Cloud-seeding is gaining acceptance

From the SummitDaily (Jack Queen) via The Aspen Times:

[Larry] Hjermstad and his company, Western Weather Consultants, now run cloud seeding programs across the state, including in Summit County.

For decades, local ski areas have paid him to send plumes of silver iodide up to their slopes when opportune storms approach, squeezing out a couple of extra inches of snow each time.

In recent years, however, water managers on the Front Range and even states further down the Colorado River have started to pitch in some of the $250,000 to $300,000 it costs to run the program in the Summit County area, hoping the extra snow will flow into their water system when it melts.

Here, in the Central Colorado Mountains River Basin, the company operates about 36 cloud seeding generators. They’re small, almost homebrew-looking devices that burn a solution of inert silver iodide and send it into the atmosphere.

Some of the generators are on private land, and when Western Weather Consultants detects an optimal storm coming, it sends instructions to the landowners to fire them up. It varies, but Hjermstad says the process can boost snowfall by as much as 25 percent…

SNAKE OIL OR SCIENCE?

The concept of cloud seeding has been around since the 1940s, when Bernard Vonnegut (brother of author Kurt) discovered that silver iodide could produce ice crystals when introduced into cloud chambers.

In those heady days, cloud seeding was heralded as a way to produce rain where there was none, boosting crop yields and filling reservoirs to the brim.

That was a wild overstatement, and cloud seeding’s reputation suffered for it…

Studies in Australia and Israel have debunked the idea that airplanes spewing silver iodide willy-nilly will do much of anything. But a targeted approach that hits the right clouds at the right time high in the mountains has gained scientific currency in recent years.

Rio Grande Roundtable meeting recap

Cloud-seeding graphic via Science Matters

From The Alamosa News (Ruth Heide):

Although there are currently no cloud seeding operations in the San Luis Valley, some folks believe this might be a good place for it.

Joe Busto, who oversees weather modification permits for the Colorado Water Conservation Board, gave the Rio Grande Roundtable group a crash course on cloud seeding during its Tuesday meeting. The Valley-wide water group funds many water related projects in the Rio Grande Basin from ditch repair to reservoir rehab. The group was not asked for funding at this time.

Busto said that another form of weather modification, hail cannons, previously operated in the San Luis Valley under a permit with Southern Colorado Farms, but the agricultural operation discontinued the practice.

Cloud seeding occurs all around the region from Texas to North Dakota, Busto stated.

Many of the cloud seeding operations in Colorado are associated with ski areas such as Vail, Crested Butte and Breckenridge, Busto explained. Others are connected to water districts. There are currently 110 machines in the state. He described the primary catalysts as either silver iodide, which is expensive but effective (and not harmful to the environment), or propane, which is cheaper.

Before setting up a machine, plume dispersion tests are conducted to determine how the winds are blowing and from what direction so the cloud seeding operation can be set up to provide the most good.

Operations are also the most effective when machines are set up at higher elevations, Busto explained.

Roundtable member Travis Smith asked, “Is the Rio Grande ready to start participating in a winter time cloud seeding program?”

Roundtable member Charlie Spielman said he saw this as a solution to the imbalance between water supply and demand.

“Cloud seeding is the best opportunity within our reach of making a real dent in that supply/demand gap,” he said.

He encouraged “getting a program going here … Let’s put something into this because I think this is our best chance.”

Busto said he believed a lean cloud seeding operation could be put in place for about $60,000 a year. He said he believed there could be many benefits to this area as well as downstream.

#ColoradoRiver: The @CWCB_DNR is installing a ceilometer in Winter Park #COriver

Winter Park via MyColoradoLife.com.
Winter Park via MyColoradoLife.com.

From The Sky-Hi Daily News (Travis Poulin):

At their October 4 meeting, the Winter Park Town Council passed a motion to allow a ceilometer to be installed on the roof of the Winter Park Town Hall. . A ceilometer is a device that uses a laser to determine the height of a cloud base.

The town received a request from the Colorado Water Conservancy Board (CWCB), Denver Water and Winter Park Resort to place the device on the Town Hall building to aid them in their cloud seeding program. It will detect multiple layers of cloud height as well as measure the liquid water available in the clouds. The ceilometer will allow them to provide better forecasting for the cloud seeding program.

