How Aspen’s troubles in getting slopes open aligns with climatic trends — The Mountain Town News

From The Mountain Town News (Allen Best):

Ski slopes in Colorado and other parts of the West were slow to turn white this now-departed winter. That’s not terribly unusual. For nearly all of the modern resort era, ski hill bosses have periodically summoned Native Americans to speak to the higher powers. Ski areas can announce opening dates months in advance, but weather keeps its own schedule.

Snowmaking can overcome that varied natural schedule. But even snowmaking failed the Aspen Skiing Co. and many other ski areas in Colorado and elsewhere early in the past season. It was just too warm.

Snowmaking begins at temperatures of 26 degrees F. or less, but the machines can really crank at temperatures of 10 degrees Fahrenheit, observes Victor Gerdin, mountain planner for the Aspen Skiing Co.

“Not only did we have very few days of 26 degrees or less, we had practically no days of 10 degrees in November and December,” he told the Aspen Daily News.

Aspen plans to plow $5.5 million into new snowmaking equipment before next winter at its four ski areas. Some of the new equipment will replace older, less energy-efficient infrastructure. But Aspen also hopes to expand terrain covered by snowmaking, especially so at its money mountain, Snowmass.

Can snowmaking overcome the effect of global warming altogether? No—and some ski areas too low in elevation to sustain cold temperatures are almost certain to fall by the wayside. But for others, snowmaking can provide a crucial margin to sustain operations. The key, says Robin Smith, a snowmaking consultant, is that resorts invest in the most modern equipment, to maximize opportunities during shrinking windows of cold temperatures.

Robin Smith. Photo credit: Allen Best

Smith, who has several dozen clients among ski areas across the country, says some of his customers have lost 30 percent or more of their snowmaking windows in the last decade. “That makes snowmaking tougher,” he tells Mountain Town News.

He foresees significant challenges for lower-elevation ski areas on the East Coast, the Midwest and elsewhere. Aspen, Vail and other higher elevation resorts in the Rockies will still have snow, but will face problems —similar to this year—of increased weather volatility produced by the warming atmosphere.

In a 2016 study, the Environmental Protection Agency projected temperatures in decades ahead for 247 ski areas in the United States. The study concluded that warming temperatures will cut deeply into the 450 hours of sufficiently cold temperatures that ski areas commonly believe they need to make snow in time for Christmas openings. That study, however, did not address the potential savior of automated snowmaking systems, says Smith, of Snowconsult.

This past winter was a challenge for many ski areas in Colorado, California and other regions. The National Oceanic and Atmospheric Administration released a map for December through February showing that much of western Colorado, including Aspen, had “much above average” temperatures.

This fits with what Aaron Smith, a ski patroller at Aspen Highlands, told Auden Schendler, Aspen’s vice president for sustainability, during the early season struggles.

“He said that it wasn’t that there was no snow coming down. It was that when any (solar) radiation hit it, it melted right away,” says Schendler. “That speaks to warmer temperatures I think.”

This fits in with the conclusions of a paper published in February 2017 by Water Resources Research. The authors of the paper declared that the drought of the 21st century in the Colorado River Basin actually had more to do with temperature increases than precipitation declines.

One of the researchers, Brad Udall, of Colorado State University’s Colorado Water Institute, laid out the thesis at a conference in downtown Denver recently. He said that a 20 percent decline in overall precipitation has been recorded in the basin from 2000 through 2017. This is despite a 5 percent increase in moisture content in the warming atmosphere.

“Something very odd and unusual is going on,” Udall said at the inaugural Water in the West Symposium.

“Something very odd and unusual is going on,” Udall said at the inaugural Water in the West Symposium.

Udall’s partner in the research, Jonathan Overpeck, formerly of the University of Arizona and now dean of the School of Environment and Sustainability at the University of Michigan, further fleshed out the study a few days later at the 2018 Next Generation Water Summit in Santa Fe.

