Formation Ingredients
The key atmospheric ingredients that lead to tornado potential are instability - warm moist air near the ground, with cooler dry air aloft and wind shear - a change in wind speed and/or direction with height. An unstable airmass promotes the development of strong updrafts, while wind shear will further increase the strength of the updraft, and promotes the rotation from which tornadoes are produced.
All thunderstorms have the potential to produce tornadoes, but the type of storm that is most commonly tornadic is the supercell. This very severe, long-lived thunderstorm contains circulation aloft (mesocyclone) that grows upward through the storm and downward toward the ground. When conditions are favorable, tornadoes will be produced. Supercells may produce strong, violent tornadoes, or several tornadoes over a period of several hours. The two most recent major supercell outbreaks in north or central Georgia was during the Palm Sunday Tornadoes of March 27,1994 and the Southeast Tornado Outbreak of April 27-28, 2011.
Detection
Our WSR-88D Doppler radar can detect the circulation associated with a tornado producing thunderstorm. Once the circulation is identified, a warning is issued. However, Doppler radar is not perfect, because it can only indicate rotation aloft, and does not indicate what may be happening on the ground. This is where our storm spotters come in. Only feedback from someone in the area can confirm whether the radar signature is associated with a tornado.
North and Central Georgia Tornado History
Georgia has experienced almost all strengths of tornadoes, ranging from EF-0 to EF-4. Although the state has never experienced an EF-5, it does not mean it can't happen! The below graphics depict both past track and strength of north and central Georgia tornadoes.
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North and Central Georgia Tornado Tracks | Number of Tornadoes by Month |
| Note: Although one EF-5 tornado is shown in the images above, it was an EF-5 in Alabama that weakened as it moved into Georgia. No EF-5 tornadoes have occurred in Georgia. | |
Safety Information
It is important to have a safety plan before you need to act. Tornadoes can develop rapidly so be prepared to act quickly! The preparedness guide for thunderstorms, tornadoes and lightning suggests the following safety rules for tornadoes:
- Move to an underground shelter, basem*nt or safe room.
- If the above is not available, more to a small, windowless interior room or hallway on the lowest level.
- Abandon mobile homes and go to the nearest sturdy building or shelter immediately.
- If you are caught outdoors and a basem*nt or sturdy building is unavailable:
- Immediately get into a vehicle, buckle your seat belt and try to drive to the closest sturdy shelter.
- If flying debris occurs while you are driving, pull over and park. Now you have the following options as a last resort:
- Stay in your vehicle with the seat belt on. Put your head down below the windows, covering it with your hands and a blanket if possible.
- If you can safely get noticeably lower than the level of the roadway, exit your car, and lie in that area, covering your head with your hands.
The tornado damage from Coweta county, shown below, is an example of the importance of moving into an interior room. In this case, all of the outside walls were destroyed.
