Tornado Warning Systems
Tornadoes can not be prevented since they form on their own, but we can plan to prevent injuries and deaths from tornadoes or least reduce these numbers. To do this, we need to alert the public of a tornado or a storm that could turn into a tornado before it hits their area so they can plan accordingly. Warning systems like Doppler Radars, sirens and NOAA radios can help alert the public and save lives.
Doppler Radars
Doppler Radars are able to detect tornadoes or storms that may turn into tornadoes. Most tornado warnings issued are because Doppler Radars were able to detect a tornado or a storm that could turn into a tornado. These type of radars work very similar to a normal radar, except they have an extra advantage. Normal radars work by having the antennae (bowl-shaped form) turn and release short bursts of rapid waves called pulses. Pulses travel through the atmosphere at the speed of light and hit targets. The antennae records the direction of the pulses it sent out and it records the distance that a pulse leaves the antennae, hits the target and then have the reflected pulse come back. By recording this data, the antennae can calculate how far the target is from the antennae. The advantage to Doppler Radars is that you can also determine the position of the target in addition to the location of the target. Doppler Radars' antennae keeps track of the phase (shape, position, etc.) of the released pulse so when the reflected pulse comes back, the antennae can calculate the differences between the released pulse and the reflected pulse. These differences in phase are called shifts in phase, which allows us to determine whether the target is moving towards the radar or away from it. If the target is moving towards the radar, there will be a positive shift in the frequency of the radar signal. If the target is moving away from the target, then there will be a negative shift in the frequency of the radar signal. These changes in frequency allow us to view motion in the atmosphere. By being able to view the atmosphere, development of tornadoes can be monitored. The antennae can also do scans of the area around as it rotates. It scans the different elevations so once the scan is over, there will be a 3-D scan of the atmosphere around the radar.
Sirens And NOAA Radios
Not all warnings are given out on TVs or radios, there is another system, sirens. Sirens are designed to alert people outside that there is a tornado coming or a storm that is coming that may turn into a tornado. The sirens are activated on a computer either by a city or county official, police officer, firefighter or emergency manager. Usually when there is a siren system, there are multiple sirens throughout the county to maximize sound. When the sirens are activated, they release sound waves; these sound waves then spread out from the siren and travel in a straight line. When the sound waves come into contact with an object, they will either reflect off the object or diffract (bend around the object). After either diffracting or reflecting, they will continue to travel in a straight line to people's ears. When you hear the sirens and see the tornado or storm approaching the area, you should immediately get to shelter. If you hear the sirens and know the tornado or storm is far away, but approaching soon, help others find shelter. Once you are in shelter, you should stay updated with either local news stations on TV or the radio to keep getting updates on the tornado or storm. The sirens will only sound for about three minutes, but after they are done sounding, it does not mean that the threat has passed. Since not all areas of Missouri have a siren system, it is best for families in those areas to either have TV or a NOAA radio. If you do not have a TV, it is highly recommended to have a NOAA radio. A NOAA radio is a like smoke detector, it will tell you when there has been a tornado warning for your area. The warnings they give out will be accurate since NOAA is accurate in their research so be sure to listen to them. NOAA will be serving its listeners 24/7 so don't worry about a tornado approaching your area in the middle of the night and not knowing about it. NOAA radios are sold at most electronic stores so they are easy to find and get.
Next Steps
Once you get into a shelter, in addition to staying updated with either a TV or a NOAA radio, you should get to the lowest level of the shelter, preferably the basement. For extra protection, you should get underneath the stairway and create a wall around you. If you do not have a basement, then get to the lowest level or room of the shelter. Stay in the center of the room, away from the windows and doors. Try to create as much of a wall around you as possible or get underneath a sturdy table. It is best to get to the lowest level of your shelter because as a tornado knocks down trees and other structures that are on ground-level, friction is created, causing the tornado to have less of an impact on stuff that is below ground. After the tornado is over, you should help injured people or trapped people. You should also clean up medicines, bleach and other flammable liquids and leave the area if gas or burning fumes are present or if the building is damaged. In addition to these actions after a tornado, you should also shut off your electricity and do not light a match because it could ignite spilled gas from the tornado (if there is any) and cause an explosion. So by following these steps and listening to warnings, we can reduce the injury and death numbers caused by tornadoes.