Facing a drier future, water managers turn to science — The Rio Blanco Herald-Times #ColoradoRiver #COriver #aridification

A flight from NASA’s Airborne Snow Observatory gathers data about the snowpack above the reservoir on a June 24 flight. Information gathered from the flight helped Denver Water manage reservoir operations. Photo courtesy of Quantum Spatial

From the Colorado River District via The Rio Blanco Herald-Times:

A growing body of research shows that the Upper Colorado River Basin is growing warmer on average. In fact, the national hot spot centers on Western Colorado and much of the Southwest.

A result: a significant reduction in the snowpack that makes up the Southwest’s main water supply.

In the Colorado River District’s “Know Your Snow” webinar, Deputy Chief Engineer Dave Kanzer and National Snow and Ice Data Center researcher Jeff Deems explored how water managers and snow scientists are studying and adapting to the changes to our snowpack and water supply.

The “Know Your Snow” webinar is available online at http://www.coloradoriverdistrict.org/events-directory/webinars/ (scan the Zapcode on the photo to the right with your Zappar smartphone app for a direct link.)

About three-quarters of the snowmelt that forms the Colorado River’s flow falls as snow at elevations above 8,500 feet in the mountains of the Upper Colorado Basin, Kanzer explained. Deems pointed out that the 15 Western Slope counties that make up the Colorado River District have warmed at a rate from about 2 degrees Fahrenheit in Summit County to more than 4 degrees in Mesa, Montrose, Ouray and Rio Blanco counties since about the early 1900s, according to data developed by the National Oceanic and Atmospheric Administration.

“We’re seeing changes on the order of 4 or 5 degrees in parts of the District,” Deems said. “This is just a slice out of this big, warming bullseye that is hitting the Upper Colorado (River) Basin over that time period. This is a problem for us because we rely on the snowpack, and that’s because warming reduces stream flow through a number of different mechanisms in this snowmelt-dominated basin.”

That reduction comes from several factors: more snow falling as rain, earlier spring snowmelt, more snow directly evaporating into the atmosphere instead of melting into streams and a longer growing season that has plants taking up more water.

Deems explained that for every 1 degree of warming, there is an estimated 3 to 4% decline in annual runoff. That’s about double the amount of water Las Vegas uses in one year, and 18 months of water supply for the city of Los Angeles, Deems said.

A recent study by the U.S. Geological Survey found that a decline in flow due to warming is even greater than earlier studies have shown, with statistics suggesting that average annual flow decreases by 9.3% for every 1.8 degrees of warming.

All of this poses a threat to drinking water, irrigation to grow our food and water to maintain healthy wildlife habitats. The Colorado River District is not only studying the water-supply risks posed by warming temperatures but also implementing solutions such as cloud seeding to make sure West Slope communities are prepared for future challenges.

Cloud-seeding graphic via Science Matters

Cloud seeding to increase snowpack

As part of an effort to boost snowpack, Kanzer coordinates the Colorado River District’s cloud seeding program. Increasingly, water managers are turning to cloud seeding, a practice that can increase how much snow winter storms produce.

“We’re trying to figure out how to mitigate and adapt to a changing world,” Kanzer said. “We’re doing this through cloud seeding, and (we’re) implementing these programs throughout Western Colorado. In fact, this is going on throughout the West and throughout the world.”

Cloud seeding requires a specific set of conditions to be successful, Kanzer explained. A cloud must contain super-cooled water. Water vapor in these clouds is cold enough to form ice crystals, around 5 to 23 degrees Fahrenheit, but it needs something on which to crystalize. When conditions in a storm system are right, with favorable winds with proper uplift, cloud seeding generators send tiny particles of silver iodide into the moisture-laden clouds, typically using propane-fired burners on the ground.

Silver iodide has been proven to be safe for the environment, Kanzer said, adding that it is effective because and it naturally has a similar crystal structure to the ice crystals that form snowflakes.

The super-cooled liquid water more efficiently freezes on to these introduced tiny particles of silver iodide, building small ice crystals that grow into snowflakes.

Kanzer said cloud seeding could increase snow on the ground by up to 15%, boosting what might have been a 10-inch snowstorm by 1.5 inches. After a successful season of cloud seeding, this might, in turn, lead to as much as a 5% increase in streamflow in watersheds where cloud seeding occurred. This increases recreation opportunities for skiers in the winter and boaters in the warmer months, he added.

“And it helps us with our water supplies, of course, and that’s what we’re really focused on here at the Colorado River District,” Kanzer said.

