What should you do after a tornado

How to act correctly in a tornado: seven rules

At breakneck speed, they leave paths of devastation: tornadoes not only cut their way through the USA, but also through Germany. The tornado officer of the German Weather Service (DWD) explains how to recognize them - and survive.

The air is humid and humid. It is warm, the thick storm clouds do not bode well. It will be stormy, but the clouds are pulling almost in the opposite direction of the wind, which tilts and shakes the trees.

Rule number 1: watch and leave!

If twisting funnel clouds that point towards the ground form and approach quickly, you only have one chance: No, don't unpack your smartphone, film, post on YouTube and hope for fame. Instead, watch exactly where the funnel is moving. And then let's get away. Immediately.

Tornadoes often cause severe damage. But mostly they move across open terrain, uproot trees, tear bushes from the ground and destroy buildings. But not always. Small settlements are also increasingly affected by a few houses. Because for a devastation it is often enough for the tornado to rage for only ten minutes, and as a result dozens of houses are uninhabitable.

Rule number 2: Be faster than the tornado or seek shelter!

The often life-threatening phenomenon is "mostly a very small-scale one", explains meteorologist Andreas Friedrich, tornado officer of the German Weather Service (DWD). "The diameter of a tornado is between a few meters and just under a kilometer." On this surface, the cloud funnel rotates around its own axis with tremendous energy. Weaker tornadoes have a lifespan of just two or three minutes - "ten minutes are the exception," says Friedrich. The funnel usually moves "at a speed of around 20 to 60 km / h through the landscape." This is an advantage in an emergency: "It doesn't move overland all too quickly, so you still have a chance to get away or to seek protection."

Rule number 3: Don't get into the dangerous funnel!

It becomes life-threatening when you get into the area in which the funnel is rotating. The meteorologists classify the turning speed according to the "Fujita scale", which was defined in 1971 by the Japanese storm researcher Tetsuya Fujita. A tornado of the weakest classes F0 and F1 rotates at 65 to 116 km / h. The highest speed ever measured is the F5 class, which reaches up to 512 km / h. The energy of the spinning wind is unimaginably great: "Railway wagons and trucks fly through the air, houses are destroyed. Windows, doors, satellite dishes, solar panels, steel girders, roofs and lanterns are now whirling around at tremendous speed. Whoever is hit has little chance . " Even in Germany there have been tornadoes of the highest categories.

Rule number 4: find the right room!

To survive a tornado, you should seek shelter inside buildings. "Go into the house, but never upstairs and far away from all windows. The basement is safest. If that doesn't work, you go to the middle of the house on the ground floor. Bathrooms without daylight or the guest toilet also offer security. Door to wait, "says Friedrich.

Rule number 5: win a distance of 500 meters!

When you are out and about, the rule is: "Full throttle off the trunk." The meteorologist recommends briefly observing the direction of the tornado and fleeing in the opposite direction as quickly as possible. "At a distance of about 500 meters you are out of danger."

Rule number 6: lay flat in a hollow!

"As far away from trees as humanly possible. Escape to a cellar somewhere." Whether you are hiking: into the meadow or the fields, looking for a depression or hollow, lie down flat with your face down and hope for luck. According to the German Weather Service, weaker tornadoes then pull over you "and the risk of being hit by objects flying around is the lowest."

Rule number 7: get away from vehicles!

Cars also offer no safety in higher tornado categories: "It is not a protection, it is life-threatening. The vehicle and its occupants can fly around or be hit by objects."

Are tornadoes increasing in Germany?

"In Germany we register between 20 and 60 tornadoes a year," says the weather expert. "The number of registered cases has increased in recent years," he reports, "but only because the number of unreported cases is decreasing. More and more people are reporting and documenting tornadoes. 20 years ago that was not the case, as there were no smartphones with them Internet access, photo and video cameras. "

The core area of ​​tornado formation on earth is the US state Oklahoma in the central southern United States. "There, ten times as many tornadoes occur annually over an area of ​​just one hundred square kilometers as in the whole of Germany," reports Friedrich. The meteorologist works closely with the experts from the forecast center of the American National Weather Services in Norman, Oklahoma.

Can you predict a tornado?

It is difficult to make reliable predictions as to whether and where exactly a tornado will form. The German Weather Service can initially only recognize a potential risk for up to 36 hours in advance, explains the expert. It is then only determined for a certain region an increased probability that tornadoes could occur in a relatively large area.

More accurate predictions for districts or individual locations are only possible if an observer informs the meteorologist promptly that a tornado or a preliminary stage, the so-called funnel clouds, has already been seen, says Friedrich. This then means that another tornado can occur within a few minutes.

How does the tornado come about?

A tornado occurs when there is very high humidity in a region, the ground is warm and the cloud base is no higher than 1 kilometer. If it is very cold above and warm on the ground during a thunderstorm front, there is a massive difference in air pressure. The warm, gaseous water vapor moves upwards, releasing massive amounts of energy that swirls. This creates two wind directions above and below, a "wind shear". This creates the rotation, which can even increase due to the tremendous energy.

Why this happens is not clear even among researchers. "There is therefore no early warning system," confirms Friedrich, "our satellite images and radar echoes do not help us here."

However, if "Storm Chaser", who have come together as trained storm warners, report a windpipe, the DWD can call up the wind changes, air pressure and temperature profiles as well as the cloud base in precisely this area with the warning management system supervised by Friedrich. In addition, there is the data from the model predictions. "If the threshold values ​​are exceeded, the first thing to do is to send a pre-alarm to the rescue services and the fire brigade. This is followed by a severe weather warning to the public. But we cannot yet predict exactly where the tornado will break out."

Difference Between Hurricanes and Tornadoes

In contrast to tornadoes, hurricanes are more predictable - but also more extensive. These cyclones arise over the sea. If the temperature of the water surface is at least 26 degrees, the water evaporates. If there is now a low, the probability is high that a corresponding weather phenomenon will occur.

By the way: If such hurricanes occur in the Indian Ocean, they are called cyclones.