Image reproduced with the permission of the Bureau of Meteorology

By staff reporters

15 January 2014 – [Updated 16 January 2014] More heatwaves more often, that’s the general prediction from Australia’s Bureau of Meteorology, as southern parts of Australia reach temperatures of 46 degrees Celsius and threaten to go higher, and bushfires destroy homes and threaten others.

Around Perth more than 50 homes have been lost in bushfires, about 15 bushfires have broken out in South Australia as temperatures 45C on Wednesday and were expected to go higher in coming days.

UPDATE: The Bureau of Meteorology confirmed that Adelaide had taken the dubious honour of “hottest city in the world” shortly after midday today, as temperatures headed towards 46°C, with rolling blackouts expected to hit the city and electricity demand for cooling overwhelms the system.

In Melbourne, the temperature has been forecast to reach 44°C, with similar blackouts expected. The city has experienced its longest run of 40°C days since 1908.

The extreme heatwaves continues as the Climate Council released a report warning that heatwaves like this were to become the new normal.

The report, Australian Heatwaves: Hotter, Longer, Earlier and More Often, found that Australian heatwaves were becoming more frequent, intense and longer lasting.

Key findings of the report were:

  • Hot days, hot nights and heatwaves are one of the most direct consequences of climate change
  • Heatwaves have increased across Australia
  • Climate change is making many extreme events worse in terms of their impacts on people, property, communities and the environment
  • Record hot days and heatwaves are expected to increase in the future

BOM defines heatwaves

While many of us know one when we’re melting in it, until this month there was no formal definition of what a heatwave actually is.

As part of the new Pilot Heatwave Forecast, the BOM has also released a national definition that describes heatwaves as, “three days or more of high maximum and minimum temperatures that is unusual for that location”. In other words, it’s not a heatwave if it’s 40 in the shade at Tom Price for a week, but it is if Melbourne has high overnight temperatures and several days over 40 in a row in January.

According to a study by PriceWaterhouseCoopers, severe and extreme heatwaves have taken more lives than any other natural hazard in Australia’s 200 year history. For example, 374 people lost their lives to extreme heat in the heatwave that preceded the 2009 Victorian bushfires.

Because heatwaves also have implications for electricity suppliers, infrastructure, industry, emergency services and the aged care sector, amongst others, an alert system is being proposed so mitigation action can be taken.

You can check the Heatwave Forecast here