By Keira Jenkins, Glenn Moore and Rex Martinich in Brisbane

THE number of people killed in south-east Queensland storms has risen to six, with another boating accident victim found.

Ambulance officials initially said two people had been found dead after a large motorboat capsized at Moreton Bay on Tuesday afternoon with 11 people aboard.

Paramedics took eight patients to hospital in a stable condition, while one male remained unaccounted for.

Police then confirmed later on Wednesday the body of the remaining missing person had also been found.

The three deceased are known to be a 48-year-old from Alexandra Hills, a 69-year-old from Meridan Plains and a 59-year-old from Tingalpa.

Search and rescue efforts have been finalised and police will prepare a report for the coroner.

Police Commissioner Katarina Carroll said the deaths and several others had occurred during a period of “extraordinarily difficult weather” and urged people in affected regions to listen to authorities and stay out of dangerous areas.

“It has been a very tragic 24 hours due to the weather,” she said.

The body of a nine-year-old girl was found following an extensive police search on Tuesday evening after she was lost in stormwater drains in Brisbane, while that of a 40-year-old woman was recovered from the Mary River in Gympie.

The woman was one of three swept into the water by the Kidd Bridge. One 46-year-old managed to get to safety, while another is still missing.

Christmas storms had already accounted for one death on Monday after a 59-year-old woman was fatally struck by a falling tree on the Gold Coast.

Queensland Premier Steven Miles said on social media he was heartbroken to hear of the deaths.

“Every Queenslander will have those families in our thoughts and prayers,” he said.

Gold Coast mayor Tom Tate said his city was “not out of the woods” but forecasts for clearer weather would allow the SES to attend 800 storm-damaged homes.

Cr Tate urged residents to check on vulnerable neighbours and not to attend hospital unless it was an emergency due to a 30 per cent spike in admissions linked to power outages.

“We are assessing all the New Year’s Eve event venues right now because it is going to be very warm and if there’s fire danger (from fireworks) we might have to cancel some,” he said.

Queensland Energy Minster Mick de Brenni said Energex power grid crews had been brought back early from flooding in Cairns to help restore services around the Gold Coast.

“Some of the crews have described the damage to the power system as unprecedented,” he said.

Mr de Brenni said 85,700 homes and businesses in the Gold Coast and Logan areas and about 3000 around Brisbane had lost power on Tuesday night but 45,000 of those had now had services restored.

“There are about 950 instances of power lines down. That is an extraordinarily high number,” he said.

Severe weather lashed parts of Queensland’s south east on Christmas and Boxing Day.

At Gympie a wind gust of 100km/h was recorded while hail the size of golf balls was spotted at Zillmere in Brisbane’s north.

South-western Jindalee copped 62mm of rain in an hour.

The Bureau of Meteorology said further severe thunderstorms were possible on Wednesday around central and northern parts of the Queensland coast, and potentially reaching south to Brisbane.

Heatwave conditions in the state’s north prompted warnings, with maximum temperatures across the Gulf region expected to reach the low 40s.