Radiometer near Mancos used to forecast cloud-seeding potential

April 5, 2014
Calibrating the radiometer via The Durango Herald

Calibrating the radiometer via The Durango Herald

From The Durango Herald (Mary Shinn):

On Monday meteorologist, Marta Nelson, installed a temporary radiometer at Jackson Lake near the Mancos Water Conservancy District. The instrument is able to determine the best combination of water content in clouds and temperature to use a cloud-seeding generator.

Cloud-seeding generators throw up silver iodide into the atmosphere to harvest the extra water because snow will form around it.

“We can see relative humidity and vapor and the potential for a cloud to form. We can also see inside a cloud that’s already formed, so if we’re looking for liquid water versus ice that is frozen in the cloud the radiometer can tell the difference and help tell the cloud-seeding people when to run the generators or when it’s not going to do any good,” she said. Nelson works for Radiometrics Corp., based in Boulder, which installs similar machines all over the world.

The new data also will help scientists decide if the local cloud-seeding generator at Spring Creek should be run later into the winter season, said Jeff Tilley, director of weather modification at the Desert Research Institute in Reno. The institute operates the local cloud-seeding generator remotely. The data collected over the next month will be applied to operations next winter because the Spring Creek generator is almost out of cloud-seeding solution, he said.

The institute is collaborating with the Colorado Water Conservation Board on the project, and the board is paying the $8,500 to lease the radiometer for a month.

Across the state, about $1 million is spent on cloud seeding, and about 65 percent of the funds are provided by local entities such as ski areas, water districts and towns. The other 35 percent of the funds are provided by state and other funding.

The generator near Mancos has been in place for about five years, and in that time, there has been some benefit in the area, Tilley said.

“The impression we have is that we have seen some difference,” he said.

Cloud seeding is safe because silver iodide won’t break down in any way that’s harmful, Nelson said.

More cloud-seeding coverage here. More San Juan River Basin coverage here.


Ski areas, et. al, kick off this winter’s cloud-seeding program

October 17, 2013
Cloud-seeding graphic via Science Matters

Cloud-seeding graphic via Science Matters

From the Colorado Independent (Bob Berwyn):

In Colorado, ski-area operators and water managers have been known to do a few rain dances and — privately at least — pray to their own God when drought strikes. But in the age of technology and hubris, when nearly every challenge is met with engineering, they aren’t just waiting for Mother Nature to put her cards on the table. Instead, there’s a growing interest in seeding clouds with silver iodide to coax every possible bit of moisture from passing storms.

Weather modification has historic roots in the Cold War era, when both the U.S. and Soviets looked at ways to weaponize weather, and more recently, U.S. intelligence agencies decided to help fund a far-reaching study aimed at determining if there’s a way to mitigate global warming with technology and engineering.

Proponents have claimed for years that seeding can increase snowfall in targeted areas by as much as 15 percent. As a result, water providers like Denver Water, and big ski resorts, including Vail, Breckenridge and Winter Park, are all helping fund a $1 million cloud-seeding program in Colorado’s north-central mountains, hoping to improve ski conditions, as well as boost stream flows and reservoir storage.

Recent news about record-low flows from Lake Powell, the key Colorado River reservoir, has spurred even more interest in enhancing natural precipitation, said one of the state officials who manages what’s formally called a weather modification program. A roster of companies involved in cloud seeding and related activities shows that weather modification is a growth industry.

The state program is run by the Colorado Water Conservation Board, which issues permits and sets basic rules — for example cloud-seeding stops when the snowpack reaches a certain level to address concerns about avalanches and flooding.

But those rules haven’t quelled concerns, as there are still a few people left who probably think that tinkering with the weather on a large scale is probably one of the worst ideas ever. Those sentiments were reflected during a hearing for cloud seeding permits in the early 2000s. Residents of Evergreen turned up en masse to claim that, ever since Vail started seeding clouds (way back in the 1980s), snowfall in their town has declined.

The CWCB program was jump-started with state seed money in the early 1970s, but since then has become 80 percent – 90 percent self-funded through grants and participation by resorts and water providers, with everyone seeing cloud-seeding as a low-cost alternative to building new reservoirs and pipelines. And with an uncertain outlook for Colorado River flows, even downstream states like Arizona and California are ponying up to help pay for cloud seeding in the headwaters.

