Previous Page

CYCLONE INFORMATION

Tropical cyclones produce extreme winds which may exceed 200 km/h. These winds can cause extensive property damage and cause airborne debris to become potentially lethal missiles. It is important to remember that the passage of the cyclone centre or "eye" will produce a temporary lull in the wind but that this will soon be replaced by extreme winds from another direction.

Cyclones also produce flood rains, which can cause further damage and raises the instance of possible drowning. Stay clear of all storm drains as flash flooding of these drains pose huge risks especially to children.


The phenomenal seas accompanying cyclones are dangerous both for vessels out at sea and those moored in harbours; serious erosion of the adjacent foreshore can also occur. 
Another marine phenomenon that can cause inundation of low-lying coastal areas is the storm surge. This is a raised dome of water about 60 to 80 km across and typically about 2 to 5m higher than the normal tide level. If the surge occurs at the same time as a high tide then the area inundated may be quite extensive.

Cyclone Severity Categories


An estimate of cyclone severity is now included in all tropical cyclone advices. The table on the right provides information concerning effects due to wind which are typical of cyclones in the various categories. Remember that the system is not designed to give an exact statement of conditions at individual locations but will give a general idea of the expected worst conditions. Categories of cyclone severity range from " 1 " for weak cyclones to "5" for the most severe cyclones. Accordingly, the risk of property and crop damage, shore erosion and danger to life increases from low for a category 1 to very high for a category 5 cyclone. Using this severity scale, communities will be able to assess the degree of cyclone threat and take appropriate action. It must be emphasized that the category refers to the severity in the zone of maximum winds and therefore the effects felt at individual locations may not be exactly as described in the accompanying table. 
Damage will vary from location to location depending upon factors such as: 
- how far you are from the zone of maximum winds 
- how exposed the location is 
- building standards 
- vegetation type 
- resultant flooding 
It should also be noted that the category does not refer to storm tides; if a storm tide is expected it will be mentioned separately in the cyclone warning. 

Categories


Category 1
Strongest gust less than 125 km/h
Typical effects (indicative only) - Negligible house damage. Damage to some crops, trees and caravans. Craft may drag moorings. 


Category 2
Strongest gust 125 - 170 km/h
Typical effects (indicative only) - Minor house damage. Significant damage to signs, trees and caravans. Heavy damage to some crops. Risk of power failure. Small craft may break moorings. 


Category 3 (e.g. Winifred)
Strongest gust 170 - 225 km/h
Typical effects (indicative only) - Some roof and structural damage. Some caravans destroyed. Power failure likely. 


Category 4 (e.g. Tracy) 
Strongest gust 225 - 280 km/h
Typical effects (indicative only) - Significant roofing loss and structural damage. Many caravans destroyed and blown away. Dangerous airborne debris. Widespread power failure. 


Category 5 (e.g. Orson)
Strongest gust More than 280 km/h
Typical effects (indicative only) - Extremely dangerous with widespread destruction. 


Cyclone Safety Precautions
An ounce of prevention ...

If you learn now, what to do when a cyclone threatens, you may well save the lives of everyone in your family. You cannot stop a cyclone. You cannot wait until one hits to learn what to do to survive. Make sure your whole family is prepared. Test their knowledge. 
Before the cyclone season
· Check your house is in good condition, particularly the roof. 
· Trim tree branches well clear of your house. 
· Clear property of loose sheet iron and other potential missiles. 
· Know your community disaster plan. 
· In case of a storm tide warning, know your nearest safe high ground and the best access route. 
· Prepare an EMERGENCY KIT (hold ready in home) 
1. Portable radio with fresh spare batteries. 
2. Torch, fuel lamp, candles, and matches. 
3. Water containers, tinned food, tin opener, self-contained cooking gear and essential spare clothes. 
4. First aid kit and essential medicines. 
5. Masking tape and plastic (garbage) bags. 

Upon a cyclone warning:-

· Listen constantly to radio/TV for further warnings and advice. 
· Batten down house, secure doors, board or tape windows. Paper pasted on windows with glue made from flour or starch is also effective. Store loose articles inside, place documents, photos, valuables and clothing in plastic bags. 
· Lock up pets, fill water containers, fuel car and place under cover. Then remain indoors 
· Prepare an EVACUATION KIT (carry in small bags). This consists of your emergency kit plus warm utility clothing (jeans, skivvies, etc.), personal essentials and valuables in plastic bags. 
On warning of a local evacuation 
· Lock up dwelling, switch off electricity, gas, water, etc. Take your evacuation kit. 
· Wear strong clothing to protect against cuts from debris. Wear strong footwear (not thongs) for protection. 
· Follow advice given. 
· Heed warnings--they are not given lightly! 
When the cyclone strikes
· Keep calm, stay inside--heed warnings and advice. 
· Shelter in strongest part of house--perhaps bathroom, internal toilet, or passage way. 
· If house starts to break up, protect yourself with mattress, rugs or blankets. Anchor yourself to strong fixture (such as water pipes) or get under a strong table or bed. 
· Beware the calm "eye": Don't assume the cyclone is over--if a calm period is due to the "eye", violent winds will soon resume from the opposite direction. 
After the cyclone 
· Don't go outside until advised officially that the cyclone has passed. 
· Listen to your radio. 
· If you had to evacuate, don't go home until advised. Use route recommended and stay calm. 
· Don't make unnecessary telephone calls. 
· Beware of fallen power lines, damaged buildings and trees, and flooded water courses. 
· Don't go sight-seeing. 
· Above all, DON'T IGNORE WARNINGS! 

Extract from the Bureau of Meteorology http://www.bom.gov.au

The Reef Links

  The Great Barrier Reef - Where reefs occur

Box jelly fish - Blue Ringed Octopus - Sting rays - Lion Fish - Cone Shells

The Rainforest Links

Cyclone Info - Rainforest intro - animal safety -  Home

Tourism Info Links

Visitor Info Main - Atherton Tablelands and waterfalls district - Cairns - Crater lakes district - Kuranda - Mission Beach - Accommodation (graphical version) 

Other Links

Tropical cyclone information 

 

Links to the full graphical version of the site

 

Home -  Accommodation - Maps - Rainforest Info - Reef info  Tours -  Site Seeing  

Visitor Info - Weather & Currency Converter  - Australia Celebrates 1901 - 2001 - Site Map   Tours 

©2001 - 2003 BarrierReefAustralia.com

this page is printer friendly! [tropical cyclone information]