This map shows the snowpack depth of the Maroon Bells in spring 2019. The map was created with information from NASA’s Airborne Snow Observatory, which will help water managers make more accurate streamflow predictions. Jeffrey Deems/ASO, National Snow and Ice Data Center

Improving predictions with better data

While Kanzer’s work focuses on increasing the amount of snowpack, Deems’ research seeks to better understand what snow we have.

He explained that water supply forecasts are traditionally generated by comparing the current amount of snow on the ground at fixed locations to historical streamflow records. With the changes we are experiencing, Deems said these methods of comparing the present to the past are no longer accurate.

Additionally, snowpack is measured by a network of weather stations widely spread out across the mountain landscape where Colorado’s snowfall accumulates. While these stations provide accurate measurements in very specific locations, they don’t indicate how much snow, and how much water, might be stored high in the mountains, above the elevations where these stations are located.

Deems’ company, the Airborne Snow Observatory, uses a system called light detection and ranging — LIDAR for short — to measure snow across the entire landscape. From a plane, Deems’ team sends pulses of scanning laser light toward the earth, which reflect off the snow. Researchers can then use information in the reflection to build a three-dimensional picture of the snowscape.

This technology gives snow scientists and water planners landscape-based information about how much snow, and water, is present. This technology is detailed enough to reveal the deep pockets of snow below bare slopes where avalanches occurred or even areas where snowmaking was used to make terrain parks on a ski run.

This more comprehensive of the snowpack significantly improves water supply forecasts critical to water managers in making decisions.

Together with cloud seeding, this technology is helping water managers turn the corner from historical practices to prepare for and adapt to a changing world in the Upper Colorado River Basin.

For more information, visit ColoradoRiverDistrict.org. The “Know Your Snow” webinar is available online at http://www.coloradoriverdistrict.org/events-directory/webinars/.

Cloud seeding study validates ski industry staple — @AspenJournalism

Scenes from the Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) project, which was undertaken in Idaho’s Payette Basin in winter 2017. Credit: Joshua Aikins via Aspen Journalism

From Aspen Journalism (David O. Williams):

n innovative new study conducted in Idaho and published on Monday seems to confirm what Vail and other Colorado ski resorts have believed for decades — that “cloud seeding can boost snowfall across a wide area if the atmospheric conditions are favorable.”

“This is a revelation. We can definitely say that cloud seeding enhances snowfall under the right conditions,” said Sarah Tessendorf, a scientist at the National Center for Atmospheric Research in Boulder and co-author of a new paper on the research conducted by scientists from the University of Colorado Boulder and University of Wyoming, among others.

Cloud seeding uses ground-based generators to disperse dust-sized silver iodide particles into clouds so that ice crystals can form on those particles and fall to the ground in the form of snow. Scientists, water managers and ski industry executives say it’s precipitation that would otherwise stay in the clouds, so cloud seeding is an environmentally safe way to enhance snowfall.

But the efficiency of cloud seeding has so far been hard to prove. Tessendorf said previous cloud seeding studies were unable to achieve statistically significant results because the natural variability of the weather was too great and demanded a larger sample size than could be reasonably obtained, for financial reasons.

In winter 2017, the National Science Foundation, which sponsors NCAR, teamed up with the Idaho Power Company to conduct a field study called SNOWIE (Seeded and Natural Orographic Wintertime Clouds — the Idaho Experiment).

SNOWIE used supercomputing technology to develop a new computer model to simulate cloud seeding, as well as new measurement capabilities, such as a high-resolution cloud radar on a Wyoming research aircraft that can see previously invisible cloud features. Researchers also located mobile radars on mountain ridges north of Boise to see clouds not visible to stationary National Weather Service radars that are blocked by the mountains themselves.

The scientists then used airborne seeding instead of ground-based generators because the silver iodide dispersed downwind from the aircraft in a zig-zag pattern, which is a very unnatural pattern for precipitation to form.

That allowed the scientists “to unambiguously detect the impact of cloud seeding in these clouds using the mobile and airborne radars,” Tessendorf said. “This had never been done before. In the three cases we report on, there was negligible natural snow falling, so the zig-zag pattern was able to be detected very clearly and tracked to the ground to quantify the snow reaching the ground due to seeding.”

One of the examples cited in a press release accompanying the study was a cloud-seeding flight on Jan. 19, 2017, that generated snow for 67 minutes, dusting about 900 square miles with a tenth of a millimeter of snow beyond what was falling naturally.

“This was barely enough snow to cling to the researchers’ eyelashes,” the release reads, ‘but it would have stayed in the air if not for cloud seeding.”

