Heatwaves represent a significant natural hazard in Australia, arguably more hazardous to life than bushfires, tropical cyclones and floods.  In the 2008/2009 summer, for example, many more lives were lost to heatwaves than to that summer’s bushfires which were among the worst in the history of the Australian nation. Yet for many years, these other forms of natural disaster have received much greater public attention than heatwaves. This might be changing in Australia however, as health authorities increasingly use weather forecast information to become proactive in providing advice to the community on how to mitigate the effects of heatwaves. Significant community engagement took place during the 2013/2014 Australian summer, a summer which generated some significant heatwaves, comparable to those of 2009, 2004, 1939 and 1908. 

In January 2014, the Australian Bureau of Meteorology introduced a pilot national heatwave forecasting service, to issue forecasts of forthcoming non-severe, severe and extreme heatwaves. The service is based on the excess heat factor (EHF) or heatwave intensity concept, which quantifies the extent of the temperature elevation during a heatwave in a manner relevant to the expected impact of the heatwave on human health. The forecasting system makes use of both daily maximum temperatures and daily minimum temperatures, the latter providing implicit information about average humidity levels, without humidity being included explicitly in the calculation.

This presentation will document the heatwaves of the 2013/2014 Australian summer, in terms of the EHF metric, and will describe how well they were forecast by the new service.