The two big reservoirs on the river, Powell and Mead, were full in 1999, he pointed out. Powell was 52 percent full and Mead 39 percent fill as of April 28. Lake Mead, with a surface level now at 1,080 feet, is likely to drop below 1,075 feet, the place where shortage criteria kick in.

A canal delivers water to Phoenix. Photo credit: Allen Best

“That’s why we’re now starting to see fights over water again,” he said, alluding to a flurry of sharply-worded letters from upper-basin states to the Central Arizona Project. The upper-basin states accuse the Arizona agency of manipulating water demands and supplies for self-gain, at the expense of other water users.

Why are the reservoirs emptying? It’s not drought, as conventionally understood. It’s what Overpeck and Udall call aridification.

“Precipitation in this current drought is a contributor, a secondary contributor. The main cause of this drought is temperature,” said Overpeck.

The warming atmosphere, he explained, demands more moisture. This is accomplished in various ways. Most significant is increased evapotranspiration from soil and plants Precipitation is also sublimated from snow, there is more rain and less snowpack, and the growing season is longer. Plus, of course, there is more evaporation from surface water.

“Stop thinking about drought as precipitation,” he said.

Modeling indicates that if we tamp down emissions that temperatures will rise only 1 to 1.5 degrees C (2.7 to 3.6 degrees F), he said. But at the top end, without changes, warming of 5 to 7 degrees C (9 to 12 degrees F) can be expected.

Might the warming atmosphere produce more precipitation? Overpeck concedes that possibility. Climate models that cover Colorado have suggested a trend toward less precipitation in the Southwest and more precipitation in the northern half of the state. But water experts have warned that the models at this relatively micro-level have great ranges of uncertainty.

But even more precipitation falling from the sky will not result in precipitation that lingers on the ground, said Overpeck.

The Rio Grande Basin may be even harder hit. The river starts in the San Juan Mountains of Colorado, flowing past Taos and Santa Fe. U.S. Senator Tom Udall (a cousin to Brad Udall), speaking at the same conference, suggested more reservoirs are needed in the headwaters of the Rio Grande instead of at Elephant Butte, the big down-stream reservoir that loses so much water to evaporation.

In Denver, Brad Udall said temperature-induced losses in the Colorado River Basin will triple by 2050 and increase almost six-fold by the end of the century.

Earlier this year, Oregon’s Philip Mote and other researchers also fingered rising temperatures in a study of changing hydrology.

This won’t end skiing in the high Rockies, but it does suggest that the warm temperatures that frustrated efforts by Aspen and many other ski areas from making snow last November and December will become more frequent in decades ahead.

Nearly the full length of Lake Powell on the Colorado River in southern Utah and northern Arizona is visible in this photograph shot by an astronaut aboard the International Space Station, on Sept. 6, 2016. The view is toward the southwest. Water flow is from the lower right toward the top. (Source: NASA Earth Observatory)

Some ski areas will have it worse than others. The EPA study concluded that given the current trajectory for greenhouse gas emissions, most skiing—even with snowmaking—will be gone in the East, Midwest and coastal Far West by 2090. Some of ski areas will be closed even sooner, within 30 years.

Smith, writing in the May issue of Ski Area Management, said he “absolutely believes the temperature predictions” produced for individual ski areas by the EPA study. However, the EPA study failed to account for improvements in snowmaking as well as the durability and resistance to melting of machine-made snowpack, he says.

Can snowmaking compensate? If the United States and other countries contain greenhouse gas emissions in line with the targets identified in the Paris climate accords, the answer seems to be yes, at least until 2050, and for most all resorts well beyond.

“But that’s only if each resort can adopt today’s cutting-edge snowmaking technology on a significant enough percentage of its terrain,” wrote Smith, who previously worked for five years as the North American representative for Italian snowmaking manufacturer TechnoAlpino.

“Automated snowmaking systems will be essential, because the windows of snowmaking opportunity will get smaller, and the available hours will become less. This has been happening already, of course. My clients in the last 10 years have observed 30 percent fewer total snowmaking hours under 28 degrees wet bulb. For clients with full automation, the diminished hours have not shortened their season at all.”

