Tornadoes, sometimes also called Twisters, or less accurately Cyclones, are nature’s most violent storms.
Tornadoes can and do occur at any time of the year, but in southern states, peak tornado occurrence is March through May, while peak months in northern states are during the summer.
Statistically, tornadoes are most likely to occur between 3 and 9 p.m. but have occurred at all hours.
Spawned from powerful thunderstorms, tornadoes can cause fatalities and devastate a neighborhood in seconds. A tornado appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach as high as 300 miles per hour. Damage paths can be in excess of one mile wide and 50 miles long. Every state is at some risk from this hazard.
However, there are parts of the world that are more prone to Tornadoes than others. For example the United States has a so-called “Tornado Alley” stretching encompassing the Great Plains states between the Rocky and Appalachian Mountains. But as recent headlines have shown, given the worlds shifting weather patterns, devastating tornadoes can occur almost anywhere.
Some Things You Should Know About Tornadoes
- They can strike quickly, with little or no warning.
- In the U.S the average tornado moves Southwest to Northeast, but tornadoes have been known to move in any direction.
- Tornadoes often accompany tropical storms and hurricanes as they move onto land.
- Waterspouts are tornadoes that form over water.
Before a Tornado
Listen to NOAA Weather Radio or to commercial radio or television newscasts for the latest information. In any emergency, always listen to the instructions given by local emergency management officials.
Be alert to changing weather conditions. Look for approaching storms.
- A Tornado Watch Means: Tornadoes are possible. Remain alert for approaching storms. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio or television for information.
- A Tornado Warning Means: A tornado has been sighted or indicated by weather radar. Take shelter by going immediately underground to a basement, storm cellar or an interior room (closet, hallway or bathroom).
Be sure you know your community’s warning system. Communities in high-risk areas of tornadic activity have different ways of warning residents about tornadoes, with many having sirens intended for outdoor warning purposes. Tornadoes can and do happen with little or no warning, but to prepare in advance you should:
- Already have picked and prepared a safe room in your home where household members and pets should escape to during a tornado. This should ideally be in a basement or storm cellar. Lacking that, use an interior room on the lowest floor of the house without any windows.
- Practice periodic tornado drills so that everyone in your family knows what to do if a tornado is approaching.
- Prepare for high winds by removing diseased and damaged limbs from trees.
- Move or secure lawn furniture, trashcans, hanging plants or anything else that can be picked up by the wind and become a projectile.
How To Prepare a Wind Safe Room
If you live in an area prone to high winds or tornadoes, even if your residence has been “built to code” that does not mean it can withstand winds from extreme events such as tornadoes and major hurricanes. The purpose of a safe room or a wind shelter is to provide a space where you and your family can seek refuge that provides a higher level of protection. You can build a safe room in one of several places in your home.
- Your basement (best choice if you have one)
- Atop a concrete slab-on-grade foundation or garage floor.
- An interior room on the first floor.
Safe rooms built below ground level provide the greatest protection, but a safe room built in a first-floor interior room also can provide the necessary protection. Below-ground safe rooms must be designed to avoid accumulating water during the heavy rains that often accompany severe windstorms.
To protect its occupants, a safe room must be built to withstand high winds and flying debris, even if the rest of the residence is severely damaged or destroyed. Consider the following when building a safe room:
- The safe room must be adequately anchored to resist overturning and uplift.
- The walls, ceiling and door of the shelter must withstand wind pressure and resist penetration by windborne objects and falling debris.
- The connections between all parts of the safe room must be strong enough to resist the wind.
- Sections of either interior or exterior residence walls that are used as walls of the safe room must be separated from the structure of the residence so that damage to the residence will not cause damage to the safe room.
Complete design and construction plans for building a safe room can be downloaded from FEMA at: http://www.fema.gov/library/viewRecord.do?id=1536
You Can Further Protect Your Home From High Winds By:
- Protecting windows and doors with covers
- Reinforcing or replacing garage doors
- Removing trees and potential windborne missiles
- Securing metal siding and metal roofs
- Securing composition shingle roofs
- Bracing gable end roof framing
If Tornadoes Are in the Area, Look for the Following Danger Signs:
- Dark, often greenish sky
- Large hail
- A large, dark, low-lying cloud (particularly if rotating)
- Loud roar, similar to a freight train.
- If you see approaching storms or any of the danger signs, be prepared to take shelter immediately.
During a Tornado
Tornado intensities are classified on the Fujita Scale with ratings between F-0 (weakest) to F-5 (strongest). Tornadoes are capable of completely destroying even well-made structures, uprooting trees, and hurling objects through the air like deadly missiles.
If you are under a tornado warning, seek shelter immediately! Most injuries associated with high winds are from flying debris, so remember to protect your head. If available, put on a bicycle or motorcycle helmet to protect yourself from head injuries.
Mobile homes are not safe during tornadoes or other severe winds. Never seek shelter in a hallway or bathroom of a mobile home. If you live in a mobile home and Tornadoes are threatening, d not wait until you see or hear the Tornado. If you have access to a sturdy shelter or a vehicle, abandon your mobile home immediately and get to the nearest sturdy building or shelter.
If you are in a more secure structure (residence other than a mobile home, small building, school, nursing home, hospital, factory, shopping center, high-rise building) then you should:
- Go to your pre-designated shelter area such as a safe room, basement, storm cellar, or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Put as many walls as possible between you and the outside. Get under a sturdy table and use your arms to protect your head and neck.
- In a high-rise building, go to a small interior room or hallway on the lowest floor possible.
- If available, put on a bicycle or motorcycle helmet to protect yourself from head injuries.
- Put on sturdy shoes.
- Do not open windows.
If you are caught outside and cannot get to any shelter:
- Immediately get into a vehicle, buckle your seat belt and try to drive to the closest sturdy shelter.
- If your vehicle is hit by flying debris while you are driving, pull over and park.
- Stay in the car with the seat belt on. Put your head down below the windows; cover your head with your hands and a blanket, coat or other cushion if possible.
- If you can safely get noticeably lower than the level of the roadway, leave your car and lie in that area, covering your head with your hands
- Do not get under an overpass or bridge. You are safer in a low, flat location.
- Never try to outrun a tornado in urban or congested areas in a car or truck. Instead, leave the vehicle immediately for safe shelter.
- Watch out for flying debris. Flying debris from tornadoes causes most fatalities and injuries.
When the Storm Passes
Injury may result from the direct impact of a tornado, or it may occur afterward when people walk among debris and enter damaged buildings. A study of injuries after a tornado in Marion, Illinois, showed that 50 percent of the tornado-related injuries were suffered during rescue attempts, cleanup and other post-tornado activities. Nearly a third of the injuries resulted from stepping on nails.
Because tornadoes often damage power lines, gas lines or electrical systems, there is a risk of fire, electrocution or an explosion. Protecting yourself and your family requires promptly treating any injuries suffered during the storm and using extreme care to avoid further hazards.