Cyclone Aware 2C.1
To introduce students to the Engage Cyclone Aware causes and effects of tropical cyclones in Western Australia.
A tropical cyclone is a natural hazard that brings with it damaging winds, heavy rainfall, flooding and storm surge. Some communities who do not experience a direct tropical cyclone impact can still experience a disaster from widespread flooding. Western Australia experiences tropical cyclones every year, which normally affect the coast in the Kimberley, Pilbara and Midwest Gascoyne regions but they can also affect inland parts of northern WA and can travel down the coast and threaten communities further south. Tropical cyclones form in the warm tropical waters north of Australia where they begin as a cluster of thunderstorms. If conditions are right more thunderstorms form, winds increase and the system grows and begins to spin in a clockwise direction. Tropical cyclones, also known as hurricanes and typhoons in other parts of the world, are the most powerful and destructive weather system on the planet and can affect thousands of square kilometres. One severe tropical cyclone can release energy equal to two hundred times the world capacity to generate electricity. Meteorologists generally expect about five tropical cyclones to form in waters off the northwest coast of WA each season between November and April, with the State’s northwest the most cyclone prone part of Australia’s coastline. On average two of these cyclones may cross the northwest coast, with one crossing as a severe tropical cyclone. Every season is different with the number of tropical cyclones varying from season to season. The Department of Fire and Emergency Services (DFES) in Western Australia is responsible for planning, preparedness and response around tropical cyclones. Wind speed is used to measure the severity of a tropical cyclone. Average winds must be at least 63 kilometres per hour near the centre for a system to be called a cyclone. There are five categories of cyclone, with Category 5 being the strongest category. (Please note: Further lesson plans on flood can be found as part of the Natural Hazards online program). Objective: At the end of the lesson students should understand that tropical cyclones are natural weather phenomena which can be hazardous to people and communities as they impact the Western Australian coast. Cyclone Aware: Tropical Cyclones • Students view tropical cyclone video (Cyclone in Action Part 1) and brainstorm tropical cyclone terminology to develop a mind map. (Cyclone Aware 2C.2) • Ask students to read Tropical Cyclone Facts (Cyclone Aware 2C.3), adding further information to their mind map. Additional information can be added to this map as students progress through each tropical cyclone lesson. • Students view tropical cyclone video (Cyclone in Action Part 2) and complete question chart, What do you know about Tropical Cyclones? (Cyclone Aware 2C.4) Discuss with students: do (or can) cyclones occur where you live? Are you or your community at risk of tropical cyclone? • As a class, discuss the cyclone category chart and the damage that tropical cyclones can bring. Students examine the ‘typical wind effects’ and draw a picture depicting the level of cyclone damage that could occur within each Tropical Cyclone Category. (Cyclone Aware 2C.5) • Students visit the Bureau of Meteorology (BoM) website www.bom.gov.au/cyclone/history/wa/ Previous Tropical Cyclones in Western Australia. Study a town impacted by a tropical cyclone. (Cyclone Aware 2C.6) • Use the image Tropical Cyclone Fay to draw and label the main features of cyclone formation (such as the eye, eye wall, main cloud bands and arrows showing the rotation of the cyclone). (Cyclone Aware 2C.7)
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Cyclone Aware 2C.2
Tropical Cyclone Mind Map – Complete the mind map using these subheadings: emergency services, preparation, communication, recovery.
Add related words to complete the mind map.
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Cyclone Aware 2C.3
Tropical Cyclone Fact Sheet
In Western Australia the cyclone season starts in November and continues through to April. During this time northern and north western coastal regions of Western Australia are at risk of being impacted by cyclones.
Experiencing a tropical cyclone can be frightening and traumatic as they can cause injury, loss of life, major structural damage to communities, disruption of utility and telecommunication services, and turn debris into dangerous missiles.
Australia’s most powerful and destructive tropical cyclone in recent years collided with Queensland’s Mission Beach on 3 February, 2011.Estimated to have reached wind speeds of 295 kilometres per hour, Severe Tropical Cyclone Yasi a Category 5 cyclone, caused widespread damage.
Many of the most powerful tropical cyclones often don't make it to land at all, but complete their life cycle over water, weakening below cyclone intensity when conditions are no longer favourable. The average life of most cyclones is one week.
Cyclones spin because the Earth is spinning. This is called the Coriolis effect. The direction of a tropical cyclone’s spin depends on whether it forms in the top half of Earth or the bottom half. All tropical cyclones in the Northern Hemisphere (above the Equator) rotate in an anti-clockwise direction and clockwise in the Southern Hemisphere (below the Equator).
