~ TECHNICAL NOTES ~ CORRESPONDENCE ~

during winter months when evapotranspiration rates are lowest and cloud-seeding equipment is not normally used. Background During an experimental cloud-seeding program in the 1980’s, rain-gauge analysis from Big Spring to San Angelo, Texas indicated that cloud seed-ing could effectively, efficiently, and economical-ly increase precipitation (Griffith, 1990). Based on these encouraging results, in 1996, eight west Texas counties formed the West Texas Weather Modification Association to develop a rain-en-hancement program to augment crop irrigation and suppress hail damage. The performance of this program has been assessed to ascertain its success in meeting its objectives and to deter-mine whether the program has been effective and economical. Based on this assessment, it became 1