Much of Australia’s south will likely bask in temperatures up to 8C hotter than normal next week, which could trigger an increased risk of thunderstorms over wide areas.
A dome of heat that has put parts of the Northern Territory under heatwave warnings is set to spread east and west in the coming days, before moving south by the middle of next week, the Bureau of Meteorology said.
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Parts of the Top End around Darwin have sweltered under a heatwave for much of the last two weeks, with temperatures up to 5C above normal and hitting 41C.
The bureau’s official heatwave warning is likely to stay in place for a few more days, and the heat is expected to spread into Western Australia’s Kimberley and east over the Cape York peninsula in the early part of the week.
Angus Hines, senior meteorologist at the bureau, said on Saturday: “Some of that heat from the north-west will be spreading into central Australia. It’s going to be a gradual build as that heat moves over the course of a few days starting from today.”
By Wednesday or Thursday, Hines said forecast models showed temperatures 4C to 8C above average stretching from the centre of WA to the New South Wales coast.
“Most of the country will be seeing above average temperatures,” he said.
The early part of the week would also carry the risk of thunderstorms across large areas of the south and east.
“We will see the humidity climb and that combination of warmth and humidity could feed thunderstorm developments across eastern states,” Hines said.
“It’s a messy map with broad areas that could be hit and miss [for storms]. It’s hard to pinpoint the detail … but there’s multiple areas for thunderstorm activity from Monday to Wednesday.”
Hines said the area of likely thunderstorm development was across NSW, Victoria, southern Queensland and northern Tasmania.
The bureau’s latest long-range outlook, updated on Thursday, was pointing to a hot and wet start to the summer across many areas.
Wetter than usual conditions were forecast between October and December across most of the country and, with water storages high and soils wet, this would increase the risk of flooding in the north, east and across Tasmania, the bureau said.
In November, everywhere except the areas in and around Sydney and Brisbane were expected to have above average daytime temperatures and the whole country would likely have warmer than average nights.
Global heating, caused mostly by the burning of fossil fuels, has seen the Australian continent warm by 1.5C since 1910.
This September was Australia’s fourth hottest on record, coming after the hottest August on record.