The question about downwind impacts seems reasonable. After all, there’s only so much moisture in every cloud. But weather experts like Colorado state climatologist Nolan Doesken say there’s not a shred of evidence to show that cloud-seeding affects snow and rainfall downwind of the specific target areas. The weather pattern most suitable for mountain cloud seeding (a steady, moisture-laden jet stream out of the northwest) generally leave the plains high and dry.

On the other hand, Doesken said there’s no clear evidence to show that seeding enhances snowfall anywhere near the amount claimed.

“If it really increased snowfall by 15 percent, you’d be able to see that in streamflow records from, say, the Gunnison Basin (where seeding has been ongoing for many years), but that’s not the case,” Doesken said. Overall, he believes that seeding does boost precipitation, but by a lesser amount than claimed…

So when your score your first face shots this coming winter, go ahead and enjoy the celebratory bonfire in honor of Ullr, the Norse god of skiing. But just to be on the safe side, don’t forget to raise your glass in a toast the men and women who promise better living — including more snow — through chemistry and engineering.

More cloud-seeding coverage here and here.


Cloud-seeding program for the central mountains for this season ended on April 10 #COdrought #ColoradoRiver

May 1, 2013

cloudseedingexplained.jpg

From the Summit County Citizens Voice (Bob Berwyn):

While the winter’s biggest snow totals came after the end of this year’s program, the seeding operations may have helped bring near-average snowfall to area in February and March, according to the operators, who are now measuring their efforts under a “target and control” evaluation that will be submitted to the Colorado Water Conservation Board for review.

Durango-based Western Weather Consultants, which seeds the central mountains, was able to extend operations into early April and use all its allotted operational days, said Larry Hjermstad. During the 2012-2013 season, the central mountains program cost $293,600 and targeted an area of about 1,668 square miles of the Upper Colorado River Basin, generally above elevation 8,500 feet, in parts of Pitkin, Eagle, Summit, and Grand counties. Front Range water providers and ski areas, along with other partners, help fund the program, aimed at enhancing water supplies and boosting ski conditions at A-Basin, Breckenridge, Keystone and Winter Park, all included in the target area…

In past seasons, Hjermstad estimated that cloud-seeding may have boosted snowfall by as much as 15 percent in targeted areas.

Cloud-seeding efforts in Colorado have a long, on-and-off history dating back to the 1970s, when the federal Bureau of Reclamation was active in the southwestern mountains, said state climatologist Nolan Doesken, who acknowledged that there is still a debate about the effectiveness of cloud-seeding. Doesken said that there is good evidence that cloud-seeding can work in the right conditions, with very specific requirements as to wind direction, moisture and temperatures. Outside that range, the results are less clear.

Funding comes from the Front Range Water Council including Aurora Water, Denver Water, Colorado Springs Utilities, Northern Colorado Water Conservancy District, Twin Lakes Reservoir & Canal Company, Southeastern Colorado Water Conservancy District, and Pueblo Board of Water Works. The Colorado River Water Conservation District, A-Basin, Keystone, Breckenridge, and Winter Park also participate.

The Colorado Water Conservation Board and the Lower Basin States, including the Southern Nevada Water Authority, Central Arizona Water Conservation District, and California Six Agency Committee also help fund the cloud-seeding, but don’t directly participate in the program, said program manager Maria Pastore, of Glenwood Springs-based Grand River Consulting.

More cloud-seeding coverage here and here.


Grand Mesa cloud-seeding program history and results #ColoradoRiver

April 9, 2013

cloudseedingexplained.jpg

From the Grand Junction Free Press (Sharon Sullivan):

For 50 years, humans have attempted to modify the weather for the purpose of increasing snowpack, to fill up reservoirs, reduce hail, and even prevent rain. The scientific practice of cloud seeding has been utilized on Grand Mesa since the 1990s. Two years ago, the Water Enhancement Authority stepped up its Grand Mesa program by doubling the number of cloud seeders to 16. “We’re trying to increase snowpack on the Mesa, to fill up the reservoirs,” said Mark Ritterbush, the Grand Junction water operations supervisor and secretary for the Water Enhancement Authority (WEA).

