Andover, Kansas Tornado Outbreak

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Andover, Kansas Tornado Outbreak

Date of tornado outbreak:	April 26, 1991
Duration1:	19 hours
Maximum rated tornado2:	F5 tornado
Tornadoes caused:	58 confirmed
Damages:	$250+ million (1991 USD) [1]
Fatalities:	24 [2]
Areas affected:	Oklahoma, Kansas
1Time from first tornado to last tornado 2Most severe tornado damage; see Fujita Scale

The Andover, Kansas Tornado is among the most notorious tornadoes of the 20th century. It was the most significant tornado in nearly 70 years to hit Kansas, Oklahoma, and surrounding areas, on the date April 26, 1991. It was the only F5 tornado of 1991 and the 16th F5 tornado to hit in Kansas state history. Seventeen people were killed and 225 were injured. This tornado was caught on tape by dozens of people, both professionally and on home video. One such recording depicts the twister, dark grey and slender, approaching a Kansas air force base. It tears through a parking lot as people in a nearby building watch and record. The tornado visibly intensifies in the short time it spends at the base, exitting as a large, multiple-vortex storm. A 3 billion-dollar+ line of B-1 Lancer strategic bombers and KC-135 Stratotankers were narrowly missed. Had the tornado destroyed the aircraft it would surely have been considered the costliest tornado in history. The Weather Channel later produced a video documentary of the Andover outbreak titled "The Enemy Wind".

Contents 1 Forecast 2 The Andover Tornado 3 The El Dorado Lake Tornado 4 The Red Rock Tornado 5 Aftermath 6 See also 7 Resources

[edit] Forecast

On April 25, The Storm Prediction Center predicted a "high risk" of severe weather for the following day. In fact, they also issued issued a Public Severe Weather Outlook stating that an "extremely dangerous weather situation" was forecast for much of the middle United States. A strong storm system was due to move through the area the next afternoon & evening [3].

Confirmed Total	Confirmed F0	Confirmed F1	Confirmed F2	Confirmed F3	Confirmed F4	Confirmed F5
58	12	14	19	8	4	1

(based on NOAA Storm Data)

