1. A natural disaster is a major adverse
event resulting from natural processes of
the Earth; examples
include firestorms, duststorms, floods,
hurricanes, tornadoes, volcanic
eruptions, earthquakes, tsunamis, storms,
and other geologic processes.

3. A natural disaster can cause loss of life or
damage property and typically leaves
some economic damage in its wake, the
severity of which depends on the affected
population's strength

8. A tornado is a violently rotating column of air that is in contact with both the
surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of
a cumulus cloud. It is often referred
toa twister, whirlwind or cyclone,[1] although the word cyclone is used
in meteorology to name a weather system with a low-pressure area in the center
around which, from an observer looking down toward the surface of the Earth,
winds blow counterclockwise in the Northern Hemisphere and clockwise in the
Southern.[2] Tornadoes come in many shapes and sizes, and they are often visible
in the form of a condensation funnel originating from the base of a
cumulonimbus cloud, with a cloud of rotating debris and dust beneath it. Most
tornadoes have wind speeds less than 180 km/h (110 mph), are about 80 m (250
feet) across, and travel several kilometers (a few miles) before dissipating.
The most extreme tornadoes can attain wind speeds of more than 480 km/h
(300 mph), are more than 3 km (2 miles) in diameter, and stay on the ground for
more than 100 km (dozens of miles).[3][4][5]

9. Types of Tornados
Various types of tornadoes include the multiple vortex
tornado, landspout, and waterspout. Waterspouts are characterized
by a spiraling funnel-shaped wind current, connecting to a large
cumulus or cumulonimbus cloud. They are generally classified as
non-supercellular tornadoes that develop over bodies of water, but
there is disagreement over whether to classify them as true
tornadoes. These spiraling columns of air frequently develop in
tropical areas close to the equator and are less common at high
latitudes.[6] Other tornado-like phenomena that exist in nature
include the gustnado, dust devil, fire whirl, and steam devil.

10. Areas Prone to Tornados
Tornadoes occur most frequently in North America (particularly in
central and southeastern regions of the United States colloquially
known as Tornado Alley; the US and Canada have by far the most
tornadoes of any countries in the world).[7] Tornados also occur
in South Africa, much of Europe (except Spain, most of the Alps,
Balkans, and northern Scandinavia), western and eastern Australia,
New Zealand, Bangladesh and adjacent eastern India, Japan,
Philippines, and southeastern South America (Uruguay and
Argentina).

11. After Effects of Tornados
1. Pollution – Large amount of Dust
2. Environmental Contamination
3. Injuries and Loss of Life
4. Household Hazardous Waste
5. Economic Loss
6. Destruction of Vegetation
7. Flash Flooding – destroys animal habitats as well
8. Effects on the Ecosystem
9. Asbestos Debris
10.Forest Fires

12. Precautions To Be Taken
1. PAY ATTENTION TO WARNINGS
2. MOVE TO THE BASEMENT QUICKLY
3. CROUCH LOW TO THE GROUND
4. GET SOMETHING UNDER STURDY
5. MONITOR STORM ALERTS
6. DO NOT STAY IN A MOBILE HOME
7. GO INSIDE
8. DON’T TRY TO OUTDRIVE THE TORNADO
9. AVOID OVERPASSES IF POSSIBLE
10. PREPARE AN EMERGENCY DISASTER KIT

13. If you are at home during a tornado:
Go to a windowless interior room on lowest level of your house. Go to a storm cellar or basement if your house has one. If
there is no basement, go to an inner hallway or a smaller inner room without windows, such as a bathroom or closet.
Get away from the windows.
Go to the center of the room. Stay away from corners because they tend to attract debris.
Get under a piece of sturdy furniture such as a workbench or heavy table or desk and hold on to it.
Use your arms to protect head and neck.
If you are in a mobile home, get out and find shelter elsewhere.
If you are at work or school during a tornado:
Go to the basement or to an inside hallway at the lowest level.
Avoid places with wide-span roofs such as auditoriums, cafeterias, large hallways, or shopping malls.
Get under a piece of sturdy furniture such as a workbench or heavy table or desk and hold on to it.
Use your arms to protect head and neck.
If you are outdoors during a tornado:
If possible, get inside a building.
If shelter is not available or there is no time to get indoors, lie in a ditch or low-lying area or crouch near a strong building.
Look out for flood waters which may also fill low areas.
Use your arms to protect head and neck.
If you are in a car during a tornado:
Never try to drive faster than a tornado in a car or truck. Tornadoes can change direction quickly and can lift up a car or truck
and toss it through the air.
Get out of the car immediately and take shelter in a nearby building.
If there is no time to get indoors, get out of the car and lie in a ditch or low-lying area away from the vehicle. Be aware of the
potential for flooding.