“We tracked the seeding plume from the time we put it into the cloud until it generated snow that actually fell onto the ground,” said Katja Friedrich, a University of Colorado Boulder professor and lead author of the new study.

Scenes from the Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) project, which was undertaken in Idaho’s Payette Basin in winter 2017. Credit: Joshua Aikins via Aspen Journalism

Finding the ideal storms

Dave Kanzer, deputy chief engineer for the Colorado River District, helps oversee a system of 25 ground-based cloud-seeding generators in the central Colorado region that includes Grand, Summit, Eagle and parts of Pitkin County. Nearby generators include one atop Arrowhead and another above Camp Hale.

Kanzer said storms from the north and northwest, which tend to be colder, are ideal for cloud seeding, with temperatures in the clouds no higher than 21 degrees Fahrenheit and no lower than 5 degrees Fahrenheit. If the clouds have the right temperature range and the right moisture levels but lack sufficient particles for ice crystals to form, that’s where cloud seeding comes in.

“We take advantage of the first two and we add the proper amount of particulate matter to enhance the snowfall and precipitation … and that accumulates in the snowpack somewhere in the range of between 5 and 15% on a per storm basis when those conditions are met,” Kanzer said. “And that helps to increase the water yield of the snow sheds in the range of 1 to, 4% of water on a seasonal basis.”

Scenes from the Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) project, which was undertaken in Idaho’s Payette Basin in winter 2017. Credit: Joshua Aikins via Aspen Journalism

A tool to maintain snowpack

The Colorado Department of Natural Resources regulates cloud seeding, permitting operations in nine different parts of the state. The operations in the central zone, at the headwaters of the Colorado River, are funded by a wide range of groups, including Front Range utilities and water districts that divert Western Slope water, including Denver Water and Northern Water.

The Colorado River District spends around a $150,000 a year contracting with Western Weather Group to run the program, which Kanzer said is about the same amount Vail Resorts spends on the program for its four Colorado ski areas – Vail, Beaver Creek, Breckenridge and Keystone.

Vail Resorts declined to comment for this story.

Kanzer presented on cloud seeding at a November Eagle River Watershed Council meeting in Avon, where a few of the 50 or so participants got heated in their questioning of the environmental safety of the process.

Kanzer said cloud seeding is safe, using inert silver iodide that cannot be detected in the environment after it’s released into clouds. He added the process could become increasingly critical to maintaining mountain snowpack as the climate changes.

“It’s one tool that we can use to mitigate or adapt to the changes that we have not only predicted but are starting to experience with shorter snow-covered seasons,” Kanzer said. “And so (cloud seeding) helps us extend that time or at least forestall the reduction.”

Aspen Journalism collaborates with The Vail Daily and other Swift Communications newspapers on coverage of water and rivers. This story ran in the Feb. 25 edition of The Vail Daily.

Cloud-seeding graphic via Science Matters

Scientists demonstrate that #cloudseeding can generate snowfall — @NCAR_Science #snowpack #runoff

Here’s the release from NCAR/UCAR (David Hokansky):

Scientists announced today that they have successfully used a combination of radars and snow gauges to measure the impact of cloud seeding on snowfall. The new research addresses decades of speculation about the effectiveness of artificial methods to increase precipitation, demonstrating unambiguously that cloud seeding can boost snowfall across a wide area if the atmospheric conditions are favorable.

“This is a revelation,” said Sarah Tessendorf, a scientist at the National Center for Atmospheric Research (NCAR) and co-author of a new paper about the research. “We can definitely say that cloud seeding enhances snowfall under the right conditions.”

The researchers, including scientists from the University of Colorado Boulder, University of Wyoming, and University of Illinois at Urbana-Champaign, arrived at their results by analyzing detailed observations taken in a cloud seeding experiment in Idaho during the winter of 2017. They found that injecting clouds with silver iodide generated precipitation at multiple sites at the ground, sometimes creating snowfall where none had existed.

The study provides the most comprehensive evidence to date that cloud seeding can generate rain or snow.

Tessendorf cautioned, however, that successfully producing precipitation requires the presence of clouds. The results are also dependent on such atmospheric factors as local winds. Even when cloud seeding enhances precipitation, there are additional factors that will determine if it is a cost-effective approach to increasing snowpack or replenishing reservoirs.

“The seeding produces ice and that ice can form snow, but is it enough additional snow to make it cost effective?” she asked. “For water managers, the bottom line is the amount of snowpack that you’re building over the whole winter and how much runoff it will generate. We are looking into some promising approaches to address those bigger questions, but we still have plenty of work to do to get there.”

