Australia's summer has been called everything from “extreme” to “angry” and for large swathes of the country those adjectives still apply.
Cities such as Melbourne and Adelaide are midway through long heatwaves with no relief expected until Thursday. Nationally, summer was the hottest since consistent records began in 1910.
The big dry now extends across much of southern Australia and even the Top End is looking at its driest “wet” season in two decades.
Along the east coast, communities from the Illawarra in NSW to Bundaberg in Queensland continue to clean up after several bouts of heavy rain and even tornadoes.
In other words, the Climate Commission, which this week released “The Angry Summer” report, will probably need to update its tally of 123 heat and rainfall records because summer hasn't thrown in the towel.
Tropical cyclone Sandra, meanwhile, is a category three storm arcing away from the Queensland coast. It's expected to turn south by the middle of next week and may bring more rain if it closes in on the saturated east.
“How close it gets to the Australian coast is anyone's guess at this point,” said Karl Braganza, head of climate monitoring at the weather bureau.
What Sandra won't do is bring much moisture over the country's parched south. “Certainly, there's no significant rainfall in the forecast period over most of Australia,” Dr Braganza said.
A slow-moving high-pressure system means conditions are expected to be stable over much of south-eastern Australia. That suggests little deviation for Sydneysiders between minimums of 19 and maximums of 28 for the next week, with a few showers added to the mix.
For Melbourne conditions are similarly stable – but far less comfortable. Friday, earlier seen as the one day that may break the sequence of 30 degree or higher days, reached that mark early this afternoon as clouds cleared.
The next five days are expected to exceed 32 degrees – rising to 37 by Wednesday – with overnight temperatures likely to touch only 21 degrees on the coolest nights. Sultry conditions are adding to the discomfort.
If the mercury reaches 30-plus degrees as expected, the 10-day stretch will smash the previous longest run of such heat by two days. The last time, the city had eight consecutive days like this was February 1961.
The weather bureau, in fact, had more than an inkling that this summer would be hot. In early December, it issued a special climate statement noting how much of eastern Australia had record heat in November.
“We were seeing columns of warm air moving across Australia,” Dr Braganza said. “Internally, we were thinking 'we could be in for a very warm summer'.”
Ambulance Victoria, meanwhile, has warned Melbourne festival goers to take care to avoid heat stress over the long weekend, including Monday’s Moomba parade. The bureau is forecasting 34, 32 and 34 degrees over the next three days for the city.
‘‘We’re expecting a lot of people out in the environment, in the community, and that always leads to lots of work,’’ emergency manager Justin Dunlop told reporters.
‘‘What we’d like people to do is when they’re partying by all means drink responsibly but don’t forget to drink lots of water.’’
A new scientific report into heatwaves in Australia has found that the number of heatwaves is on the rise.
‘‘We are certainly seeing more heatwaves coming up in the last 60 or so years,’’ said Sarah Perkins, a research fellow at the Australian Research Council’s Centre of Excellence for Climate System Science, based at the UNSW.
‘‘This is particularly apparent for north-east Australia and parts of south-east Australia,’’ she said.
The paper, On the Measurement of Heatwaves, examined the 1951-2008 period, and is co-written by Lisa Alexander, also at the UNSW. It has been peer-reviewed and approved for publication in the American Meteorological Society’s Journal of Climate.
The report also seeks to standardise the definition of heatwaves, and settled on three consecutive days when the temperature is among the 10 per cent warmest for that day - as gauged by maximum, minimum and average heat.
Generally Melbourne gets three or four heatwaves a season, where the longest event lasts about four to five days. ‘‘Based on the maximum temperature index, the peak of the heatwave is about 12-13 degrees above the summer-time average,’’ Dr Perkins said.
There is ‘‘not too much difference’’ in the heatwave trends for Sydney and Melbourne, she said.
The bureau's Dr Braganza said while there is a steady upward trend in average temperatures since the mid-20th century in Australia, the trend in extremes is more apparent in the last few decades.
"This is consistent with the distribution of weather shifting to higher temperatures - eventually a change in the mean will lead to significant increases in extremes," he said.
In the meantime, one thing that no longer seems to apply is an imported European convention, that summer begins on December 1 and finishes when February ends.
- With AAP
- Sydney Morning Herald