Thursday, April 25, 2024
Big Ups for Atmospheric Sciences at the U
Sunday, April 21, 2024
We've Created a Monster
Last Week, the Kem C. Gardner Policy Institute at the University of Utah released a detailed fact sheet highlighting the economic contributions of Utah's ski industry. If it seems like the Utah ski industry has changed dramatically in recent years, this study largely confirms it. A few interesting tidbits.
Skier days have really taken off since 2020/21 with each year since setting a new record, reaching 7.1 million in 2022/23. And that 7.1 million was reached with Little Cottonwood being closed by avalanche hazard for the latter part of the season. If it seems like there are more people at the resorts than there used to be that's because there are.
Where did all these skiers come from? During the 2022/23 season, 44% were from Utah. The rest came from all over the place. Want to blame California? They are the biggest non-Utah source, although they represent only 8% of skiers. Colorado is good for 2%. I think they come for the snow.
One graph examined the relationship between annual snowfall (apparently at Alta) and skier days. I look at this chart and I see the variability caused by seasonal variations in snow being somewhat small through about 2017/18 when growth takes off and dominates.
There was no attempt to look at backcountry skiing. Although the number of skier days is probably a factor of 10 or more smaller, I suspect the growth rate is even larger than the skier days at ski resorts.You can access more at https://d36oiwf74r1rap.cloudfront.net/wp-content/uploads/2024/04/SkiIndustry-FS-April-2024.pdf
Friday, April 19, 2024
Just Past Peak Upper Elevation Snowpack
The statewide snowpack water equivalent, based on an average of all stations in Utah, peaked on April 1-2 at 18.8 inches and after fluctuating just below that value for about 10 days, has been steadily declining and now sits at 15 inches.
Source: NRCS |
The peak of 18.8 inches was 117.5% of the median peak of 16 inches, so it's been a decent snow year statewide.
The situation though varies depending on region and elevation. We'll focus here on the Wasatch Range. The lowest elevation SNOTEL site in the Wasatch is Ben Lomond Trail in the North Ogden Valley, which is at 5971 ft. The snowpack at Ben Lomond Trail also peaked on April 1–2. This is a snowy location, so the peak snowpack water equivalent was 28.4", more than 10" higher than the state average, despite the low elevation.
After April 8, the snowmelt at this site began in earnest and it has since shed a bit more than 10" of water, or a bit over a third of the snowpack.
Above this site at the Ben Lomond Peak SNOTEL site, which is at 7688 ft, the snowpack peaked at 53.4" where it sat at from April 8–11. It has declined only slightly since.
Source: NRCS |
Source: NRCS |
Given that forecasts look pretty dry for at least the next few days and mild to warm, I suspect it is safe to say that we are well past peak snowpack now in the mid elevations, are probably past peak on upper elevation south aspects, and are likely past peak on upper elevation north aspects.
Tuesday, April 16, 2024
The Fate of Alpine Glaciers
In the previous post, Climate Change Case Study: Austria, we examined recent trends in snow measures and potential impacts of future warming on skiing in the eastern Alps. Declines in snow and snowcover are evident in the recent past and expected to continue in the next few decades in low- and mid-elevation areas. High-elevation resorts in Tyrol, where resorts more commonly extend above 2000 meters, are the most "climate resilient" but will still feel the effects of climate change. Ski area viability declines with ongoing greenhouse gas emissions and future warming. One estimate suggest that with 2°C of warming relative to 1961–1990, only 64% of Austrian ski areas will be snow reliable. With 4°C of warming, this number drops to 16%.
In this post we look at the fate of glaciers in the Alps. Glaciers are large masses of land-based, perennial ice, and they exist at upper-elevations throughout the Alps. The map below shows the Alpine glacier coverage circa 2010. Small glaciers are found from the far western to far eastern Alps, with the greatest concentration of large (5–100 square km) glaciers in the highest Alpine terrain from roughly Mt. Blanc to Zermatt (between about 6.75°E and 8°E).
Source: Huss (2012) |
Large glaciers exist elsewhere in the Alps, however, including the Swiss Jungfrau (southeast of Bern), where the Aletsch Glacier glacier, the largest and longest in the Alps is found, the Ă–tztal and Stubai Alps of Austria's Tyrol, the Ortler and Rhaetian Alps of Italy southwest of Bolzano, and the Hohe Tauern in eastern Austria (between 12°E and 13°E).
Monte Rosa and the Gorner Glacier above Zermatt |
Glaciers in the Alps have been losing mass and retreating in recent decades. This reflects what is happening across the globe. The graph below shows the cumulative mass change in mass balance for reference (i.e., well-monitored over decades) glaciers (in cumulative meters of water equivalent) illustrating the downward trend. Central Europe (blue) includes trends from Austrian (6), Swiss (5), French (3), Italian (2), and Spanish (1, Pyrenees) glaciers.
