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Wyoming cloud seeding activities shared

by Wyoming Livestock Roundup

Cheyenne – The Wyoming Water Development Office (WWDO) started cloud seeding in the early 2000s. WWDO Project Manager Julie Gondzar elaborates on her passion for cloud seeding and discusses Wyoming’s current operational projects over the Wind River Mountains as well as the Medicine Bow and Sierra Madre mountain ranges.   

Process of seeding clouds 

Cloud seeding is conducted during the winter season, generally Nov. 15 through April 15, over mountain ranges to promote a cloud’s natural precipitation process. As ice crystals grow in a cloud, the crystals turn into snowflakes and fall to the ground, explains Gondzar.  

“Cloud seeding is essentially cloud physics – initiating a process that already has a high potential,” says Gondzar.  

Silver iodide is a natural compound used during the seeding process and is similar to the structure of naturally forming ice crystals.  

“When silver iodide is distributed into the atmosphere it aerosolizes – you can’t see it,” says Gonzar. “And, you only need a few grams to start the ice crystallization process in the cloud.” 

The process of seeding clouds can be done by either aircraft or on ground-based operations, she continues. It is estimated that the production of snow can occur within 15 to 30 minutes from the start of seeding. The state of Wyoming has two cloud seeding operations – a ground-based and an aerial operation. 

Wyoming cloud seeding operations  

The Wind River Mountains Cloud Seeding project is a ground-based operation and is the longest operational cloud seeding project. Cloud seeding is conducted by using 10 remote controlled generators. 

“Ground-based generators are similar in appearance to a 10- to 15-foot weather station,” she says. “The silver iodide solution is in a liquid tank and is aerosolized out the top.”  

The wind direction and updraft of the wind moves the silver iodide over the mountain ranges.   

Aerial seeding takes place over the North Platte and Little Snake basins with the Medicine Bow and Sierra Madre mountain ranges. Aerial cloud seeding started in the state of Wyoming in the winter of 2018-19.  

Cloud seeding by aircraft is cost-effective, mentions Gondzar.  

“In an aircraft, the silver iodide is put into a flare,” she says. “There are 36 flares on the left wing and 36 on the right wing.” 

The flares take about five minutes to burn and burn one at a time through an icing layer of the atmosphere. The plane also has several 100 ejectable flares on the belly housed in a cardboard casing, which are ignited and dropped, she continues. 

There are two kinds of flares used in cloud seeding. This allows the aircraft to seed clouds within or above an icing layer, depending on what is safer for the aircraft, Gondzar explains.   

Aerial seeding takes place Nov. 1 through April 15 with a King Air aircraft based at the Cheyenne Regional Airport.  

“There are very specific meteorological and atmospheric parameters to be met before cloud seeding can happen,” explains Gondzar. “Often times, seeding will take place ahead of an impending snowstorm, or within clouds that have a high potential for snowfall and contain lots of super-cooled liquid water.” 

Certain temperatures and water content need to be found inside the cloud before cloud seeding can take place.  

Advantages and misconceptions 

Cloud seeding is an effective way to increase snowpack conditions over time, above what nature can produce. 

“Cloud seeding initiates the snow fall process sooner than when it may have happened naturally,” Gondzar explains. “Increasing the crystals in a snow packed cloud is a small incremental change that can be done seasonally, and when consistent – this is the key to successful cloud seeding.” 

Consistency is important, even through dry years, she says.  

“Cloud seeding is technology that Wyoming can constantly use and works really well when we have a good snow season,” Gondzar adds.  

It’s important for producers to realize this process is not going to break a drought year, create clouds, move clouds or change cloudiness, winds or temperature.  

Gondzar is working to transition the terminology of “weather modification” to cloud seeding because it’s a very common misconception that cloud seeding is changing and controlling the weather, and she explains this is simply not the case.  

She notes one thing people need to understand is cloud seeding occurs on a very small scale. The target areas are very small and limited to high elevation mountain tops, where water can be stored in the form of snow.   

“Cloud seeding cannot deplete an area of moisture downstream,” she explains. “The percentage of water that is used in a cloud is so small, but it’s enough to get a little bit of extra snow and that’s gold here.”  

Additional operations  

Wyoming is one of seven states taking part in a formal cost-sharing agreement between the Upper and Lower Basin parties to continue the use of cloud seeding efforts. With severe drought conditions, this agreement is vital in keeping the program funded, Gondzar explains. The partnership provides flexibility and occasional additional funding to expand state cloud seeding programs, in addition to collective contributions to reach $1,500,000 in a single water year.  

Colorado’s Never Summer Mountain Range is an additional program to Wyoming’s aerial project paid for and sponsored by Colorado’s Jackson County Water Conservancy District in Walden, Colo.  

Additional cloud seeding programs take place in Colorado, Idaho, North Dakota, Utah and Nevada.  

“WWDO also has a small partnership with the Colorado Water Conservation District to extend the seeding into one of their mountain ranges,” says Gondzar. “It of course benefits the state of Wyoming with it being a part of the North Platte River Basin.” 

Looking to the future  

WWDO is in the process of preparing to present at the next legislative session to ask for funds to complete an assessment of the program.  

“It’s not a matter of if it works,” she says, “It’s a matter of how well.” 

Gondzar is confident in the continuation of the program and shares cloud seeding is making a difference. Her future goals include adding a second plane to the program.  

Brittany Gunn is the editor of the Wyoming Livestock Roundup. Send comments on this article to  

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