Monster supercell storms, intense rainfall and flooding could hit anywhere, anytime in the coming months, ‘really rolling the dice’ for more unpredictable, extreme weather for Australia’s east coast, the Bureau of Meteorology (BOM) has warned.
- A combination of ‘climate drivers’ means that severe weather could hit at any time this spring and summer, says BOM
- It said the ground was already so wet that it would not take much for the floods to rise
- Sandbags are available for Brisbane residents to collect from depots in Zillmere, Newmarket, Morningside and Darra
It comes after unexpectedly powerful storms wreaked havoc on Queensland’s Gold Coast and its hinterland on Friday morning, dumping more than 300 millimeters of rain.
The supercell system, triggered by a low pressure system off the coast, hit in the dark of night and triggered landslides, floods, rescues and evacuations.
BOM senior meteorologist Kimba Wong said predicting the type of weather system was a “notoriously” difficult task.
“We had … reports … that the chance of heavy rainfall would be possible in the Gold Coast region during this period,” Ms Wong said.
“It looked like the biggest risk would be northern New South Wales, but overnight we saw the low develop a bit further north and concentrate the higher falls over the Gold Coast region.
“These systems are notoriously difficult to predict, and the models don’t do a very good job of pinpointing their exact position, which is really critical for rainfall forecasting.
“We had severe thunderstorms in the forecast from yesterday, but we saw these warnings start to be issued during the late evening hours … around midnight.
“The information was out there — sometimes it’s not the most available information, I guess.
“Of course, familiarizing yourself with our service and where to find the best information on our website and our app is also the best way to serve yourself.”
Wong said a combination of “climatic factors” meant severe weather could hit any time this spring and summer.
“That is clear [third] The La Niña statement recently, we also have an active negative dipole in the Indian Ocean, which means there is warmer water off the northwest coast of Australia – that water is basically evaporating into the air and available for rain,” Ms Wong said.
“We also have a positive southern annular mode … and this positive phase also tends to lead to the wetter outlook during the spring months for much of Queensland.
“These climate drivers are really rolling the dice for wetter than average conditions over the coming months.”
Ms Wong said with the ground already so moist, it would not take much for the water to rise.
“We’re already starting the wet season from a really wet landscape – we’re seeing a lot of the catchments respond very quickly to rainfall,” she said.
“The landscape is currently much wetter than at the same time last year and the year before.”
The intensity of Friday morning’s storms surprised campers at the Big4 Gold Coast holiday park in Helensvale.
Natalie Johnson and her family were at the campsite on holiday from Victoria when they were woken to intense rain at around 10am.
Mrs Johnson said it came as a shock, with the water rising within minutes.
“We went to bed and about 12 o’clock we woke up just because the rain was so heavy and it hadn’t let up,” Johnson said.
“We had no idea it was coming – it was about 13 minutes from when we saw the water rising to the point where we decided we had to go.
“It was hell because our kids were in the swag in the back so they woke up to us screaming at them to get up and get out.
“There was another guy [at the site] from Ballarat and my husband said to him, ‘let’s go back to Victoria where it normally rains’ because we’re just not used to it here.”
Andre Chettle is also counting his losses after battling waist-deep water at the campsite.
“We started panicking … around 1 in the morning — we didn’t have time to pack all our stuff — we got out of our swags and jumped in the car and took off,” he said.
“Come back and the water was waist high – it’s just devastating, to lose … mostly everything – it’s just pretty sad.”
‘Really good time’ to prepare
Ms Wong said Queensland residents and interstate travelers should stay across warnings on the BOM’s website, with more rounds of flooding rain likely.
“It’s a really good time to consider how prepared you are, what you can do to prepare yourself and your property for the coming wet months,” Wong said.
“If you’re planning outdoor activities … during these wetter months, make sure you keep up to date with the latest forecast, keep an eye on the radar and our warnings page for the latest information just to make sure you’re prepared as you can be.
“Obviously, we’ve had some pretty severe flooding in much of the state over the last year or so, so definitely just a situation to keep knowing these climate factors are at play.
“It’s a pretty stressful situation to be caught in.”
Brisbane Lord Mayor Adrian Schrinner said sandbags were available for Brisbane residents to collect from depots in Zillmere, Newmarket, Morningside and Darra over the next two weeks.
“Two more Super Sandbag Weekends are planned this weekend and next, with thousands of Brisbane residents already taking the opportunity to prepare their homes early ahead of a potentially severe La Nina season,” Mr Schrinner said in a Twitter post.