The study was published this week in Proceedings of the National Academy of Sciences. Funding came from the National Science Foundation (NSF), which is NCAR’s sponsor, and from the Idaho Power Company.

A scientific challenge

As far back as the 1940s, scientists demonstrated that injecting certain types of particles into clouds could induce ice to form and grow around them until they fell out of the clouds.

But measuring what effect, if any, cloud seeding had on measurable rain or snow proved very difficult. Researchers compared the amount of precipitation from randomly seeded clouds with similar clouds that were not seeded, but such statistical analysis produced mixed results, partly because natural precipitation is so variable that it is difficult to pick out the signal from the noise. Other work has indicated that cloud seeding can boost precipitation at specific locations, but left open the question of whether the increase in precipitation extended across significant areas.

To tackle the question, NSF and the Idaho Power Company launched a major field project in the winter of 2017 called SNOWIE (Seeded and Natural Orographic Wintertime clouds — the Idaho Experiment). Researchers used airborne and ground-based radars, high-resolution snow gauges, and computer modeling to quantify the impact of injecting silver iodide into clouds over the Payette Basin region north of Boise. The seeding aircraft released silver iodide along a flight path that resulted in a zigzag pattern of seeding effects in the clouds.

Scientists used the Doppler on Wheels radar to measure snowfall in the Idaho mountains that was generated by cloud seeding during the SNOWIE field project. Photo by Joshua Aikins via NCAR

This approach enabled the research team to observe the entire process and compare the side-by-side seeded and unseeded areas.

“We tracked the seeding plume from the time we put it into the cloud until it generated snow that actually fell onto the ground,” said Katja Friedrich, a professor at the University of Colorado Boulder and lead author of the new study.

The results show that, on at least three occasions, the seeding measurably boosted the snowfall across the targeted watershed. A cloud seeding flight on January 19, 2017, for example, generated snow for about 67 minutes, dusting roughly 900 square miles of land with about a tenth of a millimeter of snow above the minimal amount that was falling naturally.

The three cases highlighted in the study produced a combined total of 571 acre feet of water, or the equivalent content of about 285 Olympic-sized swimming pools.

Other cloud seeding attempts, however, were not so easily detected and may not have been successful. Tessendorf said the research team is continuing to analyze 18 additional attempts during SNOWIE in order to learn under what conditions the seeding effect can be detected and result in an increase in precipitation.

he results from SNOWIE can be used to improve computer models of cloud seeding processes and better inform officials as they make decisions about their particular priorities, Tessendorf said. Ski resorts might want to increase snow on selected days, whereas water managers would want to build up snowpack over the course of the winter in order to generate additional spring runoff.

“We’re going to need to dig deeper into the data and further quantify the seeding impact,” Tessendorf said. “It’s important to find out whether this enhances snowpack in a way that meets specific needs. ”

About the article

Title: Quantifying snowfall from orographic cloud seeding
Authors: Katja Friedrich, Kyoko Ikeda, Sarah A. Tessendorf, Jeffrey R. French, Robert M. Rauber, Bart Geerts, Lulin Xue, Roy M. Rasmussen, Derek R. Blestrud, Melvin L. Kunkel, Nicholas Dawson, and Shaun Parkinson.
Publication: Proceedings of the National Academy of Sciences

Thunderclouds building over the Rocky Mountains, shot as a short pano with an iPhone.

From Colorado Public Radio (Grace Hood):

The end result was a critical research finding: On three occasions, injecting clouds with silver iodide generated significant precipitation, more than doubling the rate of snowfall that had been falling naturally…

Cloud seeding is the deliberate injection of substances like silver iodide by airplane to create precipitation. The practice dates back to the 1940s when American chemist Vincent Schaefer used airplanes — and even cannons — to inject clouds with silver iodide or dry ice. While the industry around cloud seeding has existed for decades in the United States, the ability of science to verify results has been more ambiguous.

Scientists flew an airplane that had high-resolution cloud radar that could see features in clouds that are undetectable to the naked eye. Scientists also positioned mobile Doppler radars on wheels that storm chasers use high in the mountains above basins to observe changes in weather.

“Having these mobile radars positioned up on top of mountain ridges to be able to see over the basins where we were targeting cloud seeding, we were able to get measurements that we wouldn’t have seen otherwise,” [Sarah] Tessendorf said.

Eric Hjermstad, field operations director, Western Weather Consultants, lights a cloud seeding generator north of Silverthorne, Colorado. Photo credit: Denver Water

From KUNC (Luke Runyon):

A lot of the current water scarcity problems in the Southwest could be eased if it just snowed more and with a regular frequency in the high country of Colorado, Utah and Wyoming. More snow means more time to deal with the Colorado River’s fundamental supply and demand imbalance.

