Operational projects established to conduct seeding in order to influence hail formation or rain production from cumulus clouds have gone through progressive change. Techniques for direct injection of the nuclei into the interior cloud updrafts have been developed. In the USSR, artillery shells and rockets have been used to deliver warheads containing active cloud nuclei directly into the cloud updraft. Weather radar measurements are essential to the further conduct of the cloud-seeding procedures. Quantitative radar measurements are used to identify the exact regions where cloud seeding would be required. Of the various types of weather modification projects, the two most likely to achieve large-scale utilization are hail suppression and rain augmentation from cumulus clouds. The increasing demand for food and water highlights the perceived economic gain that can be achieved by application of weather modification techniques.