Key Takeaways
- A broad heatwave is spreading across Australia, with temperatures more than 10 degrees Celsius above average in some areas.
- The heatwave is expected to linger in the northern outback well into next week, with daily temperatures above 40C.
- The Bureau of Meteorology’s latest modelling suggests that this summer could be one of Australia’s hottest on record.
- A severe heatwave warning is in place for parts of New South Wales, including Sydney, with temperatures expected to reach up to 41C.
- Relief from the heatwave is expected to arrive in southern Australia with a southerly buster, but northern Australia can expect the heat to persist.
Introduction to the Heatwave
Just days into summer, a broad heatwave is already spreading across Australia, bringing with it temperatures more than 10 degrees Celsius above average in some areas. The heatwave is expected to linger in the northern outback well into next week, with daily temperatures above 40C. The Bureau of Meteorology’s latest modelling suggests that this summer could be one of Australia’s hottest on record, with maximum temperatures expected to be 1-2C above the long-term average across most of the country.
The Spread of the Heatwave
The heatwave began on the west coast, with Perth experiencing its hottest start to summer on record with a high of 39C on Monday. By Thursday, the heat had spread to south-east states, with Adelaide and Melbourne reaching 35C, their warmest days since March. The heatwave is expected to continue to spread, with temperatures in eastern New South Wales expected to reach up to 40C. The highest temperatures relative to average will impact eastern New South Wales, including highs near 40C in Western Sydney.
Fire Dangers and Heatwave Warnings
The highest fire dangers on Friday will be in the Riverina and Mallee, where temperatures from 38C to 41C will combine with winds to 45 kilometres an hour and humidity down around 10 per cent. A severe heatwave warning is in place for parts of New South Wales, including Sydney, with temperatures expected to reach up to 41C. The Bureau of Meteorology uses the excess heat factor (EHF) to monitor and forecast heatwaves, which takes into account the temperature, humidity, and wind speed to determine the level of heat stress.
The Excess Heat Factor
The EHF is a measure of how much of a shock to the body the forecast temperatures will be, compared to the weather over the past month. This method ensures that hot cities like Darwin are not warned of a heatwave every day, and cooler cities like Hobart are warned during spells of relatively high temperatures, even though they may seem cool by mainland standards. The calculation for a heatwave is also based on the minimum temperature and the maximum, since cooler nights allow some recovery from each day’s heat.
Relief from the Heatwave
Relief from the heatwave is expected to arrive in southern Australia with a southerly buster, which should reach the far South Coast during Saturday evening and track to Sydney in the early hours of Sunday. However, northern Australia can expect the heat to persist, with highs above 40C expected to continue well into next week. The Bureau of Meteorology’s seasonal outlook suggests that this summer could be one of the warmest on record, with maximum temperatures expected to be 1-2C above the long-term average across most of the country.
Looking Ahead to Summer
The latest modelling released by the Bureau of Meteorology suggests that this summer could be one of the warmest on record, with maximum temperatures expected to be 1-2C above the long-term average across most of the country. At these levels, the season’s mean temperature would land in the top five warmest on record, comparing all summers since 1910. The Bureau’s seasonal outlook also suggests that the pattern of hot winds from the north could frequently repeat this summer, leading to a prolonged period of hot weather.