 Data and observations began to accumulate that debunked Stormfury 's working hypothesis . Beginning with Hurricanes Anita and David , flights by Hurricane Hunter aircraft encountered events similar to what happened in " successfully " seeded storms . Anita itself had a weak example of a concentric eyewall cycle , and David a more dramatic one . In August 1980 , Hurricane Allen passed through the Atlantic , Caribbean , and Gulf of Mexico . It also underwent changes in the diameter of its eye and developed multiple eyewalls . All this was consistent with the behavior that would have been expected of Allen had it been seeded . Thus , what Stormfury was accomplishing by seeding was also happening on its own . 
