Tornado Facts

What is a tornado?
A tornado, also referred to as a twister, is a spiral violent wind that can shatter anything in its path.  It is one of the most violent storms in nature.

Tornado and Lightning
Creative Commons License photo credit: tlindenbaum

Tornadoes vary drastically in intensity, speed, duration, size, color, and shape. The shape of a tornado can be formed as a large funnel cloud, a thin rope-like shape, or it can appear like an extremely wide rotating cloud without the appearance of a funnel-shape.  Even the color of tornadoes varies from dark gray or black, to light gray, and even white.  Tornadoes travel at different rates of speed and may last only moments or depending on its intensity may continue on its path much longer.

What’s The Difference Between A Tornado And A Funnel Cloud?
A funnel cloud is the same as a tornado with the exception that a funnel cloud does not touch ground.

How Long Does A Tornado Last?
On average a tornado has a lifespan of a few minutes; however, stronger more destructive tornadoes can last approximately an hour.

Do Tornadoes Always Rotate In The Same Direction?
Tornadoes will usually rotate counterclockwise or cyclonically, north of the equator.  South of the equator, tornadoes generally have a clockwise or anticyclonic rotation.  However, that is not a hard and fast rule because tornadoes can, and do, rotate in either direction.  There have even been documented cases of multiple cyclonic and anticyclonic tornadoes occurring at the same time within the same thunderstorm system.

What is a multivortex tornado?

The definition of vortex is a mass of whirling, spiraling, air or water resembling a whirlpool.   A multi-vortex, or multiple vortex, tornado is a fairly rare occurrence in which two or more tornadoes, or vortices, are present at the same time and often rotating around a common center or around each other.

How Far Does a Tornado Travel?
Tornadoes are erratic and unpredictable and touch down in just one area or travel distances of more than 100 miles.

Do Tornadoes Always Travel In The Same Direction?
Tornadoes can come from any direction and therefore do not always travel in the same direction; however, there are typical patterns of tornado movement which are driven by weather patterns.

Most tornadoes travel from southwest to northeast, or from west to east.  Tornadoes can change paths or backtrack at any time, which is caused by an outflow of winds from the core of a thunderstorm. Certain areas of the United States do tend to have a more likely direction that tornadoes will follow; for example, northwest-flow weather systems in northwestern Minnesota and hurricanes in south Texas create weather patterns that generally determine the same standard direction of travel for the path of a tornado in those areas.

When Is Tornado Season?
Tornadoes can occur all year long, though in the United States, in the Northern Hemisphere, the prime tornado season is between the months of March through August.

What Time Of Day Does A Tornado Usually Happen?
Tornadoes can occur at any time of day or night, but the most common time period for a tornado to strike is between noon and midnight, with an even higher occurrence between 4pm and 9pm.  Tornadoes are much more frequent during these hours because after the heat of the day is when weather conditions are typically most favorable for tornado formation.

Country with most tornadoes?
Tornadoes happen all over the world with the exception of Antarctica, but the country with the most tornadoes is the United States.  The U.S. ranks number one with an average of 1,000 tornadoes each year, with the majority of those occurring in the region known as Tornado Alley.  Canada has the second highest occurrence of tornadoes, averaging 100 tornadoes per year.

What Is Tornado Alley?
Tornado Alley is a well-known area in the plains states of the United States which is highly prone to frequent destructive tornadoes. The specific boundaries of this area are determined by data collected from weather patterns and can change from year to year.

The general area referred to as Tornado Alley where typically over 1,000 tornadoes occur each year, includes parts of Texas, Oklahoma, Kansas, Nebraska, Colorado, and South Dakota.  Other states in Tornado Alley where less intense tornadoes frequently occur are Arkansas, Louisiana, Mississippi, Iowa, Tennessee, Kentucky Wisconsin, and Minnesota.

Tornado Wind Speed
Typical wind speeds of a tornado most commonly clock in around 112 mph.  Lower intensity tornadoes have winds beginning at 30+ mph while the strongest recorded tornadoes have had winds recorded with speeds up to 318 mph.

The Fujita Scale
Dr. Ted Fujita (1920 – 1998) was a Professor in Geophysical Sciences at the University of Chicago. Dr. Fujita was a pioneer in research in the field of mesometerology as he studied the phenomena of tornadoes and hurricanes.  He actually became interested in tornadoes when he was growing up in Japan as he saw the intense damage from typhoons.  Although tornadoes are different from typhoons it sparked his interest.  Dr. Fujita became known as “Mr. Tornado” after he and his wife, Sumiko, devised the six-point scale measuring the intensity of tornadoes called the Fujita Scale.



In the image of the Fujita Scale below, you will see the six classifications which categorize the strength and intensity of tornadoes.

The weakest ranking is an F0 with winds ranging from 40 to 72 mph.  This would be a gusty wind causing minor roof and tree damage.

