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-22- An examination of the "watch" information in conjunction with seeding opportunity days indicates that for the 7-year period, there averaged only 3.1 June wet days without any total area watch. There would by 7.7 potential operational days per month with all watches (DDC area) suspension cri- terion in effect. The tornado watches (DDC area) criterion would allow 11.3 potential operational days. The results of the preceding section have demonstrated that the severe weather watch is not well suited for suspen- sion criteria. The large number of severe thunderstorm and tornado watches remove many potential seeding opportunities, thereby placing the. effectiveness of commercial seeding pro- grams in jeopardy and increasing the length of scientific seeding experiments. Because of the high failure rate for the tornado watch, operations conducted on days for which no watch has been issued leave program operators open to the charge that seeding increased the potential for tornadoes on days that severe weather was not expected. But is there a better data source for suspension criteria than the severe weather watch? A seeding project may provide its own severe weather data. This approach is attractive be- cause project forecasters can concentrate their efforts toward weather events over the operational area. However, the NSSFC has the benefit of years of forecast experience, and the per- formance of the tornado watch should be credited mostly to the complexity of the tornado forecast problem. Perhaps suspension criteria developed from severe weather warnings issued by local Weather Service offices would be use- ful. These warnings are usually issued when severe weather has already been reported by the public or when storms approach severe limits as determined by radar. If seeding operations are being conducted when the warnings are given, even though operations are terminated, the continuing dynamical and micro- physical interactions of seeding material with nearby storms could lead to implications of property damage liability. ?