In addition to the cloud seeding program, this device will be available to pilots flying into Grand County. The pilots can determine the base elevation of the clouds as they approach the runway at the Granby/ Grand County Airport. The ceilometer is approximately four feet tall and would be attached to an existing concrete pillar.

The ceilometer will need electricity and Internet service. The electricity usage is approximately 5 amps per month (about 55 cents per month). The data usage is approximately a half a megabyte per month. The additional Internet service would not require upgrades as the current system has adequate space.

The Winter Park Town Council, CWCB, Denver Water, and Winter Park resort are now in the process of drafting a Memorandum of Understanding (MOU) for the installation of the ceilometer. The council also determined they will need a lease agreement for the project.

CLOUD SEEDING IN GRAND COUNTY

There are currently two cloud seeding generators in Grand County—one to the north of the Younglife camp at Crooked Creek Ranch, and the other near Churches Park in Fraser. The generators are remotely operated and controlled from Reno, Nev. They have been in place since 2009.

The Desert Research Institute (DRI) runs the cloud seeding program. According to their website, DRI currently has five cloud seeding operations: the San Juans (Mancos) Project, the San Miguel (Telluride) Project, Tahoe and Truckee basins, Walker Basin, and the Winter Park/ Denver Water Project. The purpose of the program is to augment snowfall in mountainous regions that supply water to northern and southern Nevada, and increase the snowpack and resultant runoff from the targeted basins.

According to DRI website, ground-based generators are used to burn a solution of silver iodide, sodium iodide, salt and acetone to release microscopic silver iodide particles which can create additional ice crystals, then snow, in winter clouds. Weather conditions are selected to optimize fallout in targeted basins. Generators are remotely operated by telephone landline, by radio or by other types of wireless communication. A seeding aircraft is frequently used to augment ground seeding operations. The aircraft releases AgI from wing-mounted solution burners. Dry ice is also used occasionally to seed shallow cloud systems, including fog over airports.

According to the website, benefits vary with the seasonal frequency of suitable weather opportunities. Research results have documented precipitation rate increases of a few hundredths to about two millimeters per hour due to ground-based seeding during the proper weather conditions. Based on the rate increases, estimates of augmented snow water from the DRI seeding program have varied from 20,000 to 80,000 acre-feet annually over the past 15 years of operation.

Seasonal percentage increase estimates have varied from two percent to ten percent The cost of augmented water, based on the annual cost of the program, has ranged from $7 to about $18 per acre-foot, according to DRI.

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

#ColoradoRiver: Remote-operated cloud seeder being installed above Dolores — KOAA.com #COriver

instumentationcloudseedingresearchcolorado

From the Associated Press via KOAA.com:

A remote-operated cloud-seeding generator is being installed in the mountains above Dolores in an attempt to improve snowpack and runoff into McPhee Reservoir.

Cloud seeders emit plumes of silver iodide into winter storm clouds to coax additional precipitation from clouds.

There are about 30 cloud-seeding generators stretching in an arc from Telluride to Mancos to Pagosa Springs. Most of the units are 40-year-old designs and require an operator to turn them on and off when conditions warrant.

The Cortez Journal reports that the Dolores Water Conservancy District has partnered with the Idaho Power Co. and Colorado Water Conservation Board on the project. Idaho Power has developed a more efficient remote-controlled generator that can be placed in locations higher in the mountains and closer to the clouds they seed.

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

Cloud seeding: “It can’t replace dams or conservation” — Joe Busto

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From the Watch (Stephen Elliott):

[Andy VanDenBerg] is one cog in a regional cloud seeding program that purports to increase wintertime snowfall over Telluride by as much as 15 percent; he’s one of the dozen or so landowners from Dolores to the southwest to Disappointment Creek and Saltado Creek further north who have allowed Durango-based Western Weather Consultants to install cloud-seeding generators on their properties, and are paid to operate them when a promising storm system moves into the area.

“It doesn’t make much money. It’s kind of a waste of time and an inconvenience,” VanDenBerg said. “But there’s a chance it works.”