When a tornado reaches the F1 category at 112 mph it’s like a Category 3 hurricane, that lasts a lot less time but the winds are circling and damage occurs from all sides as seen when cars are tossed like toys and significant roof damage occurs.

Next on the scale is F2 with 113 to 157 mph which will unroof strongly built buildings and disintegrate mobile homes.

F3 on the scale reaches over 200 mph and even on strongly built homes walls are blown away, while weaker homes are completely swept away.

The F4 scale ranges from 207 to 260 mph and all walls are blown apart on strongly built homes and cars can be thrown 300 yards or more in the air.

The most intense ranking on the Fujita Scale is an F5 with the possibility of winds reaching speeds of 261 to 318 mph which would completely blow away even strongly built homes.




The Enhanced Fujita Scale

The original Fujita Scale was devised in 1971 and in 2007 the scale was updated and is now called The Enhanced Fujita Scale which categorizes tornadoes based on the damage it produces. Total destruction occurs during an EF5 tornado when strong-framed, well-built homes are leveled and even concrete structures are critically damaged.  The first recorded EF5 tornado measured with the Enhanced Fujita Scale was the Greensburg, Kansas tornado which occurred on May 4, 2007.


Tornado Damage

Devastating examples of tornado damage are shown in the short video above produced by the Associated Press.  Footage was compiled from a deadly tornado outbreak on April 25th through 28th, 2011, with April 27th being the most destructive.  This series of tornadoes became known as the 2011 Super Outbreak.  A total of 336 tornadoes occurred in 21 states from New York to Texas, four of which were ranked as EF5 category tornadoes.  The number of people killed are estimated at 346 people, with 239 of those deaths in Alabama.

This National Geographic video captures the violent fury and power of several tornadoes showing the incredible force of nature as one tornado lifts an entire house into the air, tossing and spinning it around in the air.


Tornado Safety Tips

Before A Tornado Occurs

  • Have a plan! Knowing how to respond and act quickly when a tornado materializes you can keep yourself, your family, friends, and co-workers safe.  You need to be prepared ahead of time and know where to go in a moment’s notice.  Have a previously designated safe place to go such as a basement or interior room.
  • Take a first aid and CPR class and keep a first aid kit in your basement or tornado shelter so you will be prepared and equipped in the event of an injury.
  • Stock your storm cellar or shelter with water, food, and first aid supplies.  Although you won’t need to remain in the shelter area very long, it is a safe place to keep some basic essentials in the event the storm is major and supplies you had in your home have been destroyed.  After a tornado you will most likely be without running water and electricity for a period of time and these items will be critical.
  • Keep a spare set of sturdy clothes, work gloves, and thick-soled shoes in your storm safe room for use after the tornado.  If it was a strong tornado you may be coming out of your safe area into broken glass and debris.

The above report from WDBJ news in Roanoake, Virginia covers some great tornado safety tips.


Have A Weather Radio With A Tornado Warning Alarm System
When severe weather is occurring stay informed by having as many ways as possible to receive weather updates and any notifications of a tornado watch or tornado warning.  Don’t rely on just one method in case an unforeseen problem arises.

Have a battery powered weather radio with an alarm feature that will sound in the event a tornado warning is issued, an NOAA weather radio is a good choice. You can purchase weather radios at electronics stores, department stores, and home improvement stores.

Storm information can also be obtained from a battery powered radio or television.  If electricity is on and internet signal is available an interactive tornado map is accessible online.

Local emergency authorities utilize various warning systems which will override cable television and radio programs with emergency announcements, reverse 911, and sirens.



Know the difference between a Tornado Watch and a Tornado Warning.

What Is A Tornado Watch?
During a tornado watch weather conditions exist in which tornadoes may form.  A tornado watch will usually last for about six hours and cover a large area.

What Is A Tornado Warning?
A tornado warning is an urgent message indicating that an actual tornado has either been sighted or indicated on radar.  Tornado warnings are valid for less than one hour and are issued for counties or portions of counties.

When a tornado warning is issued, take immediate action and seek shelter.

The tornado safety video above was created by the National Weather Service in Fort Worth/Dallas, Texas and provides valuable information on how to stay safe in various situations you may find yourself in during a tornado.


What Are The Signs Of A Tornado?
If weather conditions are present for possible tornadoes, know what to look for just before or as a tornado forms:

  • Strong rotation in the clouds
  • Large hail (the larger the hail, the stronger the storm)
  • Greenish black clouds
  • A funnel cloud before it touches down, but often a funnel cloud is not seen.

