Tropical cyclones are extremely dynamic and therefore dangerous hazards. Threats to life and property arise from strong and damaging winds, widespread heavy rain and flooding, as well as storm surges. This is especially so for a category 5 system (the highest and potentially most destructive cyclones). The impacts of tropical cyclones are directly dependent on, and made worse by, the vulnerability of affected populations – that is, the pre-existing social and economic conditions of people in the area.

For example, people with low incomes or renters may be living in poorer quality housing more likely to be destroyed or severely damaged, people who do not speak English may have less access to up-to-date information or capacity to comprehend warnings, marginalised people might be more socially isolated and have fewer friends, family or other community networks to draw on for assistance, or people without insurance could face significant financial hardship into the future. 

Immediate management of the disaster will focus on trying to keep people safe, and everyone in affected areas should follow the advice of local authorities such as DFES.

Longer term response will involve damage assessment, likely large scale clean-up efforts, and eventually rebuilding, and should also include adequate mental health support for people impacted by the events. Longer term recovery should not only focus on rebuilding damaged homes and infrastructure but on building community resilience and addressing vulnerabilities to help mitigate losses during future hazards, which are only set to increase in frequency and severity under current climate change patterns.

Climate change and extreme weather events are increasing, making resilient design more critical than ever to ensure a building maintains its integrity.

In extreme wind events, roofs are often the first point of failure due to uplift forces, especially when anchorage is inadequate. Weakness in windows and doors can lead to dangerous internal pressurisation, while poor roof-to-wall connections reduce overall wind resistance.

Aerodynamic roof and wall designs help reduce wind pressure. Ensuring continuous load paths from the roof to the foundation is crucial for distributing wind forces effectively.

Following design guidelines tailored to high-wind regions (such as wind regions C and D) is essential. The use of impact-resistant materials for windows and doors, as well as certified C4 wind-rated cladding, improves durability. Wind tunnel testing, combined with finite element (FE) and computational fluid dynamics (CFD) simulations, can provide valuable insights for design improvements.

Severe Tropical Cyclone Zelia is currently moving toward the Pilbara coast with landfall expected just east of Port Hedland this afternoon. Zelia is a very intense system with estimated maximum mean winds of 205 km/h and gusts to 285 km/h. While its size is relatively compact with damaging winds extending approximately 120 km from its centre, Zelia’s likely impacts extend well beyond its winds to include the storm tide and locally intense rainfall.

Zelia formed as a tropical disturbance on 7 February, tracking west- to south-west until it was upgraded to a category 1 tropical cyclone and named Zelia by the Bureau of Meteorology on 11 February. It continued to intensify, reaching category 2 by the next day. On the evening of 12 February, Zelia slowed down and began to rapidly intensify, reaching Category 5 by the morning of 13 February. It began to track slowly south-east, and then south toward Port Hedland. As Zelia moved toward the west to south-west, it moved into an environment of very low wind shear, light steering flow and anomalously warm ocean temperatures, up to 2 °C warmer than normal lying just off the Northwest Shelf region. All these ingredients contribute to tropical cyclone intensification. With no inhibiting factors present, Zelia has rapidly intensified into a compact, intense tropical cyclone now heading toward Port Hedland.

Detailed attribution analysis needs to be done to work out if Tropical Cyclone Zelia would be as intense if the climate had not been warming. While the six tropical cyclones that have formed this season are close to the normal range, and this first landfall is later than normal, tropical cyclone activity has been much higher than normal by measures of energy. It is clear that ocean temperatures are anomalously warm all around the coast of Australia, especially off western Australia. Warm ocean temperatures, which are linked to climate warming, are generally linked to higher tropical cyclone intensity and longevity.

Can we stop cyclones before they start?

Climate change is worsening cyclone disaster risk. Current risk reduction responses focus on reducing vulnerability and exposure. However, these approaches are not keeping up with climate change. We need fresh approaches to tackle threats from tropical cyclones, going beyond traditional methods such as stronger infrastructure and improved preparedness. We need to combine time-tested strategies with innovative new solutions to keep people, property and the environment safe. Cyclone interventions could be a potentially transformative response to climate change, and should be a priority for future research. 

At ANU we have been investigating how we might directly intervene in tropical cyclones. Intervening in the cyclone hazard itself has the potential to prevent deaths and destruction,  and reduce the costs of disaster recovery. We have reviewed a range of possible interventions such as using pipes to inject cool water into cyclone hotspots and atmospheric aerosol injection. We have identified aerosols (small airborne particles) as a strategy with strong potential to influence tropical cyclones during their early development stage to prevent their spin-up. We are working to identify potential mitigating strategies of tropical cyclone formation using a range of aerosol treatments.

Tropical Cyclone Zelia has significant destructive power and will pose a significant risk to life and property. The cyclone is forecast to make landfall today; the strongest winds will likely be closer to the centre of the Cyclone.

