Portuguese 
The hail cannon used by farmers in São Joaquim generates supersonic waves through controlled explosions of acetylene gas, reaches over 10,000 meters in height, and aims to reduce hail before it falls; according to the responsible company, effective protection extends to 500 meters around the equipment.
Farmers in São Joaquim, located in the Santa Catarina Highlands, activated a private hail cannon during the instability episodes that have brought ice pellets back to the region. The sonic equipment uses controlled explosions of acetylene gas to generate waves directed toward the atmosphere in an attempt to weaken the hail before it reaches crops.
The system was reported to be operational during the last days of August 2026, a time when cities in Santa Catarina experienced storms with hail. In São Joaquim, ice pellets fell on Monday, August 31, as farmers turned to private equipment to try to mitigate losses, particularly in agricultural areas.
Hail cannon fires a new wave every seven seconds
The model used by some farmers in São Joaquim is known as a sonic cannon. Its operation starts with controlled explosions of acetylene gas, which generate supersonic waves directed vertically into the atmosphere.
-
Antarctica Developed a Continental-Scale Ice Sheet 34 Million Years Ago, When the Earth Was About 5°C Warmer Than Today
-
China Develops a Laser Data Highway Connecting Earth and the Moon Over 400,000 Kilometers, Achieving 100 Mbps and Demonstrating 8K Image Transmission in Just 12 Seconds with New Space Technology
-
First Foldable iPhone Expected to Launch on September 9 Alongside iPhone 18, Camera Innovations, and New Leadership Phase at Apple
-
NASA Identifies Exoplanet 23 Times More Massive Than Earth, 53 Light-Years Away, with a 36-Day Orbit in a System Also Hosting the First Earth-Size Planet Found by TESS
According to information disclosed about the equipment, the hail cannon generates these waves at intervals of approximately seven seconds. The energy produced travels to the upper layers of the atmosphere and can reach altitudes over 10,000 meters.
Waves aim to hit the ice while it is still within the cloud
The device does not wait for the hail to reach the ground. The system tries to intervene while the ice pellets are still forming or remain within storm clouds.
The explanation provided for the process is that the waves generated by the hail cannon create successive layers of energy that would target the hail cell and help weaken its structure. The goal is for the ice to reach the ground in smaller sizes or to melt during its fall.
Effective protection area is estimated at a radius of 500 meters
According to Emerson Carneiro, director of Try Brazil, the company responsible for the equipment mentioned by the source, the system provides an effective protection area of approximately 500 meters in radius around the point where it is installed.
The company also states that the hail cannon can reach areas beyond that distance, although with decreased efficiency. The 98% rate cited for the main area is also an estimate provided by the system’s supplier and not an independent measurement presented in the report.
Each shot produces a wave that can last about 29 seconds
Although the interval between shots is seven seconds, the energy of each wave lasts longer. According to the technical information presented, each wave can last approximately 29 seconds.
The system is programmed to provide protection for average periods of about 30 minutes. This means that operation involves a continuous sequence of shots during the passage of weather cells considered capable of producing hail.
Meteorological monitoring helps decide when to turn on the equipment
Activation does not need to occur only when the first hailstones begin to fall. The hail cannon can be activated remotely, linked to meteorological monitoring conducted 24 hours a day.
There is also the possibility of manual activation. The idea is to start the equipment before or during the approach of a storm with the potential to produce hail, creating a sequence of waves while the cell is still over the protected area.
Sound reaches about 50 decibels at 500 meters
The explosions that produce the waves also generate noise noticeable nearby. According to data presented by the company, the sound intensity measured at approximately 500 meters is close to 50 decibels.
The sound can be heard at greater distances. Depending on the terrain, atmospheric conditions, and the observer’s position, the shots may be perceived at about 1 kilometer from the equipment.
Producers turned to private equipment in São Joaquim
The cannons that recently came into operation in the municipality do not belong to the public system. According to the city hall, the equipment activated in the past few days was purchased and installed by farmers.
This is happening while municipalities in the Santa Catarina mountains progress in implementing public structures to combat hail. In São Joaquim, however, the public system mentioned by the city hall was still not operational when the private equipment was recorded in operation.
Hail represents a particularly significant threat to orchards
The Santa Catarina mountains regularly experience storms capable of producing hail. For farmers, the issue goes beyond the impact on roofs and vehicles, as ice stones can directly hit developing crops.
Among the vulnerable productions are fruits, especially apples, strongly associated with the economic activity of São Joaquim and other mountain municipalities. A sufficiently intense storm can damage fruits, leaves, and branches in a matter of minutes, which is why preventive systems attract the interest of producers.
Sonic cannon is not the only hail prevention system used in Santa Catarina
Despite the visual and auditory impact of the cannon, there is another technology widely used in the state: cloud seeding with silver iodide. Both systems aim to reduce damage caused by hail but operate in different ways.
While the sonic hail cannon works with waves produced by controlled explosions of acetylene gas, the silver iodide method introduces particles into the atmosphere to increase the number of available freezing nuclei within the clouds.
Silver iodide attempts to form many smaller stones
In cloud seeding, the goal is not to completely prevent ice formation. Silver iodide aims to multiply the points where water can freeze, distributing the formation of ice among a larger number of particles.
According to data presented in the source, the number of freezing nuclei can increase from just 1 or 2 to around 100 to 120 per cubic meter. Instead of a few stones growing large, the expectation is to favor the formation of smaller hailstones, which have a greater chance of melting during their descent or hitting crops with less force.
Generators with silver iodide cover a much larger area
The range also distinguishes the technologies. According to João Luiz Walter Rolim, a meteorologist and director of AGF Antigranizo Fraiburgo, each silver iodide generator can cover an approximate radius of 5 kilometers.
These devices release about 8.6 grams of silver iodide per hour, according to the specialist’s data. The range is therefore significantly higher than the 500 meters indicated as the area of greatest efficiency for the sonic system mentioned in São Joaquim.
Hail is formed when water is carried to the cold regions of the cloud
To understand the purpose of these devices, it is necessary to observe how the phenomenon forms. Hail is an ice precipitation produced when upward currents transport water droplets to very cold areas within clouds.
The water freezes and may continue circulating within the storm, accumulating new layers of ice. The more intense the vertical movements capable of supporting these particles, the larger the stone can become before falling.
Technology aims to reduce impact, not eliminate storms
Neither the sonic system nor silver iodide is presented as mechanisms capable of preventing storms from occurring. The objective is to specifically act on hail to try to decrease its size and, consequently, the damage caused to the ground.
In the case of the hail cannon, the bet is on the supersonic waves fired repeatedly toward the storm cell. In the seeding system, the strategy lies in altering the number of nuclei available for ice formation.
Producers rely on firings every seven seconds to protect crops
The scene of a device producing successive explosions in the mountains may seem unusual, but it reveals the scale of the challenge faced by farmers when a hailstorm approaches. In São Joaquim, private producers have already started implementing the system while the public structure in the municipality has not yet become operational.