The WEA is comprised of the City of Grand Junction, Powderhorn Ski Mountain Resort, Collbran, the Grand Mesa Water Conservancy District, and Overland Ditch and Reservoir Company. Funding for the cloud-seeding program comes from those entities, as well as Delta County, the Colorado River District, the Colorado Water Conservation Board and lower Colorado River basin states.

Meteorologists determine where to place the cloud-seeding machines on the Mesa. Oftentimes, they’re located on private property where landowners are paid rent to host the machines.

In China, cloud seeders — many of them farmers — are paid to use anti-aircraft guns and rocket launchers to release pellets containing silver iodide into clouds, according to Wikipedia. Other areas disperse the precipitation-enhancing agents via airplanes.

On the Grand Mesa, cloud-seeding machines consist of tanks on the ground filled with a silver-iodide solution containing chemicals such as acetone. The solution is sprayed across a propane-fueled flame, causing the particles to drift with the wind current up into the cloud. The condensation nuclei turn into ice crystals, ride along with the cloud and fall out as a snowflake. Silver iodide is used because its crystalline structure is almost identical to ice, Ritterbush said.

“A meteorologist (John Thompson of Montrose) watches storms as they come in,” Ritterbush said. “He calls and tells (the landowners) when to turn it on. Rarely are all 16 cloud seeders running at the same time.”

IS CLOUD-SEEDING EFFECTIVE?

There is an ongoing debate regarding the effectiveness of cloud seeding versus letting nature take its course, Ritterbush said. Ten years ago, the National Academies of Science released a report saying, that after 30 years of research, there is no convincing proof of intentional weather modification efforts. “In nature, it’s hard to set up an experiment with a control,” Ritterbush said. “It’s a conundrum how to compare.”

Yet, studies suggest cloud seeding can increase snowpack 5 to 15 percent, which makes the program’s annual cost of between $30,000 and $40,000 cost-effective when you factor in the extra water, Ritterbush said. The cost variable is due to weather conditions, how often seeding takes place, and the cost of silver, Ritterbush said. According to the World Meteorological Policy Statement, “a well-designed, well-executed program shows demonstrative results,” said Joe Busto, who runs the weather modification permitting program out of Denver for the Colorado Water Conservation Board.

The Grand Mesa has been a forum to introduce new equipment and different seeding technologies, Busto said. The topography is ideal for setting up cloud-seeding machines at a high elevation, he said. “There’s a rich history of research on the Grand Mesa, during the ’70s, ’80s, and ’90s,” Busto added.

Arlen Huggins, a semi-retired research scientist with the Desert Research Institute in Reno, Nev., is familiar with the Grand Mesa project. Huggins said there is plenty of convincing evidence that modifying weather is effective for increasing precipitation. He mentioned prior Bureau of Reclamation studies, plus a recently completed five-year experiment in Australia. “There’s a lot of evidence related to snowfall enhancement,” Huggins said. “It makes it a viable option for increasing water supply.”

The Water Enhancement Authority is in the process of collecting data comparing seeded areas versus non-seeded areas on the Mesa, Ritterbush said.

ENVIRONMENTAL RISKS?

So, what happens when silver-iodide particles hit the ground or land in lakes or rivers? While there has been no monitoring for silver in western Colorado’s environment, researchers in Australia have spent millions searching for traces of the mineral, Ritterbush said. In Australia, where lake beds and soils have been tested, they “just don’t find it near toxic levels,” Busto said.

Huggins, who is considered a cloud-seeding expert, said he’s often asked about potential risks of silver toxicity in the environment. “It’s a minuscule amount of silver being released,” Huggins said. “The silver iodide amounts released are not harmful. (The particles) are not soluble in water. It cannot be taken up by aquatic species. It does not bio-accumulate.”

There are approximately 106 cloud-seeding sites in Colorado, including Summit County, Gunnison, Telluride and the Dolores area, the West and Eastern San Juan mountains. Vail and Beaver Creek have the oldest program, having cloud-seeded for 38 years. Most permits are issued from November through March and sometimes into mid-April, Busto said. “We monitor snowpack, avalanche hazards, and suspend programs when needed,” he said.