14. Case Study
The 1974 Super Outbreak – Tornado. –U.S.A
With 24 F4 and 6 F5 tornadoes, the 3 – 4 April 1974 outbreak has been the most violent tornado
outbreak ever recorded. Until 28 April 2011, it also was the largest outbreak for a 24-hour period.
148 confirmed tornadoes spread over 13 U.S. states from Alabama to Michigan and even New York
state, and Ontario, Canada. (Fig. 14.C1). With a death toll of 319, this outbreak was the deadliest
since the 1936 Tupelo-Gainesville tornado outbreak, and not surpassed until the 25 – 28 April 2011
outbreak. It was also one of the most costly, with an estimated $3.5 billion (2005 dollars) in damages.
Somewhat reminiscent of the weather situation leading into the 25 – 28 April 2011 outbreak (Fig.
14.36), on 1 April 1974, a powerful low-pressure system developed across the North American
Interior Plains. While moving into the Mississippi and Ohio Valley areas, a strong flow of very moist
mT air from the Gulf of Mexico moved in to intensify the storm. Cool, dry cP air pushed a cold front
on the western side. The jet stream had developed an southward excursion, with the returning leg
now blowing oblique along the cold front and across the Low. By 3 April, the central low pressure was
988 mbar. NOAA officials predicted a severe weather outbreak on 3 April but underestimated the
degree of severity. Earlier, a separate outbreak on 1 – 2 April, included three fatal tornadoes in
Kentucky, Alabama and Tennessee. An additional tornado was reported in Indiana early on 3 April.

15. On 3 April, severe weather watches were issued for the Great Lakes area. Snow was falling in parts of
the Midwest and heavy rain in Michigan and Ontario. By the afternoon severe thunderstorms formed in
Missouri that produced baseball-size hail. Numerous supercells and clusters of thunderstorms
developed in two zones, one across Illinois and the other across Tennessee, Alabama and northern
Georgia. The worst of the outbreaks shifted toward the Ohio Valley between 4:30 and 6:30 p.m.,
producing 4 F5 tornadoes. During the evening hours, outbreaks strengthened farther south across
Alabama, Tennessee and eastern Kentucky. Additional supercells developed across northern Indiana
and southern Michigan. Activity in the south moved toward the Appalachian during the night before the
final tornado occurred in the morning of 4 April, after 18 hours of continuous tornado activity. Later
studies found that long-lived single supercells spawned multiple tornadoes in succession. Apart from
the 30 F4 and F5 tornado, the Super Outbreak also counted 35 F3 tornadoes, 31 F2, 37 F1 and 15 F0.
An F5 striking Xenia, OH was the most deadly single tornado, killing 34 and destroying 1/4 of the city
and damaging another 1/4. A TV weather specialist in Dayton, OH alerted viewers in Montgomery and
Greene County (where Xenia is located) about a possible tornado, showing the characteristic hook echo
in the radar image, several minutes before the tornado struck. An amateur recording of the tornado that
is now on YouTube shows that it was actually composed of several vortices within the larger
circulation. Some point out that the Super Outbreak occurred after a strong La Niña but a clear
correlation between La Niñas and Super Outbreaks has yet to be established scientifically.

17. Bibliography
1. www.Wikipedia.org
2. www.geowiki.ucsd.edu
3. The New York Times
4. National geographic
5. www.nbc 12.com