That’s if the world constrains emissions. If not? What if we continue with business as usual?

“Things get more difficult for all areas outside of the Central Rockies and the High Sierras, especially after 2050. We’d need some kind of technological breakthrough I don’t see coming.”

About Allen Best
Allen Best is a Colorado-based journalist. He publishes a subscription-based e-zine called Mountain Town News, portions of which are published on the website of the same name, and also writes for a variety of newspapers and magazines.
View all posts by Allen Best →

New Signs of Trouble Ahead for #ColoradoRiver Basin Water Managers — Allen Best #COriver

Morning on the upper Colorado River. Photo: Brent Gardner-Smith/Aspen Journalism

From RouteFifty.comn (Allen Best):

Peak runoff in the Colorado River this year has arrived exceptionally early and with unusual modesty. It’s part of a pattern in the 21st century, one that scientists warn will become even more common in the future.

One measuring site is at Cameo, located amid sandstone cliffs coated with desert varnish two hours downstream from Aspen and Vail and a short distance from Grand Junction. There, runoff in the Colorado River reached 6,650 cubic feet per second on Monday. Unless surpassed by a second surge of runoff predicted for Saturday, it is likely to be the earliest date for peak runoff at the site in 50 years, according to the Colorado River Water Conservation District.

It’s also a runoff of modest flows, the fourth lowest in 85 years of record-keeping at Cameo. The lowest was in 1977, according to the Glenwood Springs-based River District, followed by those of 2002 and 2012—and now 2018.

Winter was warmer and drier than usual, and the last month has been the same: 2 to 4 degrees Fahrenheit warmer than average. Spring precipitation has similarly lagged across western Colorado…

Taking the long view, [Jeff] Lukas notes there’s a lot of “noise” or natural variability in the climate records. But this clustering suggests a changed norm. What used to be the sort of runoff that might occur every 25 years could now, perhaps, be expected about every 10 years.

The latest “E-Waternews” is hot off the presses from @NorthernWater

Horsetooth Reservoir looking west from Soldier Dam. Photo credit: Norther Water.

Click here to read the newsletter. Here’s an excerpt:

Northern Water works with partners to prevent spread of nuisance species

Area resource managers will be tightening requirements for launching motorboats, sailboats and personal motorized watercraft at Horsetooth Reservoir and Carter Lake boat ramps in the weeks to come. Both reservoirs are part of the Colorado-Big Thompson Project.

New requirements from the Eastern Colorado Area Office, Bureau of Reclamation, will mean that boat ramps will remain locked except when an inspector is present. People staying in backcountry boat-in campsites and visitors wanting to fish after 10 p.m. should be aware of this change, because boat ramps will be closed from 10 p.m. to 6 a.m. These protective measures are intended to prevent illegal launching without inspection, which could result in introduction and infestation of the reservoirs by invasive aquatic species such as the quagga and zebra mussels.

Boaters should be aware of ramp hours to ensure access to the ramp at the end of their visit. A full schedule is available here.

Northern Water is providing in-kind resources and funding to ensure the success of the program.

To see the full news release, click here.

Climate Change Is Making Droughts Worse In The Western U.S. — @KUNC

From KUNC (Luke Runyon):

A new study from NASA reinforces the idea that droughts are getting worse and could become more frequent in the Western U.S.

The culprit is human-caused climate change.

Droughts aren’t just about precipitation, says NASA scientist and the study’s co-author Benjamin Cook. They’re also about the timing of snowmelt and the wetness of soil, both of which are upended by a warming climate…

“We have pretty clear evidence now that climate change has already begun to make droughts worse or more likely in at least some regions,” he says. “So it’s a now problem, not a future problem.”

Definitions of drought vary. A meteorological drought happens when snow and rain are diminished. An agricultural drought is tied to soil moisture and can be influenced by the type of soil and the crops and vegetation grown. A hydrological drought refers to lessened runoff from snow, which in turn means less water ending up in surface reservoirs.