A 2010 statement from the American Meteorological Society states that “unintended consequences of cloud-seeding, such as changes in precipitation or other environmental impacts downwind of a target area have not been clearly demonstrated, but neither can they be ruled out. Continued effort is needed toward improved understanding of the risks and benefits of planned modification through well-designed and well-supported research programs.”

More cloud-seeding coverage here and here.


Cloud-seeding rules may help to determine the efficacy of the various delivery methods #CORiver

December 8, 2012

cloudseedingexplained.jpg

From the Summit County Citizens Voice (Bob Berwyn):

As part of the state-authorized weather modification plan, operators of cloud-seeding operations are required to complete annual “target versus control” analyses, comparing snowfall in target areas against similar non-targeted control areas. Over time, the data from those evaluations may help determine if cloud seeding really does boost snowfall by up to 15 percent, as claimed by the operators.

“This method is credible and develops relationships between snow data and tracks precipitation totals over time in both seeded areas and non-seeded areas to help track the efficacy of the program,” said Maria Pastore, of Glenwood Springs-based Grand River Consulting, who manages the central mountains cloud-seeding rogram.

“In addition, the State has new data types and evaluation methods suggested for cloud seeding programs,” Pastore said. “They are not required but are suggested as good periodic evaluations that can help the long-term sustainability of these programs.”

Cloud seeding in Colorado involves burning silver iodide in ground-based generators to inject tiny particles of the material into approaching weather systems. The silver iodide is said to provide nucleii for crystal formation and growth, helping to wring a bit of additional moisture from the clouds.

For the 2012-2013 season, the central mountains program will cost $293,600 and target an area of about 1,668 square miles of the Upper Colorado River Basin, generally above elevation 8,500 feet, in parts of Pitkin, Eagle, Summit, and Grand counties. If it works, the program could benefit A-Basin, Breckenridge, Keystone and Winter Park, all included in the target area.

More cloud-seeding coverage here and here.


Drought news: Public hearing tonight for Western Weather Consultants’ cloud-seeding application

September 24, 2012

cloudseedingexplained.jpg

Here’s the notice from the CWCB website:

The CWCB has received an application from Western Weather Consultants to renew their permit for a wintertime ground based cloud seeding program on behalf of Denver Water and Colorado Springs Utilities and several other sponsors.

This notice of intent has been advertised in eighteen newspapers in eighteen counties for this public hearing.

The public hearing will be held at La Quinta Inn & Suites, Loveland Room, 560 Silverthorne Lane, Silverthorne, Colorado, at 6:00 PM on Monday September 24, 2012.

The public record will be held open so that comments can be emailed to joe.busto@state.co.us or mailed with postmark of October 1, 2012 for consideration as part of the record of decision.

Public comments oral and written are used by the State to develop a record of decision that is used to deny, approve, or approve with special terms and conditions a weather modification permit.

More CWCB coverage here.


Gunnison County files application to continue cloud seeding program for another ten years

September 7, 2012

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From The Chaffee County Times (Casey Kelly):

North American Weather Consultants has filed an application with the Colorado Water Conservation Board for a 10-year renewal of its cloud seeding program in Gunnison. According to the group, Chaffee County could benefit from additional water from the program.

Since 1950, NAWC has been conducting weather modification programs in the western United States and has been cloud seeding in the Gunnison area for the past 10 years. The purpose of the operation is to increase precipitation and snowpack in the area for agriculture, municipal water, recreation and tourism.

Current cloud seeding programs in Colorado:

Central Colorado Rocky Mountains Program (Denver Water and Winter Park)
Upper Roaring Fork Basin Program (Colorado Springs Utilities)
Vail/Beaver Creek Program (Vail/Beaver Creek Ski Areas)
Gunnison River Basin Program (Gunnison County, Upper Gunnison River WCD)
Grand Mesa (Water Enhancement Authority which is comprised of Collbran WCD, Fruitland Mesa WCD, Crawford WCD, Grand Mesa Pool)
Western San Juan Mountains Program (Southwestern WCD, City of Durango, Animas La Plata WCD, Durango Mountain Resort, Dolores WCD)
Eastern San Juan Mountains Program (Pagosa Area Water and Sanitation District, San Juan WCD, Southwestern WCD)

More cloud seeding coverage here and here.


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