2011 Joplin tornado
The 2011 Joplin tornado was a catastrophic EF5-rated multiple-vortex tornado that struck Joplin, Missouri, late in the afternoon of Sunday, May 22, 2011. It was part of a larger late-May tornado outbreak and reached a maximum width of nearly during its path through the southern part of the city. This particular tornado was unusual in that it intensified in strength and grew larger in size at a very fast rate. The tornado tracked eastward across the city, and then continued eastward across Interstate 44 into rural portions of Jasper County and Newton County. It was the third tornado to strike Joplin since May 1971.
Tornadoes in the United States
On May 3, 1999, a storm produced a violent tornado in the vicinity of Oklahoma City and was a part of the 1999 Oklahoma tornado outbreak, which also brought many violent storms to the states of Kansas, Arkansas, and Tennessee. In total, the storm produced 66 tornadoes over four states. The strong F5 storm took place near the town of Bridge Creek, Oklahoma, located in Grady County. During the storm, a group of students in meteorology from the University of Oklahoma had chased the storm on a Doppler on Wheels (or DOW), which scans storms while attached to a car. Doppler on Wheels data from the nearby storm revealed winds of , which was over the wind speed in the F5 classification of that time. Though the wind speed was over the F5 maximum, the tornado was not named the first ever F6 storm, as there was no F6 classification. Other scientists reviewed the DOW data taken by the students, and concluded that the estimated wind speed may have been inaccurate, but still over . Also, the wind speed recorded was taken from over above ground level. The National Weather Service also did a damage check, and found that the damage was that of an average F5 tornado.