F1 tornado in Pawnee County, Oklahoma

A tornado briefly touched down in the southwest part of the city of Pawnee at 738 PM CDT near 6th Street and Ash. The tornado travelled northeast for 0.4 miles and had a width of 125 yards. Many trees were downed or snapped along the path with about fifty homes receiving minor roof, window, and porch damage. One mobile home was destroyed. Widespread wind damage also occurred in Pawnee due to strong winds in the vicinity of the tornado known as a "rear flank downdraft". The roof at the high school auditorium was blown off by the nearby winds. Damage from the tornado and the winds combined were nearly $2 million. (The official damage estimate in this entry does not include damages caused by the nearby winds.)Most of the tornado damage was F0. However, the tornado was rated F1 based on an estimate of the most intense winds reaching speeds near 85 mph. The tornado lifted before reaching US Hwy 64. However, an isolated home downstream of the tornado path and 2 miles from downtown Pawnee received F1 damage. The Pawnee mesonet site, located 3 miles ENE of Pawnee and 0.4 miles north of the house, measured wind gusts as high as 80 mph. (See the separate Thunderstorm Wind entry for more information on the mesonet observations.) The open prairie, the associated lack of tracers (wind-blown objects) near the mesonet site, and the isolated nature of the home make it impossible to determine if tornadic damage occurred at/near these locations. However, the tornado damage in Pawnee, the F1 damaged home, and the mesonet site are all aligned along the storm's motion.

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.