CLOUD SEEDING: KEEPING OUR FINGERS CROSSED

Supporters of cloud seeding to augment precipitation speak of the staaes of weather modification from an art to a science. Critics suq-gest that cloud seeding remains more of an art than a science, and that claims of successful precipitation augmentation lack scientific documen tation. Most recently, the Committee on Weather Modification, Irriga tion and drainage Division of the American Society of Civil Engineers (ASCE), prepared guidelines for "water resource managers who might be come involved in the decision-makinq Drocess for implementing a weather modification project. " The ouidelines suggest that cloud seeding to augment precioitation is an accomplished fact. There are no references to the unanswered Questions that have been raised in cloud seeding experiments such as indications of negative downwind effects. The water resource manager could be handicapped in making his decision without an adequate background on weather modification experiments. This paper is sugqested as a supplement to the guideline prepared by the Committee on Weather Modification. The unwary water resource manager should have access to, or be aware of, the uncertainties that remain in cloud seed ing. At the very least, he should know that there is a considerable bibliography available that suggests cloud seeding to augment precipita tion is not an accomplished fact