Tornadoes are the most sudden, unpredictable and violent storms on earth. During the last century, more than 10,000 Americans died in tornadoes. 800 to 1,000 tornadoes are recorded each year in the U.S. — over 10 times more than in any other country. Whenever and wherever conditions are right, tornadoes are possible, but they are most common in the central plains of North America, east of the Rocky Mountains and west of the Appalachian Mountains. They occur mostly during the spring and summer; the tornado season comes early in the south and later in the north. They usually occur during the late afternoon and early evening. However, they have been known to occur in every state in the United States, on any day of the year, and at any hour. They also occur in many other parts of the world, including Australia, Europe, Africa, Asia, and South America. They can start in an empty field, or in a busy city, picking up homes, cars and businesses, leaving nothing but destruction in their path. Tornadoes come from energy released in a thunderstorm. As powerful as they are, tornadoes account for only a tiny fraction of the energy in a thunderstorm. What makes them dangerous is their energy is concentrated in a small area, perhaps only a hundred yards across. Science does not yet completely understand how part of a thunderstorm’s energy sometimes gets focused into something as small and potentially devastating as a tornado.
Can I locate a saferoom anywhere in my house?
Typically, saferooms should be located in a central, interior, ground-floor area of the home for additional protection as well as accessibility. The basement or garage of a home can also be used as a location for a saferoom.
If I have a basement do I really need a saferoom?
Some strong tornadoes have resulted in loss of the floor framing, collapse of basement walls, and death and injuries to individuals in the basement. What constitutes an acceptable level of protection is an individual decision. The basement is the safest place to seek shelter for homes without a saferoom. However, basements do not provide the same level of protection as a saferoom. Basements are a good location to install a shelter or build a saferoom but access for handicapped or physically challenged individuals may be limited.
Can I install a saferoom in my existing home?
A saferoom can be incorporated into the construction of a new home, or it can be retrofitted into an existing home. The saferoom can function year-round as a usable area, such as a bathroom, closet or utility room.
Can I install a saferoom myself?
This is not recommended due to the safety code requirements of saferoom installation that exceed standard building code requirements and an experienced, qualified installer is preferable.
Once installed do I need to have my saferoom inspected?
It is always important to get proper building permits and inspections for all construction. The builder or owner should ensure that the shelter is built according to the plans in FEMA 320 or to plans that, through testing and engineering have been determined to meet the National Performance Criteria for Tornado Shelters produced by FEMA. This will usually require additional quality control inspections by the saferoom installer or the contractor.
What is the difference between a tornado watch and a tornado warning?
A tornado watch is issued when there is a threat of tornado conditions in your area. You will still have time to take shelter. During a tornado watch, listen to a battery-operated radio or television for weather reports, and be prepared to move to shelter if you hear a tornado warning. A tornado warning is issued when a tornado has been sighted or indicated by weather radar. Remember move immediately to shelter if a tornado warning is issued in your area.
Here are additional things to consider when constructing or installing a saferoom:
• Safe rooms must be structurally isolated from the main structure of your home.
• Saferooms must be securely anchored in an adequate footing.
• Saferooms installed in or over a crawl space must have a separate foundation.
• Saferooms must have adequate ventilation.
• All components of saferooms, including walls, ceilings, and door assemblies, must be designed and tested to resist the specified wind forces and prevent perforation by windborne debris.
5 Deadliest Tornado “Superoutbreaks”
Date Location Deaths
1. March 18, 1925 Tri-State (Mo., Ill., Ind.) 689
2. May 6, 1840 Natchez, Miss. 317
3. May 27, 1896 St. Louis, Mo. 255
4. April 5, 1936 Tupelo, Miss. 216
5. April 6, 1936 Gainesville, Ga. 203
FUJITA-PEARSON TORNADO INTENSITY SCALE
MPH F-SCALE DAMAGE NAME
<73 F0 Damage to trees, signs & chimneys Gale Tornado
73—112 F1 Roofs damaged; cars rocked Moderate Tornado
113—157 F2 Roofs torn off; cars overturned Significant Tornado
158—206 F3 Forests uprooted; cars lifted Severe Tornado
207—260 F4 Homes destroyed; heavy objects fly Devastating Tornado
261—318 F5 Structures leveled; utter destruction Incredible Tornado
>319 F6 Theoretical; not expected on earth——
Dr. Fujita, Research Professor and Senior Meteorologist at Chicago University from 1955 until his death in 1998, originally created this scale in 1971 as a way of determining the strength of tornadoes from the damage caused. Like many of Dr. Fujita contributions, it was not widely accepted when first published. Two years later Dr. Fujita joined Dr. Pearson to publish a paper that added in factors related to the width and length of the tornado path, and called the scale the Fujita-Pearson Scale. It was after this work that the scale gained acceptance.
Scientists studying the tornadoes in Oklahoma on May 3, 1999 measured wind speeds of 318 miles per hour, the highest ever documented on Earth. This was accomplished by using two Doppler radar units mounted on separate trucks to study the tornadoes that ravaged the Oklahoma City area on May 3.