Narelle is expected to become a category five cyclone — what does that mean?
Cyclone Narelle is expected to strengthen into a category five cyclone before making landfall. (Supplied: BOM)
Cyclone Narelle has formed in the Coral Sea and is expected to intensify into a category five cyclone before it makes landfall over the Far North Queensland coast later this week.
It's the third severe weather system to threaten parts of Queensland in less than two months.
But what exactly defines a category five cyclone and how rare are they?
What is a category five cyclone?
The severity of tropical cyclones are ranked in categories from 1 (the weakest) to 5 (the strongest).
Those categories are defined based on the cyclone's maximum mean wind speed.
The Bureau of Meteorology defines a Category 5 cyclone as one that is:
- Extremely dangerous with widespread destruction of buildings and vegetation
- Has a maximum mean wind speed greater than 200 km/h
- Has a typical strongest gust greater than 279 km/h
It is not yet clear whether the system may weaken to a category four cyclone before making landfall north of Cooktown.
What are the impacts?
Regardless of category or size, tropical cyclones can be dangerous.
The three major impacts of a tropical cyclone are wind, rain and storm surges.
Tropical cyclones bring gale force winds that can cause extensive damage to property and turn airborne debris into potentially lethal missiles.
When the eye of a cyclone passes over a location, there will be a temporary lull in wind speed which will soon be replaced by destructive winds from another direction.
Tropical cyclones can bring extensive flooding through heavy rainfall that can persist even as the cyclone moves inland and begins to weaken.
Tropical cyclones can cause the sea to rise well above the highest tide levels. This is caused by strong onshore winds and reduced atmospheric pressure.
The bureau says storm surges have the potential to be the most dangerous hazard associated with tropical cyclones.
Extreme storm surges can swamp low-lying areas and drive destructive water flow inland, sometimes for several kilometres.
The timing of storm surges can also be difficult to predict due to the erratic nature of tropical cyclone paths.
When did the last category five cyclone hit Australia?
The last tropical cyclone to make landfall as a category five system was Tropical Cyclone Ilsa, which crossed Western Australia's north coast just before midnight on April 13, 2023.
The powerful cyclone recorded peak wind gusts of up to 289 km/h.
In fact, the gusts became so powerful they broke the Bureau of Meteorology's equipment and set an Australian record with a 10-minute sustained wind speed of 218 km/h.
The system was downgraded to a category three about four hours after it made landfall between De Grey and Pardoo Roadhouse — about 120 kilometres north of Port Hedland.
The last category five cyclone to make landfall in Queensland was Tropical Cyclone Marcia, which crossed the coast near Shoalwater Bay on February 20, 2015.
Marcia caused significant damage to almost 2,000 properties around Yeppoon and Rockhampton.
Nearly 40,000 insurance claims were lodged and central Queensland farmers were left with an estimated $200 million damage bill.
What should I do to prepare?
Loading...There are lots of things you can do to keep you and your family safe in a cyclone.
Fill up your car
Make sure to fill up your car so you are ready to evacuate if needed.
Park it in a sheltered area away from trees and powerlines, which may fall in strong winds.
If a flood is approaching, be prepared to leave your home quickly and early, and check for road closures before you leave.
Secure caravans and trailers
If possible, park caravans and trailers in a sheltered area.
Otherwise, park them with the narrow end facing the wind and away from trees and powerlines.
A strong net cast over the roof, passing the full length and firmly fixed in the ground, is the most secure way to tie down a caravan or trailer.
Apply the brakes and chock the wheels.
Remember to take down any awnings.
Know your insurance details
Check your insurance policy has enough cover for your home and contents.
Keep the contact details of your insurer and your policy number handy — either print it out or take a screenshot of your details on your phone.
Secure loose outdoor items
Keep your yard clear of leaves and rubbish, and remove vegetation from the fence line.
Look around for loose items like garden furniture, trampolines or toys.
Either move them inside or secure them.
Prepare your pets
Small pets
If possible, bring your pets indoors and make sure you have enough food and water as well as supplies to clean up any messes.
The Queensland government's severe weather advice recommends having supplies to last at least five days.
Plan in advance what you will do with your pets if you have to evacuate.
Keep in mind that pets may not be allowed in some evacuation shelters, unless they are a service animal.
