MAY 3, 1999 OKLAHOMA/KANSAS TORNADO OUTBREAKA total of 74 tornadoes touched down across the two states in less than 21 hours. At one point, there were as many as four tornadoes reported on the ground at the same time. The strongest tornado, rated a maximum F-5 on the Fujita Tornado Scale, tracked for nearly an hour and a half along a 38-mile path from Chickasha through south Oklahoma City and the suburbs of Bridge Creek, Newcastle, Moore, Midwest City and Del City.