COMMUNITY SAFETY

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TROPICAL CYCLONES

Introduction Cyclone Action Guide

INTRODUCTION

The Bureau of Meteorology provides a comprehensive weather service for all of Australia. Very high priority is given to providing warnings of events that may endanger life and property. The highest priority of all is given to tropical cyclones which pose a major threat to coastal areas in Queensland, Northern Territory and Western Australia.

Cyclone warning information can be obtained from the Bureau of Meteorology web site.

WHY IS A CYCLONE DANGEROUS ?

Cyclones produce extreme winds which 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 death by drowning. 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 which 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. 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 emphasised 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.

BACK TO TOP

CYCLONE ACTION GUIDE

BEFORE THE CYCLONE SEASON

• Check the roof and eaves of your home are secure.
• Trim tree branches well clear of your home.
• Preferably, fit window shutters or at least, metal screens.
• Clear your property of loose material that could blow about to cause injury or damage during extreme winds.
• Find out about 'Cyclone Watches and Warnings'.
• In case of a storm surge warning, know your nearest safe high ground and the best access route to it.
• Prepare an emergency kit containing:
  - a portable radio, torch and spare batteries;
  - stocks of fresh water and canned food ;
  - matches, fuel lamp, portable stove, cooking gear, utensils, can opener and waterproof bags; and
  - a first aid kit , manual and masking tape for windows.
  
• Keep a list of emergency phone numbers on display:

ON A CYCLONE WARNING

• Store loose items inside.
• Put wooden or plastic outdoor furniture in your pool.
• Fill bins and boats with water.
• Fuel your car and park it under solid cover.
• Close shutters or board-up or heavily tape all windows. Stay inside, with pets. Draw curtains and secure doors.
• Pack an evacuation kit of warm clothing, essential medications, valuables, papers, photos and mementos in waterproof bags, to be taken with your emergency kit.
• Listen to your local radio/TV for further information.

ON WARNING OF LOCAL EVACUATION

Based on predicted wind speeds and storm surge heights, evacuation may be necessary. Official advice will be given on local radio/TV regarding safe routes and when to move.

• Wear strong shoes (not thongs) and clothing for protection.
• Lock your home, switch off power, gas, water, and take your evacuation and emergency kits and mobile phone.
• If evacuating inland (out of town) take pets and leave early to avoid heavy traffic, flooding and wind hazards.
• If evacuating to a local shelter or higher ground, follow police and State/Territory Emergency Services directions.

WHEN THE CYCLONE STRIKES

• Disconnect all electrical appliances and turn off gas.
• Stay inside and shelter (well clear of windows) in the strongest part of the building, ie 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 (eg a water pipe).
• Listen to your portable radio for updates and advice.
• Beware the calm "eye". If the wind suddenly drops, don't assume the cyclone is over, violent winds will soon resume from the opposite direction. Wait for the official "all clear".
• If driving, stop - but well away from the sea and clear of trees, powerlines and watercourses. Stay in the vehicle.

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 fallen powerlines, damaged bridges, buildings and trees, and don't enter the flood waters.
• Heed all warnings and don't go sight-seeing.
• Don't make unnecessary telephone calls.

 

Community Safety