cyclone definition, tropical and local storms, causes, effects, precautions and mitigation of cyclones

1. CYCLONES
BY P. HARIKA

2. CONTENTS
• Tropical cyclones and local storms
• Destruction by tropical cyclones and local storms
• Effects
• Causes
• Perception
• Mitigation

3. CYCLONE
• It is caused by a combination of strong winds driving water
onshore and the lower atmospheric pressure in a tropical
cyclone.

4. TROPICAL CYCLONES
• Tropical cyclone, also called typhoon or hurricane, an
intense circular storm that originates over warm tropical
oceans and is characterized by low atmospheric pressure,
high winds and heavy rain.

5. DIFFERENT NAMES
• Western North – hurricanes
• western North Pacific – typhoons
• Bay of Bengal and Arabian Sea – cyclones
• Western South Pacific and southeast India Ocean - severe
tropical cyclones
• Southwest India Ocean - tropical cyclones

6. OCCURRENCE
• western North Pacific region - May to November
• Americas/Caribbean hurricane - June 1 to November 30
• South Pacific and Australia - November to April
• Bay of Bengal and Arabian Sea - April to June and September
to November
• East Coast of Africa - November to April

7. LOCAL STORM
• Tornado
• Hailstorm

8. THUNDERSTORM

9. EFFECTS
At sea:
• Shipping
Upon landfall:
• Strong winds
• Storm surge
• Heavy rainfall

10. CAUSES
There’s no single cause which results in a cyclone, but it’s a chain of
event’s that finally end’s up as a Cyclone.
Let’s analyse those chain of event’s one by one :
• A large warm and still ocean area with temperature above 27ºC
formed. Due to this, the air above these area get heated and
therefore it rises up.
• The risen air, would make vacancy of air in that region i.e low
pressure area.
• The air around rushes to fill that vacant area.

11. • The risen air would also carry a great amount moisture, i.e the water
evaporated and turned into vapour is also carried with air.
• This moist air on reaching some height, cools down, condensation
happens and clouds are formed.
• The above said processes continues, and eventually the clouds
became heavy.
• The resulting condensation would release latent heat, that would
provide the cyclone with more energy. (Heat’s the water again)
• The wind that arrives from vast areas to this area of low pressure,
would get deflected and eventually twists due to Coriolis effect.
• The cyclone is formed.

13. PRECAUTIONS
Before the cyclone season
• Check with your local council or your building control authority to see
if your home has been built to cyclone standards.
• Check that the walls, roof and eaves of your home are secure.
• Trim treetops and branches well clear of your home (get council
permission).
• Preferably fit shutters, or at least metal screens, to all glass areas.
• Clear your property of loose material that could blow about and
possibly cause injury or damage during extreme winds.

14. When a cyclone watch is issued
• Re-check your property for any loose material and tie down (or fill
with water) all large, relatively light items such as boats and rubbish
bins.
• Fill vehicles' fuel tanks. Check your emergency kit and fill water
containers.
• Ensure household members know which is the strongest part of the
house and what to do in the event of a cyclone warning or an
evacuation.
• Tune to your local radio/TV for further information and warnings.
• Check that neighbours are aware of the situation and are preparing.

15. On warning of local evacuation
• Wear strong shoes (not thongs) and tough clothing for protection.
• Lock doors; turn off power, gas, and water; take your evacuation and
emergency kits.
• If evacuating inland (out of town), take pets and leave early to avoid
heavy traffic, flooding and wind hazards.
• If evacuating to a public shelter or higher location, follow police and
State/Territory Emergency Services directions.
• If going to a public shelter, take bedding needs and books or games
for children.

16. When the cyclone strikes
• Disconnect all electrical appliances. Listen to your battery radio for
updates.
• Stay inside and shelter {well clear of windows) in the strongest part of
the building,
i.e. cellar, internal hallway or bathroom. Keep evacuation and
emergency kits with you.
• If the building starts to break up, protect yourself with mattresses,
rugs or blankets under a
strong table or bench or hold onto a solid fixture, e.g. a water pipe.
• Beware the calm 'eye'. If the wind drops, don't assume the cyclone is
over; violent winds
will soon resume from another direction. Wait for the official 'all
clear'.

17. After the cyclone
• Don't go outside until officially advised it is safe.
• Check for gas leaks. Don't use electric appliances if wet.
• Listen to local radio for official warnings and advice.
• If you have to evacuate, or did so earlier, don't return until advised.
Use a recommended route and don't rush.
• Beware of damaged power lines, bridges, buildings, trees, and don't
enter floodwaters.
• Heed all warnings and don't go sightseeing. Check/help neighbours
instead.

18. MITIGATION
Actions Before: Increase Knowledge, Determine Risk, Safeguard, Plan
• Determine the disaster risks in your locale and the hazards that accompany them.
• Increase your knowledge about the emergency warning signals and alert notifications
used in your community.
• Instruct family members how to shut off water, gas and electricity to your house.
• Make the necessary property preparations to reduce the damage from the hazard.
• Acquire a backup generator in case of a prolonged power failure.
• Check into insurance (property, health, life, and hazard type).
• Make the necessary financial arrangements in case of a sudden evacuation and power
outage that shuts down local ATMs and banks.
• Organize important documents and records and store them in a portable lock box or
safe-deposit box.

19. Actions During: Safety Basics, Evacuation, Shelter in Place
• Hurricane Watch (conditions within 24-36 hours):
• Listen to battery-operated radio for progress reports; check emergency supplies.
• Secure buildings by closing and boarding up windows .
• Remove outside antennas.
• Turn refrigerator and freezer to coldest settings .
• Store drinking water in clean bathtubs, jugs, and bottles.
• Moor boat securely or move to a designated safe place; anchor trailer to ground.
• Review evacuation plan.
• Hurricane Warning (conditions expected in 24 hours or less):
• Listen to radio for instructions.
• Tie down mobile home and evacuate immediately.
• Store valuables in waterproof container
• Avoid elevators.

20. Actions After: Get Disaster Relief, Clean-up, Salvage
• Stay tuned to radio for information, returning home only when authorities
advise it is safe to do so.
• Help injured or trapped persons and give first aid where appropriate.
• Avoid loose or dangling power lines and report them to the power
company or fire department.
• Beware of snakes, insects, and animals driven to higher ground by flood
water.
• Open windows and doors to ventilate and dry your home.
• Check refrigerated foods for spoilage.
• Take pictures of the damage for insurance claims.
• Drive only if necessary and avoid flooded roads and washed-out bridges.
• Use telephones only for emergency calls.