake City would be a suitable Winter Olympic host. Seeing if, and how, snow cover is changing at these sites could indicate what to expect in 2034, and the viability of Salt Lake City as a permanent rotating host.
What we did
To assess trends in snow cover across venues we used satellite-based snow cover data. The NASA instrument MODIS has been collecting daily images of the earth since late 2000, and from the imagery, the extent of snow cover can be mapped. We used a metric known as the fractional snow covered area, which quantifies the snow covered portion of each image pixel (500 m2). We report this as a percentage, where 50% indicates half of the pixel is snow covered. This is the best approach to determining snow covered area and duration from relatively coarse imagery in variable mountain terrain. For reference, we show a map visualizing the snow data over Salt Lake City below. Although the imagery is relatively coarse, being able to quantify snow cover almost daily is ideal because mountain snow cover, especially at lower elevations, can change quickly. While we are still digging into this data we wanted to share some of the most relevant early outcomes of this study with the POW community.
We analyzed the snow covered area patterns as monthly averages between January 1 – March 31 of each year over the satellite record (2001 – 2023), as historically, the Olympic and Paralympic games are held within that time frame. We focused our analysis on a “neighborhood” of pixels encompassing each of the five venues. An example of one of these neighborhoods is shown in the map below. Due to other land surface types, like tree canopies and built infrastructure (roads, buildings) within these areas, maximum snow cover is typically 80 – 90% across the venues.
What We Found
We have good news and bad news about snow cover patterns at the 2002 Olympic outdoor venues around Salt Lake City. The good news is that the higher elevation resort venues, all with base areas above 6,300 ft, have had relatively high and consistent snow cover since the last Winter Olympics. The average winter snow cover at Deer Valley, Park City, and Snowbasin was approximately 85% across all three sites with relatively low variability (6% – 8% standard deviation). The Utah Olympic Park, also at a higher elevation, had snow covered area values similar to the resort venues in higher snow covered winters. The venue was more impacted by low snow cover years, though, and had a slightly lower average snow cover (78%) and more variability (16% standard deviation) relative to the resort venues.
The bad news is that Soldier Hollow Nordic Center, at 5,800 ft, has had consistently lower (average 61%) and more variable (29% standard deviation) winter snow covered area relative to the other sites. All venues experienced periodic below average snow years over the satellite record, but the magnitude of those bad snow years was especially notable at Soldier Hollow. For example, 2015 was a historically low snow year and below average snow covered area occurred across all venues in February and March. Soldier Hollow, though, was the only site with no detectable snow cover during the whole month of March in 2015. Across the whole record, it was also the only site to experience periodic low to no snow cover conditions across each of the winter months, and the only site to have multiple years with no detectable snow cover. Unfortunately, given the trend in shorter seasons, declining snow coverage at lower elevations, and cancellation of events, this was not totally unexpected.
Observation based studies, including those by Dr. Skiles, are documenting faster snowmelt and an earlier end to winter in mountain regions around the globe. Seasonally, these impacts are visible in the snow covered area across Utah’s outdoor venues. Varying degrees of lower and more variable snow cover happen across sites in the month of March, with the impacts being most dramatic at the Olympic Park and Soldier Hollow. The average snow cover at Park City, for example, drops from 87% in February to 81% in March. Whereas at Soldier Hollow, average snow cover declines by nearly half from February (71%) to March (37%).
Looking more closely at what contributes to the dramatic decline in average snow cover from February to March at Soldier Hollow shows that in nearly half of the years included in our dataset (11 out of 23), Soldier Hollow had lower than 25% snow cover in March. When we add in snow depth to the analysis, in more than half of the years (15 out of 23) Soldier Hollow had less than 3” of natural snow on the ground in March. This is particularly relevant for snow consistency during the Paralympics, which have traditionally been held in March, following the Olympics in February.
It is important to note that the snow covered area data cannot distinguish between natural and man made snow. Included here is a photo of Jared competing at Soldier Hollow on a day with 43% snow cover. With all of the bare ground in the image, most of that 43% snow cover is man made snow. This could be skewing some of our results, indicating higher snow cover than would have been there naturally. This also, however, raises another related and relevant topic: as climate warms, the ability to make and retain snow and ice also becomes less reliable. This has relevance for outdoor venues like the Utah Olympic Park that rely less on natural snow and more on highly managed snow and ice for sliding and jumping events.
Although we only analyzed what has happened with snow cover in the twenty or so years since the last Olympics, our study indicates that future snow cover may be a concern for the 2034 Olympic and Paralympics in Salt Lake City despite Utah having “The Greatest Snow On Earth”. None of the outdoor venues in Utah are immune from climate change and the warmer weather and inconsistent snow cover that comes with it. The 2002 Winter Olympics had extensive snow cover through March, but as variability between years increases it is difficult to say which, if any, future years will hold consistent snow through the entire winter season. It may even be worthwhile for the IOC to consider shifting the timing of the Olympic and Paralympic Games to earlier, as we found snow cover to be most consistent in January and February.
Lower elevation sites, such as Soldier Hollow, show the most dramatic effects of climate change now. This indicates that it may be time for FIS and IBU to consider hosting cross country, nordic, and biathlon events at higher elevation venues. It’s not only low elevation venues at risk, though. As the climate continues to warm the duration and coverage of snow will continue to decline over time and become less reliable year-to-year. Given this, it is important to consider climate change as a threat to even the highest elevation sites, demonstrated by the cancellation of the FIS Alpine Ski World Cup in Zermatt-Cortina due to warm temperatures despite a startline higher than 12,000 ft (source). With 10 years until the proposed 2034 Salt Lake Olympics and Paralympics, it is hard to say which of Utah’s outdoor Olympic venues will still be “safe”.
Author: McKenzie Skiles & Jared Shumate
McKenzie Skiles first became interested in snow and climate change growing up in Anchorage, Alaska, and found that pursuing snow hydrology was the perfect way to combine her love of snow and mountains with her interest in earth science and climate change. She is an Assistant Professor in the Geography Department at the University of […]