F#	Location	County	Time (UTC)	Path length	Damage
Kansas
F2	Montgomery	Montgomery	0945	6 miles (9.7 km)
F2	Washington	Washington	1425	4 miles (6.5 km)
F0	Chase	Chase	1445	1 mile (1.6 km)
F3	Washington	Washington	1450	25 miles (40.5 km)
F0	Morris, Wabaunsee	Morris, Wabaunsee	1510	13 miles (21.1 km)
F2	Wabaunsee, Shawnee, Jackson	Wabaunsee, Shawnee, Jackson	1535	44 miles (71.3 km)
F0	Harper, Sumner	Harper, Sumner	1620	18 miles (29.2 km)
F0	Sumner	Sumner	1630	4 miles (6.5 km)
F1	Sedgwick	Sedgwick	1647	2 miles (3.2 km)
F5	From Haysville to El Dorado Lake	Sedgwick, Butler	1657	46 miles (74.6 km)	17 deaths - Began as a narrow F2-F3 tornado in Haysville; However, it rapidly widened and intensified as it moved through McConnell Air Force Base. There was immense damage in McConnell, and many well constructed homes were swept off their foundations in Andover. Golden Spur Mobile Home Park demolished with numerous injuries and fatalities. Storm was well documented through video, photography, and eyewitness accounts - see section on this
F1	Sedgwick, Harvey	Sedgwick, Harvey	1710	2 miles (3.2 km)
F4	W of Arkansas City to Cambridge	Cowley	1730	25 miles (40.5 km)	1 death - Tornado passed Arkansas City to the west, and then moved between the communities of Strother Field and Hackney. Many suburban homes were completely destroyed, and one woman was killed in her home.
F0	Wabaunsee	Wabaunsee	1735	9 miles (14.6 km)
F2	Butler, Chase	Butler, Chase	1810	25 miles (40.5 km)	Tornado touched down near El Dorado Lake. It was captured on video by several reporters who sought shelter under a highway overpass - see section on this
F3	Howard to Severy	Elk, Greenwood	1826	14 miles (22.7 km)	1 death - Spawn from the same storm that produced the Strother/Hackney F4 tornado. Six miles north of Howard the tornado leveled a mobile home killing the occupant.
F0	Chase	Chase	1840	1 mile (1.6 km)
F0	Sedgwick	Sedgwick	1933	1 mile (1.6 km)
F3	Greenwood, Woodson	Greenwood, Woodson	1935	15 miles (24.3 km)
F1	Shawnee, Jefferson	Shawnee, Jefferson	1945	11 miles (17.8 km)
F2	Jefferson, Atchison	Jefferson, Atchison	2000	25 miles (40.5 km)
F0	Montgomery	Montgomery	2120	1 miles (1.6 km)
Oklahoma
F2	Kay	Kay	0545	1 mile (1.6 km)
F3	Garfield	Garfield	1700	6 miles (9.7 km)
F0	Garfield	Garfield	1715	unknown
F4	Garfield, Noble, Osage	Garfield, Noble, Osage	1730	66 miles (107.0 km)	Longest tracked, and probably most violent tornado of the outbreak. The monsterous storm was followed and documented for most of its 66 mile path by numerous storm chasers. Fortunately, it spent most of its life in open country and only affected a handful of man-made structures causing minimal injuries/damage. The highest rating that could be given was F4 based on the small amount of damage done. Had this tornado tracked through a populated area, the destruction/loss of life would have been devastating - see section on this
F3	Payne	Payne	1838	7 miles (11.3 km)
F4	Westport area	Pawnee, Osage	1910	32 miles (51.9 km)	1 death - Very large and dangerous tornado moved through the Westport area leveling several well constructed homes/buildings and causing 24 injuries on top of one fatality (a man was killed in his car on the Cimarron Turnpike).
F1	Osage	Osage	1927	unknown
F2	Washington	Washington	2005	6 miles (9.7 km)	1 death - Fatality probably occurred the storm struck a mobile home or automobile.
F4	Ookogah area	Rogers	2045	4 miles (6.5 km)	Though short-lived, this large and violent tornado destroyed several homes and severely damaged a high school in the Oologah area before abruptly dissipating. 22 people were injured; however, there were no fatalities. On top of the destruction this tornado caused, a downburst that followed the storm caused further damage.
F1	Rogers	Rogers	2110	2 miles (3.2 km)
Nebraska
F1	Fillmore	Fillmore	1440	1 mile (1.6 km)
F2	Gage	Gage	1600	4 miles (6.5 km)
F3	Otoe	Otoe	1615	14 miles (22.7 km)
F0	Pierce	Pierce	1715	unknown
Texas
F2	Cherokee	Cherokee	1800	unknown
F3	Cherokee	Cherokee	1811	3 miles (4.9 km)
F2	Smith	Smith	1840	1 miles (1.6 km)
F2	Rusk	Rusk	1844	2 miles (3.2 km)
F2	Rusk	Rusk	1900	unknown
F1	Rusk	Rusk	1922	unknown
F2	Red River	Red River	2100	unknown
F1	Red River	Red River	2119	unknown
F2	Red River	Red River	2130	unknown
F1	Red River	Red River	0105	unknown
Iowa
F1	Shelby	Shelby	1844	2 miles (3.2 km)
F3	Crawford	Crawford	1900	2 miles (3.2 km)
F3	Sac	Sac	1913	6 miles (9.7 km)
F2	Dickenson	Dickenson	2000	18 miles (29.3 km)
F2	Wayne	Wayne	2210	9 miles (14.6 km)
F2	Wayne	Wayne	2210	15 miles (24.3 km)
F2	Iowa	Iowa	0055	5 miles (8.1 km)
F1	Iowa	Iowa	0109	2 miles (3.2 km)
Missouri
F1	Andrew	Andrew	2115	2 miles (3.2 km)
F0	Newton	Newton	2239	3 miles (4.9 km)
F1	Andrew	Andrew	2257	2 miles (3.2 km)
F0	Jasper	Jasper	2305	unknown
Sources: NOAA Storm Data

[edit] The Andover Tornado

Outbreak death toll

State	Total	County	County total
Kansas	19	Butler	13
		Cowley	1
		Elk	1
		Sedgwick	4
Oklahoma	2	Pawnee	1
		Washington	1
Totals	21
All deaths were tornado-related

The tornado that produced the most 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 as it crossed the Kansas Turnpike for the first time and headed toward McConnell Air Force Base.

