Please note: After several successful years, the Open Minds blog will be closing. For further details, please visit our FAQ

Currently showing: Climate/natural disasters > Climate change

11 May 17 13:35

Tropical Cyclone Debbie affected Swiss Re Group 1Q 2017 result with a net loss of USD 350mn. Here are the unforgettable memories of Lydia Pomp-Bojerianova, Client Executive Austria & CEE, after surviving the 'Roarrrr!' of Debbie's Eye and what Angelika Werner, Expert Atmospheric Perils, tells us about the surprising nature of Tropical Cyclone Debbie.

"The sea was completely flat like a mirror and we were wondering why the harbour had closed yesterday and no ships were allowed to run. However, wind started getting stronger during Monday and in the evening we were advised to go either to our hotel rooms or stay in a secured cyclone proven room with some of the 200 other guests and sleep on the floor. And there we were in our hotel room… for the next 23 hours. We were hit directly by Tropical Cyclone Debbie's eye, a Cat 4 cyclone moving at walking pace over the ocean, winds up to 270km/h and a diameter of 150km. Just one window and a door separated me and my family from the storm. It was terrifying. The next day we ran out of electricity and then out of water. Food and drinking water were rationed. On Thursday we were finally evacuated under the supervision of the Australian Navy and brought to mainland at Airlie Beach, where Debbie had made landfall couple of days earlier. Again no power, no water, no gasoline. Roads were flooded and power supply lines were hanging in the air, so the police wouldn't let us drive out of town. After another night in Airlie Beach, three days of travel and another flight we managed to escape Debbie. While I am still recovering from the shock of my life I have never been more grateful to work for a company helping people rebuild their lives. And for the first time I could explain my 6 years old what I am doing for living…"

Well – that's not quite how you'd imagine a holiday on a picture-perfect tropical island. But Tropical Cyclone Debbie only showed a glimpse of its devastating nature over the Whitsundays. After Debbie made landfall, the storm system expanded massively and dumped huge amounts of rain over large parts of Central and Southern Queensland as well as over Northern New South Wales. All those regions were subject to major flooding.

While Queensland is no stranger to cyclones and floods, such strong rain impacts are normally only observed during La Niña seasons, the counterpart of the better known El Niño. During La Niña seasons the waters around Northeastern Australia are comparably warm and both more natural convection supports cyclones to form, grow in size and intensify. The seasons of 1954/55, 1973/74 and 2010/11 are particularly associated with La Niña-driven floods and cyclones in Queensland.
In the current season 2016/17, the Pacific showed neutral conditions leaning towards El Niño. Even though storms can occur close to East Australia, they usually dissipate quickly over land and hence losses tend to be more wind-driven. It seems extraordinary that Debbie had loaded so much moisture, despite the climate variability pattern was in a rather unsupportive state.

But what was driving Tropical Cyclone Debbie's nature? Discussions started if we had just seen the first real 'climate change' storm, where the ever increasing overall air and sea temperatures in and around Australia (last summer has seen once again record breaking heat waves in Eastern Australia) are producing a more moisture-loaded atmosphere that can result in a so-called super-charged storm even in the absence of La Niña. Of course there is no certainty about this effect, but just another hint towards it.

… by the way, at the moment another new record is set: Tropical Cyclone Donna is currently impacting the South Pacific Islands of Vanuatu and New Caledonia with as much as Category 5 intensity and with that is the strongest ever recorded May cyclone to be observed in the Southern Hemisphere. Officially, tropical cyclone season has already ended on the 30th of April.

Category: Climate/natural disasters: Climate change, Disaster risk, Floods/storms

Location: Australia


If you would like to leave a comment, please, log in.