The onus to correcting that imbalance often falls more on the demand side of the equation, with myriad policy pushes that either incentivize or force people to use less water. On the supply side, options are limited.

There’s one tempting proposition for western water managers currently feeling the pressure to dole out cutbacks to users due to the region’s ongoing aridification — inducing clouds to drop more snow.

For decades, states have invested in weather modification programs, also known as cloud seeding, in the hopes of boosting precious snowpack. The practice showed up in a recent agreement among Colorado River Basin states, and investment is expanding, with water agencies in Wyoming and Colorado for the first time putting funds toward aerial cloud seeding, rather than solely relying on ground-based generators.

“I can say that we’re up significantly in the last 24 months on the number of smaller large-scale programs that we’re modeling and completing feasibility studies for,” says Neil Brackin, CEO of Weather Modification, Inc., a North Dakota-based cloud seeding company that operates across the Western U.S.

Brackin’s company is in charge of the Colorado and Wyoming aerial programs, flying cloud seeding operations when moisture-laden snow storms arrive in northern Colorado’s Never Summer range or southern Wyoming’s Medicine Bow and Sierra Madre ranges…

It’s not snowing when we visit the generator, but Hjermstad agrees to fire it up to demonstrate how it works. First, he gets propane flowing and then turns on a valve to the silver solution. With a fire starter, he lights the chimney on top. A bright orange flame flares from the generator, sending microscopic bits of silver iodide into the air.

If there was a storm right now and the wind was blowing the right direction, Hjermstad says, this generator could be influencing how much snow it eventually drops…

There is a certain class of clouds that are ripe for seeding, he says. Some clouds arrive in Colorado full of supercooled liquid water, but they’re not dropping that moisture. By injecting small particles into the cloud, a snowflake is able to form. The silver iodide acts as the “seed,” which enables the growth of a new ice crystal. That new snowflake can ricochet through the cloud, amplifying its impact…

From late November to April, Hjermstad keeps an eye on each weather system forecast to drop snow or pass over his generators. If it looks promising, he’ll contact the landowners where the generator sits, tell them when to turn it on and turn it off, and watch its track on radar with ground truthing courtesy of Colorado’s highway webcams.

For decades, the practice has had a problem with its reputation. Anecdotal accounts from farmers and ski resort owners confirmed cloud seeding effectiveness. Recent scientific studies have given it more credence, but top experts in the field argue there’s still a lot we don’t know about how well cloud seeding works…

Parked in a hangar outside Laramie, Wyo., we’re sitting inside the small research plane French uses to study clouds. To get to know a cloud, he says, you can’t just look at it from the outside, you need to get inside it. An expensive suite of on board instruments lets him look at how snow forms in real time.

“Ice crystals come in many many different shapes,” French says. “They can look like six-sided plates. They can look like long needles or columns. They can look like dendrites, which is kind of the typical snowflake shape.”

For years, French has devoted much of his research to understanding the science behind cloud seeding. In 2017 he partnered with the Idaho Power Company and other researchers to fly the research plane behind another plane that was seeding clouds. The result was a series of scientific articles. A 2018 report French co-authored showed for the first time how aerial cloud seeding worked…

The study, called “Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment” (SNOWIE) and conducted in the Payette River basin near Boise, Idaho, was a big deal. Before then, no one had solid evidence that showed the physics of cloud seeding working in the real world.

With new data in hand, French was able to say, “Yes, the amount of snow that was falling at this location increased.”

That might sound like a definitive endorsement of cloud seeding effectiveness. But the scientists producing the research are circumspect about their findings, and ready to caution people from taking away too much from SNOWIE’s early results…

Sarah Tessendorf is a researcher at the National Center for Atmospheric Research in Boulder, Colo. and worked with French on SNOWIE. People ask her frequently if cloud seeding works. And she says it depends on how you define “work.” If the question is whether or not cloud seeding is capable of producing more ice inside a cloud, then the answer is yes. But more often than not, the question is more complicated and people are hoping for more than that.

“So, sometimes the question … is, ‘Does it produce additional snowpack on the ground?’ And we’re still working to try to answer that question,” Tessendorf says.