What To Do In A Tornado
At Home, School, Work, or Shopping

  • The safest place to be is in a tornado shelter, basement, or cellar.  Underground tornado shelters and above ground tornado shelters can be purchased and installed outside or inside and are made to withstand EF-5 tornadoes.  Another point worth mentioning is the false belief years ago that it was safer to take shelter in the southwest corner of a basement or cellar because of the direction tornadoes typically travel.  While it’s true tornadoes usually travel from the southwest to the northeast, the southwest corner of a basement is no safer than any other corner.
  • If an underground shelter is not available, go to a windowless, interior room on the lowest floor of the building you can get to.  Bathrooms are particularly good shelters.  Small closets and interior hallways are a good choice.
  • If possible pull a mattress or sleeping bag over you to protect you from flying debris. If not, then protect your head and neck by keeping your head down and clasping your hands together behind your neck.
  • Avoid auditoriums, gymnasiums, or any areas with wide span roofs.
  • DO NOT remain inside a mobile home, portable classroom, or construction trailers. As soon as the weather looks ominous, leave the mobile home and head to a solid structure.  If unable to do so, then as a last resort it is better to seek shelter on the ground outside. Lie flat in the nearest ditch or lowest ground area and shield your head with your hands.
  • Don’t bother to open windows in your house.  Opening windows does not give air an escape to prevent the roof from blowing off as believed in years past.

Driving In A Tornado

  • DO NOT try to outrun a tornado in your vehicle.  Cars and even large vehicles are tossed and blown about in a tornado.  Pull off at the nearest building, even a gas station or convenience store and take cover inside away from windows.
  • If you are stuck in traffic or are out in a wide open area and there is not building nearby, then your best option is to get out of your vehicle and find the lowest possible place to lie flat and cover your head with your hands in a ditch or culvert.
  • DO NOT use an overpass as protection from a tornado.  Overpasses are not safe shelters.


Immediately After A Tornado

  • Check on family members and/or others who are with you.
  • Provide emergency first aid if needed.
  • Wait for emergency personnel, but be prepared for the possibility that you may be on your own for quite some time.
  • Carefully assess the damage while taking the following life and death precautions:
  • Be extremely watchful for power lines.  Any downed power line could possibly still be live.
  • Don’t step in water puddles without specifically checking to make sure there are no electrical wires making contact with the puddle.
  • Watch for broken glass and other sharp objects.
  • If your home or office, or whatever location you may be at, is still standing but has suffered heavy damaged, then stay out of the structure because it could collapse.
  • DO NOT use matches or lighters in case natural gas lines or any nearby fuel tanks have sustained damage from the tornado.
  • Listen for emergency information and instructions from local authorities or emergency personnel regarding local shelters or how to reach and stay with friends or family outside of the damaged area.
  • Continue to monitor weather conditions to make sure no other tornadoes are expected.

Tornado Clean-Up Tips
Clean up after a tornado can be daunting.  Check with local officials before you begin the clean up process to find out what resources are available to help residents in the area hit by the tornado.  Agencies such as FEMA, Environmental Protection Agency, the National Guard, the Red Cross, as well as a number of other volunteer resources are commonly available.

  • Assess the safety of the structure and the area for any hazards.
  • Wear protective clothing such as work gloves, safety glasses, and sturdy shoes. There will most likely be dangerous objects as you walk through the tornado aftermath, such as broken glass, screws, nails, etc.
  • The first difficult task is to sift through scattered debris to salvage what you can and sorting out what needs to be discarded.
  • DO NOT throw anything away until you have not only photographed it but also have contacted your insurance agent to clarify what items must be kept for the claims adjuster to see.
  • After getting the go ahead from your insurance company, make any needed temporary fixes to the roof, etc.
  • Watch out for scammers offering services that seem to be too good to be true.

Clean up after a disaster is draining and stressful, so take frequent breaks and drink plenty of fluids.

How To File An Insurance Claim
Filing an insurance claim after tornado damage takes a bit of work on your part.  Your insurance agent will advise you of how to move through the claims process. It is the homeowner’s responsibility to determine the amount of loss that will be submitted to the insurance company.  Some people opt to use a licensed public insurance adjuster, especially when damage is extensive and determining the claim amount to be submitted to the insurance agency can be difficult.  Claim adjusters typically charge a percentage of the settlement so each homeowner will have to weigh the pros and cons of considering a public insurance adjuster.

  • Take detailed photos of damage from the tornado and check with your insurance claims adjuster if there are any damaged items that the insurance company needs for claims purposes.
  • Make an inventory list of structural damage and property damage, including the estimated value of damaged items as well as expected cost of repair or replacement.  Spoiled food is also commonly eligible for coverage.
  • Contact your insurance agent or insurance adjuster immediately to let them know you will be filing a claim.  Be prepared to give them a rough estimate of damages incurred. Make sure to clarify exactly how long you have to submit your claim so you don’t miss the deadline.
  • If you are displaced from your home after the tornado and you have to stay in a hotel, be sure to keep receipts and records of your hotel stay, restaurant expense, and car rental.
  • Obtain estimates for repairs from licensed contractors.  Be cautious of individuals who are quick to take advantage of people after a disaster occurs.
  • File your claim.  Claims are typically processed according to severity.
  • Check with your insurance company about policies concerning temporary repairs so you can fix things that may cause further damage such as broken windows, etc.