This is used for both precipitation augmentation and cloud dissipation. The basis for such modifications is artificial stimulation of the Bergeron-Findeisen process. Cloud seeding can only be undertaken when a cold cloud is already present and so serves as a means of precipitation augmentation, not’ rainmaking’ in an area with no naturally occurring chance of rain. Due to this restriction it is extremely difficult to demonstrate vigorously that a specific cloud seeding project has led to increase in rainfall. Nevertheless, the balance of evidence suggests that the technique is useful in areas where a small increase in precipitation can lead to significant economic gain.
Hence, for example, it is widely practiced in the somewhat marginal agricultural areas of the American Midwest and in South Africa. It is also used to augment winter snowfall in the American Rockies, helping to enhance the amount of water in that frozen reservoir, which will become available in subsequent growing season.
Attempts are being made to use cloud seeding techniques to modify the microstructure of clouds as an aid to hail suppression. If a large number of small hailstones can be produced to replace a small number of large ones, there is likely to be a decrease in the damage the hail causes. This technique has been experimented in the tea growing areas of Kericho without much success.
sharon kalunda answered the question on May 13, 2019 at 12:25