Tessendorf is cautious about what she’s currently able to prove when it comes to cloud seeding. In the past, studies have shown the practice could boost snowpack by up to 15 percent. Tessendorf says the increase in snowpack cited in those studies has been a moving target over the years, with varying levels of rigorous data gathering. When she and other researchers want solid proof, they’re looking for a 95 percent level of confidence that cloud seeding caused the increase, and it wasn’t just a serendipitous series of storms…

In a gilded Las Vegas conference room in December 2017, water managers detailed their solutions to the Colorado River basin’s chronic water scarcity, and how to wean the Southwest from total reliance on the overtaxed river.

A representative from the Upper Colorado River Commission laid out what Colorado, Wyoming, New Mexico and Utah would bring to the table. A three-pronged Drought Contingency Plan included a focus on demand management, which would create a dedicated pool of saved water within Lake Powell. Another prong dealt with reservoir operations to streamline decision making between state and federal agencies. The third was a re-commitment to weather modification programs which had been in place in some form since 2007.

In mid-2018, before wrangling over Colorado River Drought Contingency Plans reached a fever pitch in the river’s Lower Basin, water agencies in California, Arizona and Nevada agreed to spend upwards of $1.5 million each year on cloud seeding programs in the watershed’s upper reaches.

“The reason that cloud seeding is being implemented on a relatively large scale in the Colorado River basin is it’s a very low-risk, high-reward scenario,” says Dave Kanzer, an engineer with the Colorado River District and manager of the Central Colorado Mountain River Basin Weather Modification Program, which receives funds from Lower Basin water agencies.

If you’re a water manager in the Southwest, it’s easy to think of cloud seeding like an extra battery for a smartphone. The guy selling the battery tells you it will probably only charge your phone another four or five percent, maybe more if you plug it in at exactly the right time. So it’s not reliable, but it’s the cheapest on the market. Every other battery is expensive and takes years to make. And if a lot of people are counting on you to make a call, you might just be willing to buy the battery, even if it ends up doing nothing in the end.

Kanzer says investors understand the risks involved with cloud seeding. They’re not under a delusion that it will be the basin’s saving grace…

Colby Pellegrino is with the Southern Nevada Water Authority, the water utility for Las Vegas, and says her agency’s investment in Upper Basin cloud seeding is worthwhile.

The University of Wyoming King Air (UWKA) research aircraft supports a large variety of instrumentation, and is configurable for measurements of cloud properties, air motion, turbulence and fluxes, atmospheric chemistry and aerosols. A research crew of three to four can typically be accomodated with an approximate four hour flight endurance and a maximum flight level of 28,000 ft. The UWKA has a payload capacity of up to 1,650 lbs, supporting the suite of instrumentation maintained by the UW Research Flight Center as well as user-supplied equipment. The UWKA is commonly configured to accomodate the University of Wyoming Cloud Radar (WCR) and University of Wyoming Lidar (WCL) systems.

Here’s a release from the University of Wyoming:

Two University of Wyoming researchers contributed to a paper that demonstrated, for the first time, direct observation of cloud seeding using radar and gauges to quantify the snowfall. Traditionally, cloud seeding — used to increase winter snowpack — has been evaluated using precipitation gauges and target/control statistics that led mostly to inconclusive results.

The research, dubbed SNOWIE (Seeded and Natural Orographic Wintertime Clouds — the Idaho Experiment), took place Jan. 7-March 17, 2017, within and near the Payette Basin, located approximately 50 miles north of Boise, Idaho. The research was in concert with Boise-based Idaho Power Co., which provides a good share of its electrical power through hydroelectric dams.

“This looks at how much snow falls out of seeded clouds at certain locations. That’s what’s in this paper,” says Jeff French, an assistant professor in UW’s Department of Atmospheric Science and fourth author of the paper. “We want to see if we can apply what we learned over a number of cases over an entire winter.”

The paper, titled “Quantifying Snowfall from Orographic Cloud Seeding,” appears in the Feb. 24 (today’s) issue of the Proceedings of the National Academy of Sciences (PNAS), one of the world’s most prestigious multidisciplinary scientific journals, with coverage spanning the biological, physical and social sciences.

The paper is a follow-up to a previous PNAS paper, by the same research team, titled “Precipitation Formation from Orographic Cloud Seeding,” which was published in January 2018. That paper focused on what happens in the clouds when silver iodide is released into the clouds. In the case of the SNOWIE Project, the silver iodide was released by a second aircraft funded through Idaho Power Co., while the UW King Air took measurements to understand the impact of the silver iodide, French says.

Katja Friedrich, an associate professor and associate chair of atmospheric and oceanic sciences at the University of Colorado-Boulder, was the newest paper’s lead author. Bart Geerts, a UW professor and department head of atmospheric science, was sixth author on the paper. Other contributors were from the University of Illinois at Urbana-Champaign, the National Center for Atmospheric Research (NCAR) and Idaho Power Co.