Check if family and friends who live outside your area would be able to take care of them if you need to evacuate.
Large pets and livestock
If possible, move livestock, horses and other animals to a safe paddock with high ground or solid shelter.
Consider opening internal property gates to allow animals to move between paddocks to dry ground.
Ensure animals are supplied with enough water and supplementary feed to last at least five days.
Brace for power outages
Prolonged blackouts can happen in cyclone systems, so be prepared for long periods without electricity.
Have candles, matches and torch with batteries ready in case the power goes out.
If you need to light a room with just a torch, rest it on a table or bench and point it up towards the ceiling to maximise the amount of light.
Never use a power generator inside because it produces dangerous levels of carbon monoxide that can kill people.
Fully charge your phone and other communication devices — if you have spare power banks, ensure they're fully charged as well.
Have a full supply of gas for your barbecue or gas cooker to prepare meals.
If your power goes out and you're preparing meals, use up your most perishable items first — save the items that don't go off at room temperature for later.
Make sure you have a can opener if you've got tins without ring-pull openings.
The general advice is to discard perishable food after the power has been out for more than four hours.
So make sure you have non-perishable food on hand to keep you going just in case.
If the power does go out, minimise how often you're opening and closing the fridge or freezer to keep the cool in for as long as possible.
If power has been out for two hours, move items out of the fridge and store them in the freezer, if you have room, the Food Safety Information Council says.
"If your freezer is efficient, and its door seals are in good condition, it can maintain foods in a frozen state for between one and two-and-a-half days," the council says.
It says things like salted butter, margarine and hard cheeses will remain safe at room temperature.
Look after your roof, gutters and pipes
Check the condition of your roof and make any needed repairs.
Clean your gutters and downpipes of leaves and any other blockages.
Check with your local council about cutting away any tree branches hanging over your roof.
Contact your local power distributor if you spot any trees overhanging power lines.
Know how to use sandbags
While sandbags won't completely stop flood waters from approaching your property, they can reduce how much enters your home.
You can find a list of where to get sandbags below.
The Queensland government advises most standard homes and buildings can be protected with less than 25 sandbags.
The advice also states it's not always necessary to build a sandbag wall around your whole building to provide adequate protection.
"This may only be necessary if it is on stumps or constructed of materials such as timber or fibro sheeting," Get Ready Queensland's page on sandbags reads.
Place on a layer of plastic sheeting and build them up like brickwork.
Stagger the rows so joins don't line up and make sure the empty part of the bag is covered by the next bag.
Sandbags should be placed over drains to prevent back-flow of grey water.
Secure your windows
Repair any broken seals around windows and fix any rust, loose fittings and rotting timber.
If your home is in the expected path of the cyclone, board up any exposed windows, doors and seep holes if possible.
You can also tape plastic sheeting to the inside of windows to help keep wind and rain out of your home.
Know how to turn off your utilities
Be prepared to disconnect your utilities, such as gas, electricity, solar and water services if instructed.
So make a note of where those switches are now — and figure out how to switch them off if need be.
Some utility switches's labels might be difficult to read if they're quite old, so take a photo of what the switches look like while they're on so you know what it looks like.
Think about your water supply
Fill buckets or your bath with clean water in case access to the main supply is disrupted.
Fill up any water bottles you have in the house and keep them in the freezer if you have room — they will come in handy for keeping things cool if the power cuts out.
How do I stay up to date with the cyclone?
You can head to the ABC Emergency website for all updates, including a map of all warnings.
We'll be live blogging as the cyclone tracks closer to the coast, so stay across the ABC News website.
ABC Emergency will broadcast regular warnings on ABC Radio, which you can stream on the ABC Listen App.
Here are the radio frequencies for local stations:
- Cairns and surrounds: 801 AM and 106.7 FM
- Cairns North: 95.5 FM
- Coen: 105.9 FM
- Cooktown: 105.7 FM
- Lakeland: 106.1 FM
- Laura: 106.1 FM
- Mossman and surrounds (including Daintree, Port Douglas): 639 AM
- Weipa: 1044 AM
ABC Far North is also available on Channel 211 through the VAST satellite service.
You can also keep across the latest warnings from the Bureau of Meteorology on their website.
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