Tornado myths are incorrect beliefs about tornadoes, which can be attributed to many factors, including stories and news reports told by people unfamiliar with tornadoes, sensationalism by news media, and the presentation of incorrect information in popular entertainment. Common myths cover various aspects of the tornado, and include ideas about tornado safety, the minimization of tornado damage, and false assumptions about the size, shape, power, and path of the tornado itself.
Some people incorrectly believe that opening windows ahead of a tornado will reduce the damage from the storm. Some people also believe that escaping in a vehicle is the safest method of avoiding a tornado, but this could increase the danger in some situations. Other myths are that tornadoes can skip houses, always travel in a predictable direction, always extend visibly from the ground to the cloud, and increase in intensity with increasing width. Finally, some people believe that tornadoes occur only in North America, do not occur in winter, and that some areas are protected from tornadoes by rivers, mountains, valleys, tall buildings or other geographical or man-made features; the truth is that tornadoes can occur almost anywhere at any time if the conditions are right. Some geographic areas are simply more prone to these conditions than others.
Some tornado myths are remaining bits of folklore that are passed down by word of mouth. The idea that the southwest corner of a structure is the safest place in a tornado was first published in the 1800s and persisted until the 1990s despite being thoroughly debunked in the 1960s and 1970s. One notable instance of mass media spreading a tornado myth was after the 1999 Oklahoma tornado outbreak, where TIME magazine ran a caption on a picture suggesting that highway overpasses were safer tornado shelters than houses. The spread of some myths can be attributed to popular tornado-themed movies such as The Wizard of Oz and Twister.
Safety
Safest location in a building In 1887 the first book on tornadoes was written by John Park Finley, a pioneer in the field of tornado research. While it was a revolutionary book containing many breakthrough ideas, it contained a few ideas that have since been proven false.Tornado Myths – Tornado Fact vs. Fiction One of these was the idea that the northeast or east part of a structure was the least safe, and should be avoided when seeking shelter from a tornado.
This myth was derived from two misconceptions: First, that tornadoes always travel in a northeasterly direction, and second, that debris from a structure will be carried away in the direction of the tornado's propagation, leaving anyone taking shelter on the side of the structure facing the tornado's approach unharmed. The seriousness of these misconceptions began to be revealed in the 1960s and 1970s, when surveys of major tornado damage in residential areas showed that the section of a house in the direction of the tornado's approach is actually the least safe. Additionally, many tornadoes have traveled in directions other than northeasterly, including the Jarrell tornado (F5 on the Fujita scale), which moved south-southwesterly. Because determining a tornado's direction of approach can take time away from seeking shelter, official advice is to seek shelter in an interior room on the lowest floor of a building, under a staircase, I-beam, or sturdy piece of furniture if possible.
Opening windows to reduce tornado damage One of the oldest pieces of tornado folklore is the idea that tornadoes do most of their damage due to the lower atmospheric pressure at the center of a tornado, which causes the house to explode outward. The supposition was that opening windows helps to equalize the pressure. Cited link is not found.
The source of this myth is from the appearance of some destroyed structures after violent tornadoes. When one wall receives the extreme pressure of tornado winds, it will likely collapse inward. This then leads to a considerable outward pressure on the three remaining walls, which fall outwards as the roof falls down, creating the impression of a house which has exploded. Damage surveys of "exploded" houses usually show at least one wall that was blown inward. Additionally, if the roof is lifted before any walls fall, the walls can fall in any direction. If they fall outward, this structure can also appear to have exploded.
In even the most violent tornadoes, there is a pressure drop of only about 10%, which is about . Not only can this difference be equalized in most structures in approximately three seconds, but if a significant pressure differential manages to form, the windows will break first, equalizing the pressure. Additionally, as the windows are the most fragile parts of a house, in a significant tornado flying debris will likely break enough windows to equalize any pressure difference fairly quickly. Regardless of any pressure drop, the direct effects of a tornado's winds are enough to cause damage to a house in all but the weakest tornadoes.
Current advice is that opening windows in advance of a tornado wastes time that could be spent seeking shelter. Also, being near windows is very dangerous during a severe weather event, possibly exposing people to flying glass.
Using highway overpasses as shelter
There are several documented cases of people surviving under highway overpasses, but scientists warn against using them for protection. From scientific lessons learned, meteorologists insist that overpasses are insufficient shelter from tornado winds and debris, and may be among the worst places to take refuge during a violent tornado. The embankment under an overpass is higher than the surrounding terrain, and the wind speed increases with height. Additionally, the overpass design may create a wind tunnel effect under the span, further increasing the wind speed. Many overpasses are completely exposed underneath and most lack hanging girders or a crawlspace-like area to provide sufficient protection from debris, which can travel at high speeds even in weak tornadoes. People stopping underneath overpasses may also block the flow of traffic, putting others in danger.
