Severe to extreme heatwave conditions for southern Australia

13/01/2014

The Bureau of Meteorology is forecasting prolonged severe to extreme heatwave conditions for large parts of southern Australia throughout this week.

An extremely hot air mass over western and inland Australia is forecast to spread across the southeast today (Monday), directing very hot northerly winds over South Australia, Victoria, New South Wales and Tasmania.

Temperatures are forecast to reach the mid-40s in many inland areas. Adelaide is forecast to reach 40 today, and Melbourne is forecast to reach 41 tomorrow.

Sydney will be spared the worst of the conditions with temperatures in the high 20s in the city, and high 30s in the west. Perth will be milder during the week, but will see temperatures reach the high 30s again on the weekend.

Assistant Director for Weather Services, Alasdair Hainsworth, said the Bureau had launched a new pilot heatwave forecast service, which provides a measure of the intensity of a heatwave and complements the official temperature forecast.

"What is unusual about this event, which the pilot heatwave forecast shows, is that when high maximum temperatures and above average minimum temperatures are sustained over a number of days, there is a build-up of 'excess' heat. Extreme heatwave conditions can be seen in southern NSW, Victoria and Tasmania," Mr Hainsworth said.

"The heatwave service allows the Bureau to inform the community of the extremity of heatwave events, such as this one, for their planning and preparation.

"The new service is able to map the level of intensity of each heatwave event, indicating areas of 'severe' and 'extreme' heatwave at the upper end of the scale. The current event shows large areas of southern Australia will reach severe to extreme heatwave conditions.

"The heatwave service provides a more advanced indicator than temperature alone in anticipating the impact of heat stress.

"Severe and extreme heatwaves pose significant risks to human health and safety, in particular for the elderly, who are more vulnerable to the effects of heat stress.

"When average conditions are exceeded over a period of time by continuously high night-time and day-time temperatures, heat stress becomes a critical factor in human survival and infrastructure resilience," Mr Hainsworth said.

For further information go to Heatwave assessments.