The number one factor in helping to avoid physical harm from a tornado is early warning. In the U.S. the National Weather Service (NWS) is the service that issues tornado warnings and alerts. Days in advance the NWS is watching our weather looking for just the perfect combination of moisture, instability, lift, and wind shear. These are the unique four ingredients of a tornado. But those alone will not cause a tornado necessarily. The strength of the storm, the amount of lift, the amount of moisture and the temperatures both at ground level and above, the wind structures that make a storm rotate as a supercell, all of these come into play. And then the experts try to map the areas where these conditions are most likely to occur.
But even with all of the modeling, calculating and predictions, we still get it wrong sometimes and tornados occur without warning. We've become better with our predictions. In March of 1925, the "Tri-state" tornado killed approximately 695, when our abilities to predict and warn about tornados were not as good as they are today.
In April of 1974 tornados killed 308 people on day one of the "Super Outbreak" tornados which lasted two days when 147 tornados touched down. 48 of those tornados were killers. 7 produced damage rated F5, the maximum possible, and 23 were rated F4.
The biggest tornado on record in the U.S. was the Hallam, Nebraska F4 tornado in May of 2004 which was reported to be two and a half miles wide.
May of 2003 set the record (since modern tornado record keeping began in 1950) for the most tornados in any one single month. 543. This shattered the prior record of 399 set in June of 1992.
The highest wind speed of any tornado ever recorded was 302 mph (in May of 1999 near Bridge Creek, OK) but ground-level wind speed of an F5 tornado has never been directly measured.
The most expensive tornado was in Topeka, KS in June of 1966, when adjusted for inflation to 2007 dollars would have been close to $1.6B. The Bridge Creek-Moore-Oklahoma City-Midwest City, OK, tornado of May 1999 ranks first in actual dollars, but third when adjusted for inflation.
So what should you do to protect yourself? The National Storm Prediction Center (SPC) give us several things we can do, although is quick to point out that there is no such thing as guaranteed safety inside a tornado, and that freak accidents will always occur. The most violent tornados can completely level almost any house as well as the occupants. The good news is, F5 tornados are rare and most tornados are actually much weaker and can be survived if you follow these safety tips. Thanks goes out to the SPC for providing these tips and advice on how to survive a tornado.
Tornado Safety Tips
- Prevention and Practice - Have a plan in place.
- Know the Signs of a Tornado - Stay alert and look for the signs.
- House with a Basement - Go to basement, seek cover, avoid being under heavy objects upstairs.
- House with no Basement, or an Apartment - Avoid windows. Seek the lowest floor, small center room.
- Office Building or Skyscraper - Seek interior room or interior stairwell (which can take you to a lower/safer level).
- Mobile Home - Get out!
- At School - Follow the drill!
- In a car or truck - Get out and seek sturdy shelter.
- In the open outdoors - Seek sturdy shelter.
- In a Mall or a large store - Seek a small, interior bathroom.
- In a Church or a theater - If no interior bathroom, crouch face down under pews, protecting head.
- After the tornado - Stay together!
Tornado Safety Tips
- Prevention and Practice - At home, have a family tornado plan in place, based on the kind of dwelling you live in and the safety tips below. Know where you can take shelter in a matter of seconds, and practice a family tornado drill at least once a year. Have a pre-determined place to meet after a disaster. Flying debris is the greatest danger in tornadoes; so store protective coverings (e.g., mattress, sleeping bags, thick blankets, etc) in or next to your shelter space, ready to use on a few seconds' notice. When a tornado watch is issued, think about the drill and check to make sure all your safety supplies are handy. Turn on local TV, radio or NOAA Weather Radio and stay alert for warnings. Forget about the old notion of opening windows to equalize pressure; the tornado will blast open the windows for you! If you shop frequently at certain stores, learn where there are bathrooms, storage rooms or other interior shelter areas away from windows, and the shortest ways to get there. All administrators of schools, shopping centers, nursing homes, hospitals, sports arenas, stadiums, mobile home communities and offices should have a tornado safety plan in place, with easy-to-read signs posted to direct everyone to a safe, close by shelter area. Schools and office building managers should regularly run well-coordinated drills. If you are planning to build a house, especially east of the Rockies, consider an underground tornado shelter or an interior designated "safe room."