Source: Zekollari et al. (2019), with annotations added. |
Source: Zekollari et al. (2019), with annotations added. |
Last week, the Austrian Alpine Club released it's annual glacier survey and report. They have been surveying glaciers in Austria for over 100 years, but this one got a lot of coverage because they warned that Austria will be largely ice free in 45 years. In other words, perennial ice will largely be gone. This is generally consistent with my scientific understanding, although I hope that perhaps some high-altitude glacier remnants may survive in the Austrian Alps if we can get our act together.
Wednesday, April 10, 2024
Climate Change Case Study: Austria
It was a great ski season here in northern Utah, but the situation at low elevations in the Alps this year was dismal. The photo below was taken on March 3rd at Brixen im Thale, part of the SkiWelt Wilderkaiser – Brixental megaresort in the eastern Tyrol of Austria. Despite it being early March, the natural snowpack was non-existent and artificial snow was scant.
This is a low elevation area. The photo is taken at 800 meters and much of the skiing in this region is is below 2000 meters. At these elevations, snow is especially vulnerable to temperature, and this winter was remarkably warm in the Austrian Alps. Geosphere Austria, the state meteorological and geophysical science service, reported that February was the warmest on record, with a mean temperature in mountainous areas an incredible 5.9°C (10.6°F) above the 1961–1990 average. The impacts can be seen above. This was followed by a March that rated as the warmest in history in the Austrian lowlands and the ninth warmest in the mountains. Basically, this winter was a disaster for lower-elevation skiing.
On the other hand, March snow depths at upper elevations of the western Austria states of Vorarlberg and Tyrol were 10 to 20 percent above average, whereas in the central Austrian States they were near average. Basically, it was a tale of two altitudes. That said, does this represent the future of skiing in the Austrian Alps? Let's take a look.
Recent Trends
Austria has an extensive snowpack observing system. For the 2nd edition of Secrets of the Greatest Snow on Earth, Marc Olefs of Geosphere provided me with long-term trends of seasonal mean snow depth (top figure below) and snow cover duration (bottom figure below) in Austria from 1961–2021. No observing sites in Austria show positive trends in either of these variables. Roughly 67% exhibit statistically significant declines in average snow depth and 80% show statistically significant declines in snow-cover duration (i.e., the length of time with at least 1 cm of snow on the ground). These trends tend to be largest at lower elevations.
Source: Steenburgh (2023). Data from Olefs et al. 2021 and updated through 2021. |
Note that with one exception, these sites are below 2000 meters. In western Austria, there are resorts that go to well above that elevation, including a few places where lifts extend to more than 3000 meters, such as Stubai Glacier, Hintertux Glacier, and Sölden. These resorts have upper-elevation glacier skiing and typically long seasons. Hintertux Glacier is currently the only ski area in the world with year-round operations (Zermatt attempts to do this, but has not been able to the past two years due to poor glacier conditions).
It is well documented that glaciers in the Alps are loosing remarkable amounts of mass. One of the most studied glaciers in the world is the Hintereisferner in the Ötztal Alps about 15 to 20 km from Sölden as the crow flies. The annual mass balance of the Hintereisferner has been negative every year since 1983 and losses have been accelerating.
Source: https://wgms.ch/products_ref_glaciers/hintereisferner-alps/ |
There are no "good" years for glaciers in the Alps anymore. Oh, you might hear that they had a good winter (this winter might have been a decent one at upper elevations), but the insidious influence of temperature is simply too overwhelming. Hintertux Glacier goes to extreme lengths to enable summer skiing operations, which I suspect are not going to continue much longer.
Source: Steenburgh (2023), from 80-20/Shuterstock.com |
Future Snowfall Trends
Source: Frei et al. (2018) |
Source: Steiger and Abegg (2011) |
Source: Steiger and Abegg |
Summary
Tuesday, April 9, 2024
It's Over
I'm calling it. Spring is here. Powder skiing chances now will be increasing intermittent.
The final powder weekend was a good one. It was ideal for April powder skiing with a goldilocks dump that covered much of the buried crusts, a remarkably cold airmass, and enough cloud cover to limit the caustic effects of the now high-angle sun.
Forecasts for this week are not hopeful if you are hoping powder. Below is the 7-day GFS. Mt. Baldy (11,000 ft) tempeatures rising the next few days into the 30s. Near 50 at Alta Collins. Maybe a shower or two, but not enough to enable real powder skiing.