Twin cyclones, Marcia and Lam hit Australia

Tropical Cyclone Marcia has caused significant damage in Rockhampton, Queensland, after tearing through land west of Yeppoon, a nearby coastal town.

The very worst of the cyclone missed the small central Queensland coastal town but it still brought destructive winds of up to 141km/h.

Former Rockhampton resident Carmel Barnfield on the Gold Coast said her Yeppoon sister Anne Maree's family was huddled together inside their bathroom at Yeppoon worried about losing the roof on their home.

"They think they are losing their roof and they are not moving," Carmel said on Friday.

"She is in Yeppoon, about 10 kilometres west of the main part of town, in Barmaryee."

"It's a big home, it's a farm.

"There has been roof damage already and they have lost everything, all their sheds; their boat shed, their granny flat."

At 2pm (5pm NZ time), the cyclone's most destructive core was about five kilometres south-southwest of Rockhampton, surging south at about 20km/h an hour.

Marcia was downgraded to category three at 1pm (local time) but was still producing wind gusts of up to 205km/h.

Residents along the Capricornia Coast in central Queensland have been warned to remain inside, particularly those in Yeppoon and Rockhampton.

Queensland Premier Annastacia Palaszczuk urged people to stay alert.

"My message to all the people in Yeppoon and those coastal areas is please still stay indoors," she said shortly after noon.

"Still stay indoors, do not leave your home, do not go outside, please stay where you are.

"We have heard of some reports of flooding, starting to occur now in Rockhampton.

"So my message to all of Rockhampton residents is please stay indoors.

"The eye of this storm is headed directly towards you."

A cyclone warning is current for Shoalwater Bay to Double Island Point, extending inland to Moura, Biloela, Monto, and Mundubbera.

Shayne Harris and her two children were hunkered down in Yeppoon's St Brendan's College chapel as the cyclone passed.

They left their home in Byfield, close to where Tropical Cyclone Marcia made landfall, on Thursday because they were worried about danger from trees nearby.

She is hoping for the best when she returns but is worried there will be nothing left.

"From a neighbour there they said there's no leaves on the trees and trees are falling over," she said.

"We're just hoping that things aren't too bad.

"The problem is that even when this is all over we won't be able to get home until all the creeks go down because it floods out there."

Airlines have cancelled a string of flights to affected areas, including those to Bundaberg, Gladstone, Hervey Bay and Rockhampton.

Brisbane was bearing up "reasonably well" with the rain it has received to date, Lord Mayor Graham Quirk told reporters on Friday morning.

The Bureau of Meteorology warned rain falling throughout Friday in south-east Queensland was from a separate trough and was likely to intensify as the cyclone tracked further south.

Dozens of roads on the Sunshine Coast, Brisbane and the Gold Coast have been flooded.

A severe weather warning is current for damaging winds, heavy rainfall, abnormally high tides, dangerous surf in areas south from the cyclone to the New South Wales border.

A Queensland Fire and Emergency Service spokesman said there were more than 740 fire and rescue personnel, 11,500 RFSQ volunteers, 380 auxiliary firefighters and 1,300 SES volunteers ready to respond to the cyclone.

State Emergency Service volunteers had received more than 2000 requests for assistance in the past 24 hours, mostly in Brisbane and the north coast areas.

STORM'S INTENSITY A SHOCK 

Cyclone Marcia's rapid jump from a category one tiddler to a category five monster has surprised Australian Bureau of Meteorology experts, a senior forecaster says.

And it comes as a category four storm, Cyclone Lam, hits the Northern Territory - the first time meteorologists have seen two storms of such magnitude hit Australia simultaneously.

On Thursday morning, Marcia was a weak category one system which was forecast to reach category two before it hit the Capricornia coast in Queensland.

READ MORE: What is a category five cyclone?

But by 5pm (local time), Marcia had intensified rapidly to category four - the same intensity as Cyclone Tracy, which flattened Darwin in 1974.

Marcia strengthened to category five before it crossed the coast this morning, about 8am local time (10am NZ time). 

In the Australian Bureau of Meteorology's latest advisory at 11am local time (1pm NZ time), Marcia was downgraded to a category four cyclone.

Cyclone Lam crossed the coast between Milingimbi and Elcho Island around 2am (local time) with gusts up to 250kmh.

The cyclone hit Galiwinku, Milingimbi and Ramingining, about 560km east of Darwin, and authorities are having difficulty communicating with the affected areas.

While twin cyclones reaching Australia are uncommon, Friday's combination may be the first involving storms of category 3 or higher, said Phil Perkins, a meteorologist with the Bureau of Meteorology in Darwin.

"It's the first time that we have seen two severe cyclones occurring at the same time," Perkins said.

'THIS WILL BE A CALAMITY'

Queensland Premier Annastacia Palaszczuk has been briefed by emergency chiefs.

People have been self-evacuating from towns in the firing line, including at Yeppoon, where an emergency alert went out by text telling people in low-lying areas to move.

The premier said the full brunt of the cyclone will be felt in the Yeppoon area, and there was great concern for human safety.

Palaszczuk said the cyclone was expected to later hit Rockhampton as a category three system.

She said a very dangerous storm surge would occur in many communities along the coast - 2.6 metres above what is normal at a high tide.

Police Commissioner Ian Stewart said a disaster is looming for parts of Queensland, adding it would be a calamity.

"I have to say, ladies and gentlemen, that within the next couple of hours, even our emergency services personnel will be withdrawing and they will be going to places of safety so that they are ready as soon as the eye has passed, as soon as the danger has passed, that they can get out and assist members of the public," he said.

"This will be a calamity, there is no doubt about that."

EXCEPTIONAL INTENSIFICATION

It's not one of the three most powerful cyclones to hit the Queensland coast in the past century, although it is equal in intensity to Cyclone Yasi, which devastated north Queensland in 2011.

Compared to Yasi, Marcia's physical size is much smaller, Bureau of Meteorology national weather centre senior forecaster Jenny Sturrock said.

Yasi was one of the largest cyclones ever to hit the coast in terms of physical size, but smaller storms like Marcia can change rapidly.

"It's very difficult to predict how a smaller cyclone can intensify," Sturrock said.

"The smaller ones can undertake a very rapid intensification, and that can make them very difficult to predict.

"That's why we have always been stressing to the local community to keep abreast with the latest information at all times.

"Sometimes with those smaller systems, the atmospheric conditions can be more on a local scale rather than a broader scale to favour development."

Marcia's rapid intensification was exceptional.

The intensification was a surprise for BOM forecasters.

"It's quite a remarkable upgrade," Sturrock said.

"I was on yesterday and we saw the upgrades coming through late yesterday afternoon. Obviously the priority is then to make sure all the warnings are updated as soon as possible."

Palaszczuk said she'd speak to Prime Minister Tony Abbott this afternoon to discuss what help can be provided for what will be a terrifying and destructive event in the state's history.