It’s difficult — nearly impossible — to prove wintertime cloud seeding’s efficacy, but that hasn’t stopped the Telluride Ski & Golf Company, Dolores Water Conservancy District, Southwestern Water Conservation Board, Colorado Water Conservation Board, California Six Agency Committee, Central Arizona Water Conservation District, Southern Nevada Water Authority and Metropolitan Water District of Southern California from funding cloud seeding in the Upper San Miguel Drainage Basin, specifically on the Telluride Ski Resort.

“We’re in a 15-year drought and reservoirs are down, so we’re trying to help prevent them from going down further, and maybe bring them back up a little bit,” said Bill Hasencamp, Colorado River Resources Manager for the Metropolitan Water District around Los Angeles.

Hasencamp, like VanDenBerg, can’t be sure cloud seeding works (or at least how well it works), but his agency still enthusiastically funds the program. “There’s a general feeling that it increases snow, but no absolute proof. That’s the tough part: It’s very difficult to tell exactly,” he said.

All of the water managers involved in the Colorado cloud seeding program cite a study from Wyoming when discussing the effectiveness of cloud seeding. The study, conducted by the National Center for Atmospheric Research and several other organizations, was completed in 2014 and compared two mountain ranges in the state: the Medicine Bow and the Sierra Madre. For 10 years, researchers randomly seeded storms in one of the ranges, but not the other, in an attempt to discover if cloud seeding increased snowfall.

That study indicated a 5-15 percent snowfall increase, presumably due to cloud seeding.

“There’s not really any downside to [cloud seeding],” said Joe Busto, cloud seeding program manager with the CWCB. “It doesn’t do a lot, just a few inches more here and there. It can’t replace dams or conservation; it’s just a thing we do every year and we get a little more and that’s all it is.”

[…]

Water managers could conceivably seed clouds anywhere along the Colorado River Basin but have decided to partner with ski areas to boost recreational economies and take advantage of the funding those ski areas are willing to put up for the program.

“Although the state supports [cloud seeding], it’s not just because we want to support all the ski areas. This is a new water source, but it has the great benefit of helping out our recreational economy in Colorado,” said April Montgomery, a San Miguel County-based representative on the CWCB. “This is also a huge benefit to Norwood and the West End. We’re producing more water for our Telluride headwater reservoir, and that’s all going down to the lower ends of the San Miguel, into the Dolores, into the Colorado.”

As reservoirs along the Colorado River, including Lake Powell and Lake Mead, have dried up during the past few years, water managers downstream have turned to more experimental ways to keep them full, or at least less empty. Busto at the CWCB said the out-of-state agencies have contributed nearly $2 million to the Colorado cloud seeding program since 2007.

“The reason why the state is involved in cloud seeding is because it’s the cheapest form of new water. If you look at other ways of creating new water sources, you’re looking at desalinization or you’re looking at giant reservoir systems and new diversion systems. That costs so much money,” Montgomery said. “Our snowpack is the largest reservoir we have and if we can increase our snowpack, we are basically creating this giant reservoir that we can use later.”

[…]

But cloud seeding raises questions. Does silver iodide negatively impact the watershed once it falls out of the clouds? If we coax precipitation from clouds over Telluride, does that mean less will fall on other communities?

Cloud seeding proponents answer a resounding “No” to both questions.

The Wyoming study found silver concentrations in the water after cloud seeding in the parts per trillion range, and in the parts per billion range in soil, “about three orders of magnitude less than values considered hazardous to environmental system or human health.”

“Silver iodide doesn’t dissolve into the water,” Montgomery said. “One reason I’ve been able to embrace this technology is, as we improve and we’re being more efficient and effective with it, we’re not just throwing this up into the atmosphere.”

“This is something that doesn’t bioaccumulate,” Busto added. “When a chemical gets in the fish, then the eagles get it… That’s bioaccumulation. It’s a concern, but [silver iodide] won’t do that.”

As for cloud seeding’s effect on nearby areas, Western Weather’s founder Larry Hjermstad, who has been working in weather modification for four decades, said seeding merely takes advantage of an opportunity in a storm.