Escaping a tornado in a vehicle Often people try to avoid or outrun a tornado in a vehicle. Although cars can travel faster than the average tornado, the directive from the National Weather Service is for house-dwellers in the path of a tornado to take shelter at home rather than risk an escape by vehicle. This is a result of several factors and statistics. An interior room inside a well-built frame house (especially one with a basement) provides a reasonable degree of protection from all but the most violent tornadoes. Underground tornado shelters, as well as extremely strong structures such as bank vaults, offer almost complete protection. Cars, on the other hand, can be heavily damaged by even weak tornadoes, and in violent tornadoes they can be thrown large distances, even into buildings. High-profile vehicles such as buses and tractor trailers are even more vulnerable to high winds.
There are many reasons to avoid cars when a tornado is imminent. Severe thunderstorms that produce tornadoes can produce flooding rains, hail, and strong winds far from the tornado-producing area, all of which can make driving difficult or even impossible. Any of these situations can leave drivers stranded in the path of the tornado far from substantial shelter. When coupled with driver panic, they may also result in dangerous but preventable accidents. This situation would be magnified greatly if all the residents of a warned area left in their vehicles, which would cause traffic jams and accidents as the tornado approached. Numerous victims of the deadly Wichita Falls, Texas, tornado on April 10, 1979, died in their vehicles in such a situation.
If a person spots a nearby tornado while driving, the official National Weather Service directive has been for the individual to abandon the car and seek shelter in a ditch or culvert, or substantial shelter if nearby. Far-away, highly visible tornadoes, however, can be successfully avoided by driving across (not ahead of) its apparent path. Despite dangers inherent with operating a vehicle during a tornado, given sufficient advance warning, mobile home residents have been instructed by the National Weather Service to drive to the nearest secure shelter during a warning.
Weak tornadoes
Despite being considered "weak" on the Enhanced Fujita scale or the Fujita scale, (E)F0 and (E)F1 tornadoes can be a source of significant injuries or even deaths. They can completely destroy mobile homes well before other structures receive significant damage. A 1978 F1 tornado struck Osage County, Kansas, causing the Whippoorwill tourist boat to capsize, resulting in the drowning of 16 passengers, among the highest tornadic death tolls in Kansas history. On March 31, 2023, an EF1 tornado struck the Apollo Theatre of Belvidere, Illinois, causing the building to collapse onto a sold-out concert, resulting in one fatality and 48 injuries. That same day another EF1 tornado struck urban areas of Tupelo, Mississippi, destroying a Cooper Tire & Rubber Company plant and resulting in over $100,000,000 in damage.
Tornado behavior Tornadoes skipping houses Several different phenomena have lent credence to the idea that tornadoes "skip" houses, like a person jumping over hurdles. Tornadoes vary in intensity along their path, sometimes drastically over a short period and distance. If a tornado was causing damage, then weakened to the point where it could cause no damage, followed by a re-intensification, it would appear as if it skipped a section. Occasionally with violent tornadoes, a smaller subvortex within a tornado will completely destroy a structure next to another building that appears almost unscathed and thus apparently skipped over.
It is true that a house between two destroyed houses can be undamaged, but this is not the result of a tornado skipping, as some previously thought. After the 1974 Super Outbreak, Ted Fujita studied many films of tornadoes from that day. Included in his review was damage and tornado film footage of F4 and F5 tornadoes. Fujita concluded that multiple vortices, highly volatile tornadic satellites transiting within a parent tornado at high speeds, are responsible for making tornadoes appear to skip houses. The phenomenon of satellite tornadoes, where a smaller tornado orbits a larger companion tornado, can also lead to gaps in damage between the two tornadoes.
Weaker tornadoes, and at times even stronger tornadoes, can occasionally lift, meaning their circulation ceases to affect the ground temporarily. The result is an erratic and discontinuous linear damage path, leading to the term skipping tornado. These discontinuities tend to occur over areas larger than the small neighborhoods where the house-skipping effect is observed, except possibly at the time of the birth and organization of the tornado. This situation is not commonly observed and the term is now rarely applied. Typically, when one tornado weakens and another forms, the process of successive parent mesocyclones forming and decaying is known as cyclic tornadogenesis, thus leading to a series of tornadoes spawned by the same supercell. This series of tornadoes is known as a tornado family.
Association of size with intensity