Australia was battling weather extremes yesterday with South Australia hit by its first tropical storm for 15 years, just as the state's north faced a catastrophic bushfire risk.

Tropical Cyclone Christine, now downgraded to a low-pressure system, brought gale-force winds and high temperatures, but no rain, to the northern parts of SA already bracing for bushfires with fuel "ready to burn".

Bureau of Meteorology acting regional director John Nairn says sustained winds of up to 55km/h were forecast and although they were not expected to do major damage, dust storms would hit some areas.

Nairn says not since Tropical Cyclone Vance in 1999 has a tropical storm tracked so far across South Australia. Christine was expected to move from Nullarbor, on the far west coast, and across the Northern Spencer Gulf.


The bureau said temperatures today across the state's north would continue to be in the late 40s. Tarcoola yesterday recorded the highest maximum of 48.2C, with Oodnadatta on 47.7C. The conditions extended as south as Port Augusta, with 46.2C.

Country Fire Service chief officer Greg Nettleton said the combination of dry, very hot and windy conditions meant the bushfire risk in some areas could not be higher. "All the fuel is dry and the drought factor for forest areas is at its maximum level," he said.

The clean-up after Christine has started in parts of Western Australia, but the worst may be yet to come in other parts. The bureau has issued fresh flood warnings for two rivers in Pilbara and a flood watch alert for the Goldfields area.

Queensland is about to swelter in a heatwave, with the mercury tipped to reach close to 50C in some parts of the state this week.

In the western Queensland town of Birdsville, the mercury could soar as high as 48C today while in Brisbane temperatures are predicted to hit a sultry 39C on Saturday.

Temperatures are expected to be 5C to 10C above the average across the state over the next few days.

Meteorologist Gordon Banks said a large, dry, hot mass of air stagnating in the nation's interior was the cause.

Banks said a run of such high temperatures was rare for Queensland.


"We do get these bursts of several days where we're seeing high 30s to low 40s through the [state's] interior," he said.

"But what we're seeing at the moment is that we're having this run of days where we're seeing mid to high 40s through the interior and that certainly is much more unusual."

A fire set off by lightning has been burning in thick bushland for days on North Stradbroke Island.

Diamantina Shire Mayor Geoff Morton, who lives in Birdsville, said it would be business as usual in the small town despite the forecast 48C heat, which is 1.5C shy of the 1972 record.

"Once it gets over 45 [degrees] it doesn't matter whether it's 45 or 55, it's still bloody hot," Morton said.

"Everything's hot, everything's hot to touch, the ground is hot ... A few more degrees is not going to make much of a difference."