When sustained winds reach around 63km/h more than half way around the system centre, we begin to see an eye wall and spiral rain bands forming, the Bureau of Meteorology will name the system as a tropical cyclone
The eye of a cyclone can range from 3.2 kilometres in diameter to over 320 kilometres but they average around 50 kilometres. The winds are strongest surrounding the eye.
In 120 kilometres per hour winds it is difficult to walk forward without losing your balance. Once winds get to about 170 kilometres per hour, standing without holding onto something is nearly impossible. The wind will blow you back and/or down and it is nearly impossible to keep your eyes open...the noise is deafening. Once winds get to about 220 kilometres per hour, the wind is far too strong to stand in, and the noise is so loud that even when you shout as loud as you can into the wind you cannot hear anything except the roar of the wind.
Once a cyclone has formed, it is given a name to help meteorologists issue forecasts and warnings to the people who will be affected by the cyclones. The Bureau of Meteorology has a list of 104 names that are used for naming tropical cyclones than form in the Australian Region. Tropical Cyclone names alternate male and female names.
The word "cyclone" comes from the Greek word “Cyclops” – giants, with only one eye.
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Cyclone Aware 2C.4
What do you know about tropical cyclones? – View the video footage (Cyclone 2) and complete the following table:
TROPICAL CYCLONES
How does a cyclone look, Physical sound, feel?
How does a cyclone Cause and occur?
Effect What does it do?
Where and when do Environmental cyclones occur?
How often do cyclones Other happen in Western
Questions Australia?
What is the most dangerous tropical cyclone to occur in Western Australia? Could it happen where you live? What do you do in a
tropical cyclone emergency?
What? Facts I already Where? know about tropical How? cyclones Why? When?
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Cyclone Aware 2C.5
Tropical Cyclone Damage – Discuss the Cyclone Category Chart below and the damage that tropical cyclones can bring.
Category Strongest Gust (km/h) Typical Wind Effects
Negligible house damage. Less than 125 km/h Damage to some crops, trees and 1 Gales caravans. Boats and craft may drag moorings.
Minor house damage. Significant damage to signs, trees 125 – 164 km/h and caravans. 2 Destructive winds Heavy damage to some crops. Risk of power failure. Small craft may break moorings.
Some roof and structural damage. 165 – 224 km/h Some caravans destroyed and blown 3 Very destructive winds away. Power failure likely.
Significant roofing loss and structural damage. 225 – 279 km/h Many caravans are destroyed and 4 Very destructive winds blown away. Dangerous airborne debris. Widespread power failure. More than 280 km/h Extremely dangerous with Extremely destructive 5 widespread destruction. winds
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Cyclone Aware 2C.5
Tropical Cyclone Damage – Write down the strongest wind gust for each Tropical Cyclone Category and under the heading Typical Wind Effects draw pictures that depict the level of cyclone damage that could occur within each Tropical Cyclone Category.
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Cyclone Aware 2C.6
Research a Tropical Cyclone in Western Australia – Visit the BoM website: www.bom.gov.au/cyclone/history/wa/
Scroll down the page to the heading, Tropical Cyclone Names. Choose a cyclone from the following list and complete the table with the information you find on the BoM website:
T.C. George T.C. Fay T.C. Monty T.C. Clare T.C. Joan T.C. Bobby T.C. Rosita T.C. Olivia
WESTERN AUSTRALIA TROPICAL CYCLONES
Name of cyclone
Name of town/s affected
Date of impact
What category did it cross the coast as?
Length of cyclone activity
(days/weeks)
Highest wind speed category recorded during its tracking
Damage caused by wind, rain and storm surge
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Cyclone Aware 2C.7
Tropical Cyclone Fay – Draw a circle and arrow to highlight each of the main features of cyclone formation with the image of Tropical Cyclone Fay below. The main features of cyclone formation:
Arrows to show the Eye Eye Wall Main Cloud Bands direction the cyclone is spinning.
Tropical Cyclone Fay Image courtesy of NASA
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Teacher Notes 2C
Answers: Mind Map (Cyclone Aware 2C.2)
Emergency services, hazard agency, DFES, BoM, SES, St John’s Ambulance
Weather conditions, floods, rain, winds, storm surge, severe storm, gales
Communication, SEWS, tracking, radar, satellites, alerts, warnings, radio, websites
Preparation, emergency kit, relocation kit, evacuation, relocation, shelter, property
Recovery, clean-up, rebuilding
People, community, welfare groups, Red Cross
Accept other relevant terms
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Teacher Notes 2C
Tropical Cyclone Fay (Cyclone Aware 2C.7)
In the southern hemisphere cyclones rotate in a clockwise direction.
Tropical Cyclone Fay Image courtesy of NASA
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