Air Force
10-31-2004, 02:08 AM
Mother Nature expresses herself in some twisted ways. Just consider tornadoes: These violent storms characterized by spinning, funnel-shaped clouds can have sustained winds in excess of 250 miles per hour. And when they touch ground, they can leave a mile wide trail of damaged property and leveled trees as much as 50 miles long.
Basic Facts
In the interest of "knowing the enemy," check out this roundup of the what, where, how and why of these fascinating storms.
* Tornadoes are formed in thunderstorms when a layer of cool air overrides warm air. This forces the warmer air to rise very rapidly and pushes storm winds that normally spin horizontally into a vertical position.
* Tornadoes can form in any part of the country, but most develop east of the Rocky Mountains. Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, South Dakota and Texas are considered tornado danger zones and homes in these states are most at risk.
* While spring and summer are peak tornado season, the storms can form at any time of year. In some states they are common in the fall.
* Tornadoes can arrive with little warning. Listen to weather reports and notice if you are near the storm's path. Pay particularly close attention to watches and warnings. A tornado watch is issued when conditions are suitable for tornado formation. A tornado warning is released when a tornado has been spotted or indicated on radar.
* A tornado may not be visible as a funnel cloud. Rain or clouds can even hide them. Luckily, there are other danger signs to look for. An approaching cloud of debris or cloud "wall" may be a tornado. Strong winds, lightning and large hail often precede the storms, but the air around the funnel may be very still. The "roar" of an approaching tornado's winds is compared to the sound of a freight train. And they often appear on the backside of a thunderstorm. You may even see clear skies behind a tornado.
How Bad Is Bad?
Tornadoes are measured on the Fujita-Pearson Scale and assigned F-numbers that correspond with their strength. For a detailed breakdown, see below.
F Number Wind Speed Damage Potential
F-0 40 to 72 mph Can damage chimneys and break tree branches.
F-1 73 to 112 mph Can overturn mobile homes.
F-2 113 to 157 mph Can demolish mobile homes and uproot trees.
F-3 158 to 205 mph Can throw automobiles and tear up roofs and walls.
F-4 207 to 260 mph Can level well-constructed building walls.
F-5 261 to 318 mph Can throw cars 100 meters and lift houses off foundations.
Take Cover
Here's how to take care when you're in the path of a tornado.
* If a tornado strikes while you are at home, immediately go to a windowless interior room, the basement, your storm cellar or to the lowest level of the house.
* Leave mobile homes and lie in a ditch or low-lying area well away from the unit.
* Stay away from windows. Most tornado damage results from high winds and flying debris.
* Go to the center of the room. Debris collects in corners.
* Get under a heavy piece of furniture (table, workbench or desk) and hold on to the legs.
* Cover your head and neck with your arms.
Basic Facts
In the interest of "knowing the enemy," check out this roundup of the what, where, how and why of these fascinating storms.
* Tornadoes are formed in thunderstorms when a layer of cool air overrides warm air. This forces the warmer air to rise very rapidly and pushes storm winds that normally spin horizontally into a vertical position.
* Tornadoes can form in any part of the country, but most develop east of the Rocky Mountains. Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, South Dakota and Texas are considered tornado danger zones and homes in these states are most at risk.
* While spring and summer are peak tornado season, the storms can form at any time of year. In some states they are common in the fall.
* Tornadoes can arrive with little warning. Listen to weather reports and notice if you are near the storm's path. Pay particularly close attention to watches and warnings. A tornado watch is issued when conditions are suitable for tornado formation. A tornado warning is released when a tornado has been spotted or indicated on radar.
* A tornado may not be visible as a funnel cloud. Rain or clouds can even hide them. Luckily, there are other danger signs to look for. An approaching cloud of debris or cloud "wall" may be a tornado. Strong winds, lightning and large hail often precede the storms, but the air around the funnel may be very still. The "roar" of an approaching tornado's winds is compared to the sound of a freight train. And they often appear on the backside of a thunderstorm. You may even see clear skies behind a tornado.
How Bad Is Bad?
Tornadoes are measured on the Fujita-Pearson Scale and assigned F-numbers that correspond with their strength. For a detailed breakdown, see below.
F Number Wind Speed Damage Potential
F-0 40 to 72 mph Can damage chimneys and break tree branches.
F-1 73 to 112 mph Can overturn mobile homes.
F-2 113 to 157 mph Can demolish mobile homes and uproot trees.
F-3 158 to 205 mph Can throw automobiles and tear up roofs and walls.
F-4 207 to 260 mph Can level well-constructed building walls.
F-5 261 to 318 mph Can throw cars 100 meters and lift houses off foundations.
Take Cover
Here's how to take care when you're in the path of a tornado.
* If a tornado strikes while you are at home, immediately go to a windowless interior room, the basement, your storm cellar or to the lowest level of the house.
* Leave mobile homes and lie in a ditch or low-lying area well away from the unit.
* Stay away from windows. Most tornado damage results from high winds and flying debris.
* Go to the center of the room. Debris collects in corners.
* Get under a heavy piece of furniture (table, workbench or desk) and hold on to the legs.
* Cover your head and neck with your arms.