Tropical Cyclone Zelina has reached category five strength, the strongest category we have in Australia, and has the potential to be very destructive. Winds that can blow roofs off houses, bring down powerlines and trees, as well as flooding and coastal erosion due to the storm surge, will all pose significant risk to people in the forecast impact areas in the Pilbara. The port infrastructure at Port Hedland will be right in the firing line for Zelia and there is likely to be significant infrastructure and supply chain disruptions.

Research at Natural Hazards Research Australia shows that flooding often poses the most significant risk to life and that often this is a result of people entering floodwater. Fatalities associated with 4WD vehicles are rising sharply – 75% of all fatalities associated with 4WD vehicles have been observed in the last 15 years, suggesting people think their vehicle is suitable to drive through floodwater. You never know what is under the surface – floodwater can easily wash away the surface of the road and in seconds your life is in danger as you’re off the road, into the current and your vehicle is sinking.

Over the coming days, once Zelia has made landfall, attention will quickly move to clean-up and recovery. Research after the 2022 flooding in Queensland and New South Wales tells us that there are big picture issues that affect how people respond and recover – community connection and communication, local capacity for action, flexibility in disaster adaptation and personal control over decision making are all key aspects that influence how people manage adversity.

Zelia has the potential to severely damage infrastructure. Rebuilding will be critical, but research shows us how this can be done to minimise future damage. Our knowledge of how to build new houses to resist some of the hazards we face has increased dramatically, and must be supported by continued investments in proactive mitigation to reduce risk. Sometimes, the risk may be too high and we need to recognise when it might be best to build back somewhere different.

Climate change is influencing our weather. We should expect fewer tropical cyclones, but a greater proportion of these are expected to be severe. Heavier rainfall intensities, combined with higher sea levels will increase the risk of flooding associated with Tropical Cyclones. We must plan for this, and use scientific knowledge, to ensure Australians remain safe and we protect our environment and the places we love.

If your power has gone out your food will remain safe in your refrigerator for 2 hours. If it has been more than 4 hours, throw the food out. Resist the temptation to open fridge or freezer doors during the power cut unless you have to remove food to eat, check the temperature of the food after 2 hours, or place chilled items in the freezer. Freezers that operate at minus 18°C or below can keep foods at safe temperatures for between 1 and 2 days. If the freezer door is kept shut, a full freezer can keep food chilled for up to 48 hours, while a half full freezer can keep food chilled for 24 hours. 

Always keep frozen bricks or gel packs in your freezer to place in a cooler or esky. Remove all meats, poultry, dairy and potentially hazardous food (for example dips, pâté, ham, prepared and cooked food) from the fridge and place in a cooler with frozen bricks or gel packs evenly distributed. Salted butter, margarine and hard cheeses such as cheddar will remain safe at room temperature, as are sweet or acidic items such as jams, sauces, soft drinks, spreads, pickles and olives.

Also, remember to throw out food that was being cooked when the power failed if cooking cannot be completed properly within 2 hours. If food is already properly cooked, eat it within 2 hours or throw it out.

I'm watching Severe Tropical Cyclone Zelia with great concern. I'm particularly worried about Port Hedland, the largest town in the firing line and also our busiest iron ore export port. Even buildings and infrastructure built to the highest cyclone rating standards will receive some structural damage from the predicted extreme winds in the core of the cyclone. It's at the top of the category 5 scale. The record-breaking sea surface temperatures offshore (>31 C) are feeding this monster, along with exceptionally favourable atmospheric conditions.

Despite the small size of the system, its slow forward motion will mean prolonged extreme winds and intense rainfall around the core as it approaches and crosses the coastline. It's too early to draw a direct link between global heating and this particular cyclone, but its rapid rate of intensification and the exceptionally warm ocean heat content suggest aspects of this extreme weather event may be attributed to anthropogenic climate change.

Great Hurricane Milton in the Gulf of Mexico last October is the most recent global example of such an intense system. Luckily it weakened considerably before hitting central western Florida.

Tropical cyclones are clearly linked to global warming due to climate change, with increasing frequency and magnitude, pointed out by scientists for a while now, for example in a 2012 report of the Intergovernmental Panel on Climate Change. 

The increasing magnitude is evident in recent cyclones - for example, last year Hurricane Helene in USA impacted 500 kilometres inland. The Bureau of Meteorology is warning that the impending Cyclone Zelia in WA can be expected to similarly affect inland areas such as Marble Bar, Nullagine, Tom Price and Paraburdoo. As anticipatory measures residents and authorities in these areas should be prepared with evacuation plans in place.

There is also the likelihood of flash flooding and storm/tidal surges; preparedness measures should also consider these risks. The multi-hazard nature with compounding and cascading effects is important to note. The risk is not only from the expected strong winds of almost 300 kilometres per hour and heavy rainfall, but also from the secondary impacts of the cyclone.

The key lesson from such events is the need for establishing a nationwide, anticipatory, hurricane preparedness program in all coastal regions with a wide inland catchment that can spring into quick action.