Many people had advanced warning before the tornado struck McConnell Air Force Base. The tornado struck the base school & housing at F2-F3 strength. It caused $62 million in damage on base, narrowly missing a multi-million 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 feet wide and was producing F5 damage on the Fujita scale. It continued to move Northeast toward the Golden Spur Mobile Home Park in Andover, KS; 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, KS. 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 P.M. 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.

[edit] The El Dorado Lake Tornado

The new tornado moved Northeast toward Cassoday, KS. A news team from KSNW-TV in Wichita was returning to the station along the Kansas Turnpike from a story unrelated to the tornado. The reporters soon encountered a tornado, and decided to try to shoot video of the storm. However, the tornado veered and began following a path along the highway at a speed faster than they could drive. They reached an overpass where several people had already abandoned their cars. The cameraman advised the other people that they should all get into the very upper part of the overpass, thinking that this would shield them from the wind. The cameraman recorded the entire chain of events as the tornado passed nearby. The overpass itself did not receive a direct hit from the tornado, but it appeared to on camera. It lasted approximately 20 seconds. The tornado then continued northeast and dissipated at about 7:30 p.m., just Northeast of the Cassoday Interchange of the Kansas Turnpike. All the cars parked under the underpass had their windows blown out. Other cars and big rigs on the turnpike (actually hit by the tornado) rolled multiple times and were tossed all over the road.

[edit] The Red Rock Tornado

South of Wichita, in Garfield County, Oklahoma, tornado chasers (including Warren Faidley, Gene Moore, and many other big-name chasers) observed the touchdown of what would be the longest tracked tornado of the outbreak. Initially, the storm was narrow and produced up to F3 damage to the south of Billings. A few oil tanks were toppled and power poles were knocked down. As the funnel crossed into Noble County, video and photographic evidence suggests dramatic widening and strengthening. The damage path across northern Noble County appeared to be between 3/4 and 1 mile in diameter. Trees were debarked and pavement was scoured off roads. The tornado encountered few man-made structures along its path. At least one home was completely demolished leaving no walls standing (indicating F4 damage). At one point a University of Oklahoma chase team used a portable dopplar radar to measure a windspeed of 257-268 mph in the funnel (near the F5 threshold). At the time, this was the fastest wind speed ever measured on the face of the earth (it has now been surpassed by the Moore, Oklahoma City tornado, which produced a 1/4 mile gust of 301 mph[4] on May 3, 1999). As the tornado passed through Noble County and into Osage County, two farms were completely destroyed and several additional oil rigs were toppled. The tornado lifted in central Osage County, after having traveled for 66 miles. It is likely that this was the most violent tornado of the outbreak (exhibited dramatic multiple vorticies and motion); however, it did not encounter many man-made structures making it difficult for storm survey teams to rate it. It was given an F4 rating, which was probably the best they could have done, given the data available in the situation.

[edit] Aftermath

In addition to the millions of dollars of damage, 225 injuries and seventeen deaths, the tornado also contributed to the commonly held (albeit false) belief regarding tornado safety. Due to the popularity of the news team's video, in which they are depicted surviving by using an overpass for shelter, overpasses are now frequently jammed with people seeking shelter during tornado activity. Such was the case in many areas during the 1999 Oklahoma Tornado Outbreak, in which some people actually left the safety of their homes when the tornado warning was issued to take shelter under overpasses. One tornado hit three underpasses and killed people at each one.

An overpass is an extremely dangerous spot to be in a tornado, especially if it does not have the open girder design like that in the video. That bridge design is very rare; the vast majority of underpasses are mere open slabs, offering no protection from wind and debris. Using these underpasses as protection does little more than raise people above ground level, exposing them to higher winds and more debris. Additionally, the windspeed may be increased by the wind tunnel effect. Another danger is the sheer number of people now congregating at underpasses blocks traffic, which has hindered emergency responders. Moreover, it presents the danger that an intense tornado will hit people taking shelter as well as bystanders stuck in traffic, who are massed in a vulnerable location incurring the possibility of a significant death toll. NWS Presentation on Deaths Due to Use of Underpasses as Shelters

[edit] See also

• List of tornadoes and tornado outbreaks

[edit] Resources

• Gene Moore's April 26, 1991 Chase Account
• The Red Rock Tornado
• NOAA Storm Data
• PDS Tornado Watch #183 - NSSFC
• Website on Andover tornado
• ↑ Site dispeling tornado "myths," with a mention of overpasses
• Video of this tornado