Frequently Asked Questions

Cloud Seeding, often called weather modification, is a scientific process that increases rainfall and snowpack, reduces hail damage, and dissipates fog. Suitable clouds are treated with precisely-timed dispersal of specific catalysts by aircraft or ground-based platforms, which accelerate the development of precipitation. 

Cloud Seeding improves a cloud's ability to produce precipitation by adding tiny particles, called ice nuclei (IN), with a crystalline structure which mimics that of ice, hastening freezing in cold clouds.

These nuclei help the cloud produce precipitation by acting on supercooled liquid water (SLW). In nature, cloud droplets remain in liquid form at temperatures well below 0°C. Natural ice nuclei often don’t result in ice formation until clouds cool to temperatures around -18°C. 

In thunderstorms, this cooling is accomplished by vertical growth into higher, colder atmosphere. The addition of artificial IN, typically silver-iodide (AgI) or other similarly-shaped crystals, can result in cloud ice production at temperatures as warm as -5°C. This gives the clouds a significant head start in precipitation development, and ultimately increases the precipitation production of the cloud. 

The visual results of Cloud Seeding - rain or snowfall - appear distinctly on radar within 20 minutes

No. The active ingredient in cold Cloud Seeding agents is Silver Iodide (AgI). Unlike ionic Silver, the Silver Iodide compound is very stable, essentially inert.

Iodine has been used in tablet form for decades by the Military and campers & hikers to purify creek or pond water, in the same way Chlorine purifies swimming pools and Fluorine purifies mains water. 

Numerous peer-reviewed scientific studies clearly demonstrate that no environmentally-harmful effects arise from Cloud Seeding with AgI, including in projects operated continuously over decades. 

No. Cloud Seeding should be utilised as a long-term water resource management tool. Although drought is sometimes the impetus for implementing a Cloud Seeding program, it is not generally advocated to stop drought. 

Longer-term, well-designed Cloud Seeding programs can soften the impact of drought, as increased precipitation results in higher reservoir and groundwater (soil moisture) levels before the drought, and faster recovery after.

Yes. Using sophistacted weather modelling software, Project Rainmaker is able to target and precisely treat particular weather systems early in their development, arresting the formation of large hail stones which cause billions of dollars of damage ($7.9Bn from 2014-20) to crops and property. 

Successful hail suppression programs are being conducted in North America, Europe, and Asia, resulting in up to 100% prevention of hail damage.

No. Cloud Seeding changes the precipitation efficiency of individual clouds or groups of clouds. Changes to large-scale weather patterns are determined by much greater forces such as global atmospheric circulation patterns and ocean temperatures. 

No, on the contrary. It is a common misconception that Cloud Seeding robs one area of rainfall or robs “Peter” to water “Paul”. This arises from a lack of understanding of cloud-water budgets and what ultimately happens to precipitation. In a cloudless atmosphere there is often a large amount of water vapor, it’s just invisible because it is still vapor.

Clouds develop only when condensation occurs, and cloud droplets form. These droplets are far too small to precipitate; they must grow by either colliding with other droplets, or when ice forms. The former process requires about 1,000,000 cloud droplets to gather to produce a single raindrop. The latter requires the cloud to get cold enough to form ice naturally.

When a thunderstorm develops, it does not contain all the water vapor in the atmosphere, just a portion of what exists in the vicinity of the storm. If the storm is very large and vigorous, perhaps as much as 20% of the water vapor in its immediate area condenses to form cloud. In such a case, our storm has captured some of the water vapor, but 80% remains in the atmosphere.

Large fractions of summertime rains are typically consumed by vegetation and quickly transpired back into the atmosphere. Another fraction simply evaporates from the surface. Both “recharge” the atmosphere. 

When water from recent rains are transpired by plants and evaporate back into the atmosphere, the humidity downwind is increased, improving the moisture supply for future clouds. 

If you need rain, is it better to have moist air moving your way, or drier air? Cloud Seeding, by increasing rainfall, amplifies the positive-feedback loop that results from precipitation.  

The success of cloud seeding programs can be measured by;

1) the comparison of precipitation gauge data on the ground with forecasted values.

2) analysis of historical rainfall data to compare rainfall or snowfall during seeded and non-seeded periods.

3) the comparison of seeded seasons with other non-seeded seasons in the same location.

4) observing distinct Cloud Seeding patterns appear in real time on weather radar.

5) peer reviewed (independently verified) project case studies.

The latest information from the World Meteorological Organization Weather Modification Group states 52 countries worldwide participate in cloud seeding programs. Project objectives include rainfall and snowpack enhancement, hail suppression, and fog dispersal.