Campbell Newman said he first contacted Defence Minister David Johnston just after 6pm on Thursday night "and indicated that I thought we had a big problem here".

After speaking to the Brisbane Lord Mayor Graham Quirk, who had been in contact with the State Emergency Service, Mr Newman made his formal request at 7.30pm.

Personnel from the Enoggera barracks were deployed across Brisbane at 10pm to provide assistance to SES and emergency service workers, clearing debris so the repairs could begin.

"It is a very significant storm," Mr Newman said on Thursday night, having inspected damage at Kangaroo Point.

"The Insurance Council have declared a catastrophic weather event and are mobilising their collective disaster arrangements.

"The belief at this stage is it is bigger than The Gap storm [which hit Brisbane in 2008 and caused tens of millions of dollars in damage], I think that is safe to say.

"Sadly, I am calling this the biggest storm that has hit Brisbane since 1985."

At 9.30pm, 88,000 homes across the region were without power, with more than 400 power lines down.

Many will take at least 24 hours to repair.

Water supply issues had been identified in Bracken Ridge, Kelvin Grove and Seventeen Mile Rocks, with authorities mobilising to get bottled water out to the affected suburbs.

Mr Newman said the latest information he received suggested Brisbane's south had been hit particularly hard, naming Annerley as one of the suburbs to have suffered the most damage.

He said he had left Parliament and was sitting in his car on William Street as the first hail stones hit and knew the storm would be bad.

"I was quite scared," he said.

"I thought this is big, this is huge.  This is a really big event.  I was worried for the people of this city, worried for my own wife, who I knew was walking along Kedron Brook.

"...I hope we don't find there's been a tragedy tomorrow morning."

Mr Newman said he was aware of at least one woman who had been injured by debris and he was "hoping and praying we don't have someone who has died this evening or serious injuries".

"If that's all it is, I'll be absolutely amazed because of the ferocity of the thing," he said.

Mr Newman urged people to stay inside and away from the damaged areas, allow the authorities to clear the debris and begin repairs without the threat of additional injuries.

Mr Newman also asked people to check on their neighbours, particularly the vulnerable or those with medical conditions.