- Know the Signs of a Tornado:
a. Strong, persistent rotation in the cloud base.
b. Whirling dust or debris on the ground under a cloud base -- tornadoes sometimes have no funnel.
c. Hail or heavy rain followed by either dead calm or a fast, intense wind shift. Many tornadoes are wrapped in heavy precipitation and can't be seen.
d. Day or night: Loud, continuous roar or rumble, which doesn't fade in a few seconds like thunder.
e. At Night: Small, bright, blue-green to white flashes at ground level near a thunderstorm (as opposed to silvery lightning in clouds). These mean power lines are being snapped by very strong wind, maybe a tornado.
f. At Night: Persistent lowering from the cloud base, illuminated or silhouetted by lightning
- House with a Basement - Avoid windows. Get in the basement and under some kind of sturdy protection (heavy table or work bench), or cover yourself with a mattress or sleeping bag. Know where very heavy objects rest on the floor above (pianos, refrigerators, waterbeds, etc.) and do not go under them. They may fall down through a weakened floor and crush you.
- House with no Basement, or an Apartment - Avoid windows. Go to the lowest floor, small center room (like a bathroom or closet), under a stairwell, or in an interior hallway with no windows. Crouch as low as possible to the floor, facing down; and cover your head with your hands. A bathtub may offer a shell of partial protection. Even in an interior room, you should cover yourself with some sort of thick padding (mattress, blankets, etc.) to protect from falling debris in case the roof and ceiling fail.
- Office Building or Skyscraper - Go directly to an enclosed, windowless area in the center of the building -- away from glass. Then, crouch down and cover your head. Interior stairwells are usually good places to take shelter, and if not crowded, allow you to get to a lower level quickly. Stay off the elevators; you could be trapped in them if the power is lost.
- Mobile Home - There's no other option here. Get out! Even if your home is tied down, you are probably safer outside, even if the only alternative is to seek shelter out in the open. Most tornadoes can destroy even tied-down mobile homes; and it is best not to play the low odds that yours will make it. If your community has a tornado shelter, go there fast. If there is a sturdy permanent building within easy running distance, seek shelter there. Otherwise, lie flat on low ground away from your home, protecting your head. If possible, use open ground away from trees and cars, which can be blown onto you.
- At School - Follow the drill! Go to the interior hall or room in an orderly way as you are told. Crouch low, head down, and protect the back of your head with your arms. Stay away from windows and large open rooms like gyms and auditoriums.
- In a car or truck - Cars are extremely dangerous in a tornado. If the tornado is visible, far away, and the traffic is light, you may be able to drive out of its path by moving at right angles to the tornado. Otherwise, park the car as quickly and safely as possible -- out of the traffic lanes. [It is safer to get the car out of mud later if necessary than to cause a crash.] Get out and seek shelter in a sturdy building. If in the open country, run to low ground away from any cars (which may roll over on you). Lie flat and face-down, protecting the back of your head with your arms. Avoid seeking shelter under bridges, which can create deadly traffic hazards while offering little protection against flying debris.
- In the open outdoors - If possible, seek shelter in a sturdy building. If not, lie flat and face-down on low ground, protecting the back of your head with your arms. Get as far away from trees and cars as you can; they may be blown onto you in a tornado.
- In a Mall or a large store - Do not panic. Watch for others. Move as quickly as possible to an interior bathroom, storage room or other small enclosed area, away from windows.
- In a Church or a theater - Do not panic. If possible, move quickly but orderly to an interior bathroom or hallway, away from windows. Crouch face-down and protect your head with your arms. If there is no time to do that, get under the seats or pews, protecting your head with your arms or hands.
- After the tornado - Keep your family together and wait for emergency personnel to arrive. Carefully render aid to those who are injured. Stay away from power lines and puddles with wires in them; they may still be carrying electricity! Watch your step to avoid broken glass, nails, and other sharp objects. Stay out of any heavily damaged houses or buildings; they could collapse at any time. Do not use matches or lighters, in case of leaking natural gas pipes or fuel tanks nearby. Remain calm and alert, and listen for information and instructions from emergency crews or local officials.