“One of the big concerns is, if we’re putting more precipitation in one area, it’s at the expense of another area. The answer is no; we’re creating a slightly better storm system,” he said.

Busto added that winter storms are typically large, often 200 miles long or more, and contain huge amounts of moisture, only a small amount of which will ever fall as precipitation. So when cloud seeding urges slightly more of that moisture out of the clouds, the vast majority of a storm’s moisture remains to fall elsewhere or stick around in the cloud.

“To say you took all the water out of a system that was 200 miles long is really a stretch,” Busto said. “Did you steal that [precipitation] from someone else? No, I don’t think so.”

The Wyoming study concurred, finding that the “downshadow effect,” or the impact of cloud seeding on areas outside the seeded area, was negligible.

#ColoradoRiver: Cloud-seeding supporters are hopeful efforts will fill aquifers and reservoirs — The Durango Herald

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From The Durango Herald (Mary Shinn):

To seed a cloud in Southwest Colorado, employees with Western Weather Consultants light generators that send vaporized silver iodide up to the base of clouds. The silver iodide forms an artificial ice nuclei and attracts supercooled water to form snowflakes.

In an ideal situation, the cloud would release excess water that would otherwise pass over the region, said Eric Hjermstad, co-owner and director of field operations for the company.

“It’s meant to add just a little bit more per storm,” Busto said.

A study in Wyoming conducted from 2005 to 2014 found cloud seeding can add 5 to 15 percent more precipitation.

During a dry storm or a dry year it’s harder to make a difference, he said.

Seeding during El Niño can help build snowpack to replenish aquifers and help fill reservoirs such as Lake Powell, Hjermstad said.

It’s an investment that is supported by regional water agencies and ski resorts that paid $237,900 this season, according to the Southwestern Water Conservation District. In this area, Western Weather operates about 36 generators from Pagosa Springs to Telluride, Hjermstad said.

This winter, the cloud-seeding supporters are looking to upgrade their efforts through better generators and potentially a radiometer that helps gauge the water and temperature of clouds before seeding, said Ken Curtis, engineer for the Dolores Water Conservancy District.

While he said there’s always skepticism around cloud seeding, the Wyoming study showed that cloud seeding can work if the silver iodide is delivered in the right place under the right conditions.

“We know it works, but you need to do best practices,” Curtis said.

Last week, the Southwest Basin Roundtable granted the group about $55,600 to hire a consultant to help select equipment and the right areas to place it.

The state will review and finalize the grant in the coming months, he said.

The strategic plan to upgrade equipment will likely take two years because there are 12 agencies and companies involved in funding.

#ColoradoRiver: Cloud-seeding impact to SW #Colorado

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From the Associated Press via The Denver Post:

A researcher with the Colorado Water Conservation Board says cloud seeding in southwestern Colorado is helping to squeeze more water out of passing snowstorms, using heaters that vaporize silver iodide to form artificial ice.

In southwest Colorado, workers light generators that look like large propane tanks, shooting flames into pans that send vaporized silver iodide up to the base of clouds. There, the silver iodide forms an artificial ice crystal that draws in more water, forming larger snowflakes. Then they fall to the ground.

“When there’s lots of liquid water coming through, then you have a storm to work. The seeding response is better. You get more bang for your buck,” said Joe Busto, a researcher with the Colorado Water Conservation Board. “It’s meant to add just a little bit more per storm.”

Researchers say a study in Wyoming conducted from 2005 to 2014 found cloud seeding can add 5 to 15 percent more precipitation.

Eric Hjermstad, co-owner and director of field operations for Western Weather Consultants, which does cloud seeding, said every bit of water helps the parched Southwest.

Hjermstad said seeding helps build snowpack to replenish aquifers and helps fill reservoirs such as Lake Powell for other Western states struggling to find water.

Regional water agencies and ski resorts paid $237,900 this season to help with the seeding, according to the Southwestern Water Conservation District. Western Weather operates about 36 generators from Pagosa Springs to Telluride.

The Southwest Basin Roundtable is providing $55,600 to hire a consultant to help select equipment and find the right areas to place it.