Tropical cyclone Jasper grows into Category 5 monster - check our tracker and map to see when and where Australia will be hit

Tropical cyclone Jasper has been upgraded to a category 3 system and is expected to strengthen further as it moves towards the Queensland coast.

Jasper is forecast to reach high end category 4 intensity later on Thursday and possibly category 5 on Thursday night, the Bureau of Meteorology said in its latest forecast.

The 'unusual' cyclone tracked south-southwest into the Coral Sea overnight with wind gusts expected to reach 195km/h on Thursday night.

'At this stage the highest risk of a cyclone impact is the region north of Mackay but severity of the coastal impact remains highly uncertain at this stage,' the bureau said.

Over the weekend Jasper is likely to weaken but will remain as a tropical cyclone next week.

Jasper is not only the first tropical cyclone of the season but is also believed to be the first to form off Australia in December during an El Nino.

'It is rare to see a December cyclone let alone one where we do have El Nino,' a bureau spokesperson said.

'It is unusual to be seeing this. There aren't too many cyclones we have seen through the month of December let alone early December.'

The bureau will issue regular updates to keep communities informed as the situation evolves over coming days.

It said the slow-tracking cyclone might provide plenty of time for communities to batten down the hatches before a potential impact.

Australia's cyclone season is usually from November to April, typically peaking in Queensland in February and March.

'There is a potential for tropical cyclone Jasper to move near the Queensland coast next week (but) there is large uncertainty as to which parts of the Queensland coast will be impacted,' senior meteorologist Dean Narramore said on Tuesday.

'The bureau will issue regular updates to keep communities informed as the situation evolves over the coming days.'

Meteorologist Steven Hadley said some modelling suggested Jasper could travel south and cross the coast near Brisbane as a tropical low.

'But more likely than not, it would be in the tropical areas of Queensland ... it's just really too early to say just yet,' he told ABC radio.

The bureau's technical bulletin said recent guidance favoured a scenario where Jasper approached the Queensland coast between Cooktown and Mackay next week.

'A small amount of guidance has a more southerly track, consequently moving the system towards the Queensland coast, south of Mackay,' it said.

In other states, record-breaking temperatures loom as a scorching heatwave looks set to propel the mercury above 40C. 

A band of high intensity pressure over central and northern Australia this week will see extreme temperatures in many outback regions, stretching as far down as Queensland's southeast.

Maximum temperatures are expected in about a third of the country, with weather tipped to reach a blistering 44C or higher by Thursday in some parts. 

Parts of Western Australia and South Australia at their shared border will get up to about 45C on Wednesday.