F1 tornado in Okmulgee County, Oklahoma

A seasoned storm chaser on an aerial survey of the area reported a one-mile damage track through a forested area in the Okmulgee Wildlife Management Area just east of Nuyaka. The degree of tree damage suggested the tornado was F1 intensity. Damage in this unpopulated area consisted of numerous trees blown over.

Summary of tornado/severe events for October 4 PM - October 5 1998:Oklahoma's worst-ever October tornado outbreak took place on the evening of October 4. At least 22 tornadoes occurred throughout Oklahoma, of which seven were in northeast Oklahoma. This outbreak of severe weather resulted as a powerful upper level storm system moved across the central plains and surface low pressure developed over southwest Oklahoma. Warm humid air quickly invaded the area on the morning of October 4 and then collided with a cold front moving southward by evening. The threat from these storms ran the full range of possibilities from destructive tornadoes to damaging winds to very large hail up to the size of baseballs.Numerous storms occurred on the evening of October 4, mainly north of Interstate 40. The two most significant storms both moved eastward out of central Oklahoma. One produced an F1 tornado that passed through Pawnee. The other produced a 27-mile track F2 tornado that started in Okfuskee County and ended in Okmulgee County. This second storm later went on to produce considerable hail and wind damage in the city of Okmulgee. Many other thunderstorms developed during the evening in central Oklahoma, fanned by upper level winds in excess of 100 knots. These storms moved into northeast Oklahoma, causing additional severe weather late in the evening that gradually spread eastward to the Arkansas state line. After midnight, the storms congealed and became a slow-moving line of thunderstorms that sat over nearly the same area of northeast Oklahoma through the overnight hours. The severe threat gradually diminished through the night, and flooding became the main problem. For more information on the flooding, see the separate event entry for the flooding. By late on the afternoon of October 5, the slow-moving line had moved into southeast Oklahoma and flared up during the heat of the afternoon, causing a few additional severe weather reports in the form of strong winds.