Cyclone Debbie’s devastation on Queensland is slowly emerging, with the south-east of the state and NSW next in line for wild weather.

The recategorised ex-Cyclone Debbie is bringing monsoonal rain and major flooding across central Queensland, with Brisbane and the Gold and Sunshine coasts to be hit with the wild weather from Thursday.

Brisbane and south-east Queensland will get more than one month’s rain, before the low pressure system moves offshore on Friday.

Parts of northern NSW and along the coast south to Sydney have also been issued with a severe weather warning.

Bureau of Meteorology (BoM) forecaster Brett Harrison said Brisbane experienced some patchy showers throughout Wednesday, but would face heavy rain on Thursday as Debbie makes her way through the south-east.

“The heaviest of the falls [are] expected during the latter part of [Thursday] afternoon and evening where we could see some areas picking up over 100mm and certainly couldn’t rule out over 200mm in localised areas,” he said.

On Wednesday morning, 63,000 households in the cyclone zone were without power, and could be so for up to a week, while the Bruce Highway was closed in three places, with Airlie Beach, Proserpine and Bowen still cut off by floodwaters.

Some coastal areas received 400mm of rain in 24 hours, with the Clarke Ranges, north-west of Mackay receiving 646mm, on top of 340mm on Monday.

The BoM said rivers from Ayr in north Queensland to the NSW border will experience major flooding, but there will not be enough consistent rain to see a repeat of the 2011 Brisbane River disaster.

Two thousand claims have already been lodged, but the damage bill will take weeks to calculate, especially with more flooding expected as the now-low pressure system heads south.

The clean-up from Cyclone Yasi cost insurers about $1.4 billion but it is “much too early” to estimate how much destruction Debbie has caused, the Insurance Council of Australia says.

Queensland Premier Annastacia Palaszczuk has flown into cyclone-ravaged areas where the devastating effects of the storm are becoming clearer.

Ms Palaszczuk warned of “huge” economic impacts for farmers in the cyclone zone, and of a body blow to tourism, with significant damage to Whitsunday Islands resorts.

Since dawn, images of shattered homes, businesses and critical infrastructure have steadily emerged, and it’s now certain the state faces a long and very expensive road to recovery.

Tourists walk past shops in Airlie Beach on Wednesday morning. Photo: AAP

Locals survey the damage to boats at Airlie Beach. Photo: AAP

A boat is smashed against the rocks at Airlie Beach, Wednesday. Photo: AAP

Shell-shocked motel owner Dave McInerney, who spent most of Tuesday as Debbie hit huddled in a toilet with his caretaker and dog Spotty, says he’ll likely walk away from his Shute Harbour Motel.

See Debbie’s destruction in pictures here

“This one took the cake”: motel owner Dave McInerney. Photo: AAP

The business his father started 50 years ago is in ruins, and he believes what’s left is likely to be demolished.

“I think I’ll probably pack up and go now, that’s enough,” he told AAP on Wednesday.

“I’ve worked in the Gulf of Carpentaria and seen some pretty bad storms but this one took the cake.”

Authorities say no one is known to have died, and just two people have been hurt. But they’ve warned that with more wild weather and likely flooding ahead, that could change if people try to cross flooded roads.

Prime Minister Malcolm Turnbull said everything possible was being done to help cyclone victims, including getting the army on the ground, as well as choppers, planes and ships to assess the damage and bring supplies.

NSW, Sydney to cop it next

Meanwhile, the BoM issued a severe weather warning on Thursday and Friday with damaging winds and heavy rainfall for north-eastern NSW.

The rain may lead to flash flooding in an area which has only just recovered from days of pounding rain and flooding earlier this month.

The BoM forecast the Northern Rivers district to receive 100mm over 24 hours, with some areas to exceed more than 200mm.

Damaging winds averaging 65km/h with gusts of more than 90km/h are possible along the coast as far south as Sydney, the BoM noted.

– with AAP