Should you be trying to escape a tornado

Correct behavior in tornadoes

With the current methods, tornadoes cannot be predicted (Friedrich, 2017). The common weather forecast models work with a resolution of two to three kilometers. However, tornadoes, as they also occur regularly in Germany, have a very small extent of up to a few hundred meters, so that they cannot be recognized as small-scale phenomena by weather radar or weather satellites. Relatively reliable predictions, such as with hurricanes - i.e. days in advance - are impossible with tornadoes. Experts can identify supercells a maximum of 18 hours in advance, but these do not necessarily lead to a tornado and whose exact path cannot be foreseen (Friedrich, 2017; DWD).

Therefore, people who are outdoors are usually on their own. This concerns the detection of a tornado, but also the ad hoc correct protective behavior. But how can you even recognize a tornado early? One thing is clear: if you see funnel-like, rotating hoses of cloud in the sky that have not yet reached the ground, there is a high risk of tornado in the next 15 to 60 minutes. But there are also other signs: If so-called super cells or mighty 'wall clouds', as the Americans call them, form, these are usually harbingers of the most devastating tornado variants. Mesocyclones are formed in supercells; they are, so to speak, the engine of rotation (DWD). But tornadoes do not always have this characteristic cloud tube. Sometimes you can only recognize them by the fact that dust and earth are suddenly and occasionally whirled up on the ground. If this happens in combination with conspicuous cloud formations, it could be a tornado (DWD). Incidentally, the size and shape of a tornado say nothing about its strength (Edwards, 2020, "Spotting and Chasing / What is a" wedge "tornado? A" rope "tornado?"). Since tornadoes often only extend a few dozen to a few hundred meters, they can usually be avoided on foot. To do this, it is important to first observe the tornado and to record the direction in which the tornado moves. Then those affected can move out of the direction of pull. A safety distance of one kilometer from a tornado is usually sufficient.

How much protection does the car offer?

Many people believe that behavior in a tornado is similar to that in a severe thunderstorm. But there are major differences. If you are surprised by a tornado, a car - very unlike a thunderstorm - offers almost no protection. During a thunderstorm, the vehicle serves as a Faraday cage. In a severe tornado, however, cars can easily be lifted tens of meters in the air. In the event of smaller tornadoes, a moving car can also be blown off the road.

Under no circumstances should a car be pulled under bridges or underpasses, recommends the US Weather Service (National Weather Service, 2014). Severe tornadoes, such as those that occur in the United States, can cause even seemingly stable bridges to collapse. Even if these severe tornadoes do not occur in Germany, as in the USA, there are small-scale cyclones in this country more often than expected. According to the reinsurer Munich Re, the European Weather Service (ESWD) is assuming 20 to 60 events per year for Germany (Eichner, 2016), and 300 to 400 tornadoes are known for all of Europe. When dust is blown up, the view of such a weather event can be so severely restricted within a short time that it is no longer possible to continue driving safely. The key here is to brake the vehicle quickly and bring it to a stop, as in thick fog or a snow storm.

Looking for security in buildings or in the open field

In order not to be hit by swirling rubble, one should, if possible, go to basements and massive stone houses, and stay away from windows and doors (Friedrich, 2017). If there are no stable escape buildings nearby and it is not possible to dodge the tornado, it will help to lie flat on the ground. It is even better to take refuge in a pit, hollow or ditch, according to American experts (Severe Weather Safety Tips). You have to wait there until you can really be sure that the tornado has passed. The duration of a tornado is between a few seconds and up to an hour, with most tornadoes lasting around 10 minutes (Bildungswiki Klimawandel). With a bit of luck, weaker tornadoes will pass over you and the likelihood of being hit by blown objects will decrease. Maybe there is a gorge nearby to visit. These are also relatively safe places.

However, in connection with tornadoes, the risk from heavy rain is not insignificant. The recommendation to lie down in a pit or a ravine therefore depends on the circumstances. This allows you to protect yourself somewhat from the extreme wind speeds, but - due to the enormous amount of precipitation - ditches, ravines, hollows or cellars that suddenly fill with water (a particularly common risk in Germany) are just as dangerous as the high wind speeds.

Tornadoes in the USA

Approximately 1,200 tornadoes are counted in the United States each year (NSSL). They can be up to one and a half kilometers wide and cover a distance of over 80 kilometers on the ground. Tornadoes rotate even faster than hurricanes and reach speeds of more than 320 kilometers per hour. The DWD reports from already measured maximum speeds of over 500 kilometers per hour. Tornadoes often accompany hurricanes.

Tornadoes in the United States move forward at an average of 30 mph (48 km / h). However, the range is considerable: from stationary to a speed of 110 km / h, everything is possible. 88 percent of all tornadoes are weak. They only last one to ten minutes and can reach wind speeds of up to 177 km / h (110 mph). Strong tornadoes only make up one percent of tornadoes, but are responsible for 70 percent of deaths. They last up to an hour and reach wind speeds of over 267km / h (166mph).

Tornadoes can occur at any time of the day or night and form at any time of the year. They are particularly common in the southeastern United States and the Central Plains, between the Arkansas and Platte rivers. Here, dry and cold air often meets moist and warm air from the Gulf of Mexico. So far, however, tornadoes have occurred in all American states. It is a misconception that mountain areas are safe from tornadoes. But the fact is: tornadoes are possible anywhere in the US. For example, a tornado near the famous Yellowstone National Park left a trail of devastation at an altitude of 2,600-3,000 meters. Even if there is talk of a 'tornado season' in the USA, it does not actually exist. An accumulation of tornadoes can be observed in late May, early June for the Southern Plains and in June and July for the Northern Plains, but tornadoes are just as possible in the other months (NSSL). There is no such thing as a “tornado season”, even if the common term suggests it.

Around half of the victims of tornadoes in the US are people who live in mobile homes. The houses are usually not firmly anchored in the ground and are therefore particularly at risk. Research shows that despite warnings, people often leave their homes far too late.

Is the risk of tornadoes increasing?

There are currently no valid studies that show that the number of tornadoes is increasing. In both the US and Europe, the number of tornadoes occurring is stable. Tornadoes are difficult to detect. This is why the data sets that scientists can access are fraught with uncertainties. With the measurement methods used to date, it is difficult to determine whether climate change will lead to an increase in tornadoes. There are indications that the intensity of thunderstorms and storms is also increasing in Germany and Europe. In the case of tornadoes, the black box is still relatively large. However, it is known that tornadoes can occur in many regions of the world, including in this country. Many people in Germany have seen and observed tornadoes. It is therefore good to be sensitized to this natural hazard, because one thing is certain: tornadoes often come as a surprise, but you don't have to be surprised by them in every situation. If you have the sky in view during thunderstorms, you can avoid a possible tornado and seek shelter in the right place.

And one more surprising fact at the end: In addition to the USA, Argentina and Bangladesh are the countries where this natural phenomenon can most likely be expected.

Text: Jana Kandarr (ESKP)

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Additional information


Published: 04.03.2019, 6th volume

Citation reference: Kandarr, J. (2019 March 4). Correct behavior in tornadoes. Earth System Knowledge Platform [], 6. doi: 10.48440 / eskp.067

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