Tornados
What is a tornado?
Tornadoes are nature’s most violent storms.
à 
à 
à
First, heat rises and a storm begins.
à 
à 
Then, when there is air from two directions a spiral begins.
Finally, a funnel drops and a tornado is created.
Where do tornadoes occur?
The geography of the central part of the United States, known as the Great Plains, is the best place to form tornadoes. More than 500 tornadoes occur in this area every year and it is called "Tornado Alley".
How much damage can tornadoes do?
You calculate the danger of a tornado on a scale of F0 to F5. F5 is the most dangerous.
Fujita Scale of Tornado Intensity
|
SCALE |
WIND SPEED |
POSSIBLE DAMAGE |
|
F0 |
64-115 km/h |
Light damage: Branches broken off trees; minor roof damage |
|
F1 |
116-180 km/h |
Moderate damage: Trees snapped; mobile home pushed off foundations; roofs damaged |
|
F2 |
181-252 km/h |
Considerable damage: Mobile homes demolished; trees uprooted; strong built homes unroofed |
|
F3 |
253-331 km/h |
Severe damage: Trains overturned; cars lifted off the ground; strong built homes have outside walls blown away |
|
F4 |
332-418 km/h |
Devastating damage: Houses leveled leaving piles of debris; cars thrown 300 yards or more in the air |
|
F5 |
419-511 km/h |
Incredible damage |
When
do tornadoes occur?
Tornado season is from March through May. Peak times for tornadoes
in the northern states are during the summer. A few southern states have a
second peak time for tornado outbreaks in the fall. Tornadoes are most likely
to occur between 3 p.m. and 9 p.m.
South United States à March – May and September- November
North United States à June –September
Look at tornado videos on this site