Throughout the western U.S. and other semiarid mountainous regions across the globe, water supplies are fed primarily through snowpack melt. Growing populations place higher demand on water, while warmer winters and earlier spring reduce water supplies. Water managers see cloud seeding as a potential way to increase winter snowfall.

“We tracked the seeding plumes from the time we put the silver iodide into the cloud until it generated snow that actually fell onto the ground,” Friedrich says.

French credits modern technology, citing the use of ground-based radar, radar on UW’s King Air research aircraft and multiple passes over a target mountain range near Boise, with making the detailed cloud-seeding observations happen. Despite numerous experiments spanning several decades, no direct, unambiguous observation of this process existed prior to SNOWIE, he says.

Over the years, research of cloud seeding “has been clouded,” so to speak, Geerts adds. He says it was difficult to separate natural snowfall and what amount was actually produced through cloud seeding. However, this study was able to provide quantifiable snowfall.

“Natural snowfall was negligible. That really allowed us to isolate snow added through cloud seeding,” Geerts says. “However, we are still in the dark where there is lots of natural snowfall.”

Following a brief airborne seeding period Jan. 19, 2017, snow fell from the seeded clouds for about 67 minutes, dusting roughly 900 square miles of land in about one-tenth of a millimeter of snow, based on the team’s calculations. In all, that cloud-seeding event and two more later that month produced a total of about 235 Olympic-sized swimming pools’ worth of water.

Other observations where snow from cloud seeding was measured took place Jan. 20 and Jan. 31 of that year.

In all, the UW King Air made 24 research flights or intense observation periods (IOPs) lasting 4-6 hours each during SNOWIE. Of those IOPs, cloud seeding occurred during 21 of the flights. During the last three flights, Idaho Power had to suspend cloud seeding because there was so much snow in the mountains already.

While a good deal of research took place aboard the King Air, much of it also occurred on the ground. Numerical modeling of precipitation measurements was conducted using the supercomputer, nicknamed Cheyenne, at the NCAR-Wyoming Supercomputing Center. The numerical models simulated clouds and snow precipitation — created in natural storms and with cloud seeding — over the Payette Basin near Boise. The numerical models also allow researchers to study future storm events where measurements have not been obtained in the field.

While the 24 cloud-seeding flights by King Air was a good start, Geerts says, in an ideal world, even more flights are necessary to learn more about cloud seeding in other regions of the country.

Friedrich adds that the research is an important first step toward better understanding just how efficient cloud seeding can be at creating those winter wonderlands.

“Everyone you talk to will say, even if you can generate a little bit more snow, that helps us in the long run,” she says.

French says the team has applied for a new National Science Foundation grant to continue analyzing cloud-seeding data collected from the remaining research flights during 2017.

“We will look at areas where natural snowfall occurs,” French says. “We’ll take what we learned and see if we can quantify how much snow was produced through silver iodide in areas already receiving snow.

“When we get done with the next three years, we’d like to go out and make similar-type measurements in Wyoming, Colorado or Utah, where clouds may have different characteristics,” French adds. “We can broaden the types of clouds we can sample.”

This video shows Drone footage from the top of Granite Peak in Idaho as we were digging out the Doppler On Wheels (DOW) mobile radar, RV trailer, and porta potties that were deployed for the Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) scientific field campaign. This site was called the “Snowbank” site during the project due to the roadway that leads to Snowbank Mountain just to the north of Granite Peak. I was the CU Boulder graduate student lead working with the Center for Severe Weather Research (CSWR) to operate the DOWs during SNOWIE.

To learn more about the SNOWIE project, check out the links below:
https://www.eol.ucar.edu/field_projec…
http://www.cswr.org/projects/snowie/

The January 2020 newsletter is hot off the presses from the Water Information Program

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

Demand Management – a Hot Topic!!
There was an in-depth conversation around the Demand Management topic!

Celene Hawkins stated that the Demand Management workgroups are just at the beginning stages of work and there are still many questions. There is a greater need for coordination and keeping a steady pace of the work, while not moving too quickly so as to not miss things, as these are very complicated issues and need to take that time that is needed to do the work. There will be a joint IBCC and Demand Management work-group meetings that will take place March 4-5 where discussion could take place about that better coordination and how the CWCB can support the work-groups moving forward.