Here’s the link to my post about the late Kelly Redmond’s commentary, “The Depiction of #Drought,” required reading from professor Fleck.

Nowadays you have to include the “hot drought” and “aridification” in your calculus. Read this publication from the Colorado River Research Group, “When is drought not a drought? Drought, aridification, and the “new normal.”

The latest #ENSO discussion is hot off the presses from the Climate Prediction Center

Click here to read the discussion:

ENSO Alert System Status: Final La Niña Advisory

Synopsis: ENSO-neutral is favored through September-November 2018, with the possibility of El Niño nearing 50% by Northern Hemisphere winter 2018-19.

During April 2018, the tropical Pacific returned to ENSO-neutral, as indicated by mostly near- to- below average sea surface temperatures (SSTs) along the equator. The latest weekly Niño indices were near zero in all regions (between +0.2°C and -0.3°C), except for Niño-1+2, which remained negative (-0.6°C). Subsurface temperature anomalies (averaged across 180°-100°W) remained positive, due to the continued influence of a downwelling oceanic Kelvin wave. Atmospheric indictors related to La Niña also continued to fade. While convection remained suppressed near and east of the Date Line, rainfall near Indonesia was also below average during the month. Low-level winds were near average over most of the tropical Pacific Ocean, and upper-level winds were anomalous westerly over the eastern Pacific. Overall, the ocean and atmosphere system reflected a return to ENSO-neutral.

The majority of models in the IRI/CPC plume predict ENSO-neutral to continue at least through the Northern Hemisphere summer 2018 (Fig. 6). As the fall and winter approaches, many models indicate an increasing chance for El Niño. Therefore, the forecaster consensus hedges in the direction of El Niño as the winter approaches, but given the considerable uncertainty in ENSO forecasts made at this time of year, the probabilities for El Niño are below 50%. In summary, ENSO-neutral is favored through September-November 2018, with the possibility of El Niño nearing 50% by Northern Hemisphere winter 2018-19 (click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

As warming continues, ‘hot #drought’ becomes the norm, not an exception — #NewMexico Political Report #aridification

West Drought Monitor May 15, 2018.

From the New Mexico Political Report (Laura Paskus):

“Climate change for the Southwest is all about water,” said Jonathan Overpeck, who has spent decades studying climate change and its impacts in the southwestern United States. Warming affects the amount of water flowing in streams, and the amount of water available to nourish forests, agricultural fields and orchards. There’s also the physics of the matter: A warmer atmosphere holds more moisture, demanding more from land surfaces. Plants need more water, too. “Any way you look at it,” Overpeck said, “water that normally would flow in the river or be in the soil ends up instead in the atmosphere.”

[…]

Past southwestern droughts were notable for declines in precipitation. But today’s droughts are different, he explained. Even in wet years, which will still occur as the climate changes, warmer conditions dry out the landscapes.

“With atmospheric warming, we’re getting what we’re calling ‘hot droughts’ or ‘hotter droughts,’” he said. “That means that they’re more and more influenced by these warm temperatures, and the warm temperatures tend to make the droughts more severe because they pull the moisture out of plants, they pull the moisture out of rivers and out of soil—and that moisture ends up in the atmosphere instead of where we normally like to have it.”

From 1952 until 1956, below-normal rainfall caused “critical water deficiencies in much of the southern half of the Nation,” according to a 1965 U.S. Department of the Interior report. The 1950s drought had widespread impacts on New Mexico’s communities and economy. Today’s drought conditions, which Overpeck explains have been moving around the Southwest for 19 years, are exacerbated by warmer temperatures. The global temperature is 1.8 degrees Fahrenheit higher than it was in 1880, and the Southwest is warming at an even faster rate.

“What we’re seeing now in the drought that’s going on is that it’s more due to temperature increase and less due to precipitation deficit,” he said. And “hot drought” is what we should prepare to face in the future, too.

“More and more so, the droughts will really be defined by hotness, by warm temperatures that just suck the moisture out of the soil, suck the moisture out of our rivers,” he said. “And leaves the droughts an ever more devastating manifestation.”