April 26, 1991: The Andover Tornado
Damage from the Andover tornadoGround zero for the outbreak was this tornado, because it reached a powerful F-5 status, and caused the most damage and deaths of the outbreak. To people of the area, and to storm chasers, it is simply known as "the Andover tornado". This tornado is one of the most filmed of all time, because by 1991, video camcorders were very popular and easily obtainable by the general public. So the Andover tornado was filmed from many different angles and during a large portion of its life, and the incredible number of videos that were released shocked the nation. All of the video, plus the tornado's F-5 power and the extensive damage it caused, has made this tornado very highly studied and notorious.
It first produced extensive damage formed south of Clearwater, Kansas. It fluctuated between F2 and F3 intensity as it crossed I-35 and moved across the city of Haysville. Widespread damage was reported in Haysville, but there were no fatalities. On the east side of Haysville, the tornado became a solid F3 in strength and expanded to around 300 feet wide as it crossed I-35 (the Kansas Turnpike) and headed toward McConnell Air Force Base.
Many people had advance warning before the tornado struck McConnell Air Force Base. The tornado struck the base school, hospital and housing at F2–F3 strength. It caused $62 million in damage on the base, narrowly missing a multi-billion dollar line of B-1 bombers. The damage path widened as the tornado intensified to F4 strength just east-northeast of the base.
By 6:35 p.m., the tornado had expanded to just over 600 yards wide and was producing F5 damage on the Fujita scale. It continued to move northeast toward the Golden Spur Mobile Home Park in Andover, Kansas; as it passed through, it obliterated the park and caused thirteen deaths. The tornado then veered north, missing Girl Scout Camp Seikooc, where summer camp training was being conducted as well as a troop campout.
The tornado then moved on to the northeast, passing just south of Towanda. Most of the damage in this area was rated at F2–F3 intensity, though these numbers may be skewed: the rural area's lack of significant structures makes it difficult to accurately gauge the amount of damage. The tornado continued northeast and reached El Dorado Lake just before 7 pm (CST). Video taken by local storm chasers shows that the tornado crossed over the lake and revealed a multiple vortex structure. Just after crossing over the lake to the northeast, the original circulations dissipated and a new, much weaker tornado formed. The Andover tornado had traveled for nearly 46 miles, and was on the ground for over an hour.
This was the last F5 tornado that was recorded in Kansas under the old Fujita scale rating system. The next tornado of that scale, an EF5, was reported 16 years later on May 4, 2007 in Greensburg in Kansas about 120 miles west of the path of the 1991 tornado. Since February 1, 2007, the National Weather Service uses the Enhanced Fujita Scale.
http://en.wikipedia.org/wiki/1991_An...ndover_tornado