Russell George stated that the IBCC is not a work-group in Demand Management, they intentionally stand aside because they wanted to be ready as the IBCC to pick any particularly thorny question with the statewide implication that needed their help. The IBCC believes that at this point in time, and because of what’s going on with the river as a whole and the water levels of the big reservoirs, Demand Management becomes probably one of the most important issues for discussion on Colorado water issues that there is today. George explained that we owe it to the other Upper Basin states who are going through this drill, to work together to find an approach that works in all four states or to learn together that Demand Management can’t be done. Whatever conclusion is reached, it needs to be based on open and careful consideration of Demand Management as a tool that is being evaluated, as called for in the Drought Contingency Plans and Legislation.

Southwestern Water Conservation District Area Map. Credit: SWCD

As the Southwest dries out, water managers increasingly look to cloud seeding — The Durango Herald

Cloud seeding ground station. Photo credit H2O Radio via the Colorado Independent.

From The Durango Herald (Jonathan Romeo):

For decades, Western states have tried to offset long-term drying trends and dwindling water supplies of the region by sending up a specialized concoction into the atmosphere as winter storms approach, which proponents say boosts snowfall.

Across a sliver of Colorado from Telluride to Pagosa Springs, a total of 36 cloud-seeding generators are strategically placed, typically 5 miles apart, to cover a wide range of the high country of the San Juan Mountains for this purpose.

In 2020, the Southwestern Water Conservation District has set aside $27,000 for a new remote generator. While the station’s location is being decided, the aim is to place it at a higher elevation site where there is a gap in the network of generators.

“The majority of our water supply comes from snowpack, so if we can provide any additional amount, it has a huge benefit to our basin,” said Frank Kugel, executive director of SWCD, which represents nine counties in Southwest Colorado.

Waters managers who rely on the Colorado River are dealing with an array of issues as more people move into the region and demands increase on a waterway that is seeing less water every year because of issues directly related to climate change.

In adapting to this new reality, cloud seeding, they say, is just one part of the attempted solution…

Does it work?

How much additional snow falls as a result of cloud seeding has been a hot topic among water managers for years, and most agree, more detailed research needs to happen to pin down just how much additional snow is extracted from the practice.

Yet, most accept an estimated range between 2% to 15% more snow per storm.

Statewide, about $1.2 million is spent annually toward cloud seeding, with money coming from local and state water districts, as well as lower basin states that rely on the Colorado River, said Andrew Rickert, program manager for the Colorado Water Conservation Board.

Supporters of the project have said that for every $1 in cost, about $3 worth of water is produced…

The future

Better technology, more generators in high-elevation spots and more stations in general are the top priority with cloud seeding going further.

Experiments have been conducted in recent years that show releasing silver iodide by plane gets more out of storms, but the practice is expensive, and cost-prohibitive, Kugel said.

Southwestern Water Conservation District, along with its partners, will take the coming weeks to find the best spot for the new remote generator in the region. The district spends about $117,000 on the entire cloud-seeding effort in the region.

Cloud-seeding graphic via Science Matters

The latest “The Current” newsletter is hot off the presses from the #EagleRiver Watershed Council

Photo credit: Eagle River Watershed Council

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

Cloud Seeding Discussion with Colorado River District

A big thank you to our presenters, Dave Kanzer with the Colorado River District and Eric Hjermstad with Western Weather Consultants for a great community discussion. We had about 50 folks join us at Loaded Joe’s to learn about the weather modification tool being implemented locally.

Missed it? You can watch a recorded version here thanks to High Five Access Media and the underwriting of Eagle River Water & Sanitation District!

Cloud-seeding graphic via Science Matters

The San Juan Water Conservancy District ponies up $1,000 for cloud-seeding research

State cloud seeding programs. Graphic credit: The Huffington Post

From The Pagosa Sun (Chris Mannara):

Following a presentation earlier in the day, the San Juan Water Conservancy District (SJWCD) Board of Directors opted to see if ef- forts from cloud seeding could produce any re- sults that could be seen locally before providing funding to cloud seeding efforts.

The cloud seeding presentation was given to the board during a work session on Tuesday by Eric and Mike Hjermstad from Western Weather Consultants LLC, and following the work ses- sion, the board had a possible action item on whether or not to fund cloud seeding efforts for the southwest basin.
In the draft budget, the SJWCD has $1,000 set aside for potential cloud seeding funding…

The effectiveness and amount of extra moisture that is produced by cloud seeding ef- forts has been debated for years, SJWCD board member Al Pfister noted…

[Bill] Hudson later made a motion that suggested the SJWCD look into whether or not it could help finance the research of cloud seeding operations in the district’s watershed and would task SJWCD consultant Renee Lewis to conduct this project. The motion passed unanimously.