The worst of the storm activity looks to be over for the Brisbane region after the city's inner-west copped a battering, with hail bigger than golf-balls pelting Kenmore and surrounds.
Bureau of Meteorology senior forecaster Jonty Hall said on Sunday night the biggest hail stones reported were 9 centimetres in diameter around Boonah, though Mt Coot-tha, Bardon and Toowong were pelted with stones as large as tennis-balls.
Energex was working to restore power to nearly 10,000 homes in the Brisbane City Council region yesterday evening, with homes in the Lockyer, Sunshine and Ipswich council areas also affected.
The State Emergency Service reported receiving a call every 30 seconds in the first ten minutes immediately following Sunday night's storm.
The city's road network was also affected by the wild weather, with vehicles stationary at the Gateway Motorway, Deagon, and hazardous conditions reported for the Western Freeway.
Translink services were interrupted across the city due to debris and fallen objects, with major delays to the Ipswich and Cleveland lines.
BoM chief forecaster Dr Richard Wardle, meantime, defended the BoM amid claims that it failed to adequately warn southeast Queensland residents that Saturday's destructive morning storm was about to hit.
The massive storm - flagged in a brisbanetimes.com.au story Friday - was clearly visible on a BoM radar image taken at 10.12am Saturday. The radar showed the intense storm centred between Amberley and the Ipswich CBD, moving east towards Brisbane.
However the bureau did not issue an alert about the severe weather until 10.50 am, after the storm front mashed into Brisbane city and about the same time the Queensland Police posted this message on its Facebook page, accompanied by a photo of the deluge in Roma Street:
"Outside Police HQ...might need to get that poncho out if you're walking. #qldstorm"
(The police also put out a general warning at 9am Saturday for severe storms, with a spokesperson telling brisbanetimes.com.au today that they rely on the BoM for specifics.)
The bureau's warning said that severe thunderstorms had been detected on the radar near the Brisbane CBD, Logan City and Strathpine, and that they were moving towards the east, with damaging winds expected.
The BoM began issuing regular warnings after that, which combined with safety messages from the Queensland Police, Energex and Emergency Management Queensland, began to give a fuller picture of the storm's severity.
Responding to criticism on Facebook and Twitter that Brisbane residents were insufficiently warned about Saturday’s brutal weather activity, Dr Wardle said the BoM had been predicting the likelihood of severe thunderstorms up to 48 hours before the pattern hit.
But the rapidity with which the storm developed left little time to issue a warning he said.
“Yesterday’s [Saturday's] storm developed very rapidly,” Dr Wardle said. “Usually they develop before they reach Brisbane so we have plenty of time to warm the populated areas.
“This one developed over Brisbane very rapidly over a few minutes – it didn’t pass the threshold for severe until it was basically upon us.
“We’ve got to be careful about issuing these severe thunderstorm warnings... We could actually have a lot of false alarms which would render the service ineffective.”
Dr Wardle said the threshold weather patterns needed to pass before warranting a severe weather warning was decided by factors such as wind, hail and rainfall.
Typically wind gusts in excess of 90 kms an hour, hail with a diameter of at least 2 cms and heavy rainfall conducive to flash flooding were the key criteria he said.
Mr Hall said Saturday's storm activity over the Darling Downs brought reports of hail stones as big as 10 cms across.
And while there was flash flooding in Brisbane, Mr Wardle said the rainfall levels captured across some of the affected areas was relatively low at only 30 mm.
The dramatic footage of flooded streets and suburban destruction was partly due to creeks which were already full, and poorly prepared drains and stormwater systems.
"Storm season is upon us," he said. "It’s important to be prepared."
Ipswich City Councillor Paul Tully, meantime, has called for a public apology from the bureau for its "monumental failure" to issue a timely storm warning.
"They must have been enjoying a long morning tea or an early lunch not to realise the intensity of the approaching storm," he said.
Cr Tully pointed out that his own alert to his 1600 followers on Facebook, issued at 10.21 am and saying, "It’s coming. Moving now towards Ipswich’s eastern suburbs after observing a line of storms on a 50km front from Wivenhoe Dam south to Harrisville," came a full 30 minutes before the Bureau’s first official warning.
Other critics took to Facebook.
"Methinks the Australian Bureau of Meteorology (Queensland Weather Warning Feed) must have had their Chrissy drinks last night. They are blaming the speed of this morning's storm for their not being able to issue a warning until 5 minutes after it hit (rattling their building in the process)" wrote Lipscome Mick, linking to the feed.
"You are hopeless !!! More chance of making your own decisions by looking at the sky !!! Your warnings are late and worthless ..." wrote Dallas Garton.
"freaking hopeless.. who has been sleeping on the job then ??" wrote M'lady Stompalot.
Michelle Truesdale reflected on the lack or outreach to social media users — despite most other emergency organisations regularly updating followers of their Facebook pages and Twitter feeds:
"Your last post was 28 October. No warnings of super storm cells expected in SE Qld & Nthn NSW today & tomorrow. (And one huge storm has already hit Brisbane this morning.). Think I might 'unlike' this page."
During storms, Emergency Management Queensland advises that people should:
- Move your car under cover or away from trees.
- Secure loose outdoor items.
- Avoid driving, walking or riding through flood waters.
- Seek shelter, preferably indoors and never under trees.
- Avoid using the telephone during a thunderstorm.
- Beware of fallen trees and powerlines.
- For emergency assistance contact the SES on 132 500.