Southeast Queensland should prepare for a brawl on Thursday in which several supercell storms come from the west and bring “huge hail,” the Bureau of Meteorology (BOM) has warned.
- According to BOM, super cells will bring destructive winds and huge hail to southeast Queensland
- The weather system is expected to be most intense on Thursday
- Despite heavy rainfall, the water supply to Wivenhoe Dam increased only slightly
After the region just weathered a soaking on Monday, the region is now facing a new destructive weather system that is moving slowly and will likely have severe thunderstorms with a possible “hail” that the office classifies as anything larger than 5 centimeters.
But the potential for tornadoes like the one that cut a swath around Bathurst, New South Wales last week, is slim, said meteorologist Dean Narramore.
He said cold air coming over Australia would meet the warm, humid air from the Coral Sea and lead to an outbreak of severe thunderstorms typical of this time of year.
“It’s kind of a combination of more moisture across the country that provides more energy for the weather systems that are moving.”
Tornado activity unlikely
While the storms that produce huge hail and destructive winds are classified as supercells, they are unlikely to unleash tornadoes in built-up areas of southeast Queensland as they arrive en masse.
The tornado that hit the Bathurst area last week sparked speculation that a similar weather system could form across Queensland, but Mr Narramore said it was not likely.
Mr Narramore said that the scenario where storms occur in a group, with multiple storms in close proximity to each other, reduces the likelihood that they will create a tornado.
He said a tornado was more likely if, given the right atmospheric conditions, it was just a supercell storm, rather than a group of four or five all competing for the same energy from the atmosphere.
“As they [the storms] As you get closer to the coast, they tend to freeze all together, and when there are storms and the like, the chances of getting tornadoes are less, ”said Narramore.
“It has to be discrete, isolated storms with all the right ingredients for a tornado to form. When there are five or six storms, they are all fighting for that energy.
“There is a possibility that the [tornados] further inland and west of the Ranges like Darling Downs, but even more to the north of NSW, but even then the chance is very slim. “
Super cells are supposed to hit the southeast
Mr Narramore said the office was unable to pinpoint where the storms were likely to be strongest by Thursday morning, but predicted they would generally come from the west or northwest.
“It’s not until the morning of the day that we can see how the atmosphere is built, where the converging wind limits and mountain ranges serve as a focal point to provide a lifting mechanism to initiate the thunderstorms,” he said.
“They will likely come from Kingaroy through Toowoomba and Esk towards Southeast Queensland as they move away from the mountains.
Heavy rain registered
Heavy rains have been recorded in the past two days, with Mount Glorious reaching 75mm, Beerburrum on the Sunshine Coast 48mm and Brisbane 35mm.
Gatton and Amberley also had large rains with 36 and 36 respectively. 38 mm – the highest rainfall in these areas in four years.
Despite the large sums of money, the downpour did little to shift the level of negative pressure water supply in the southeast.
The water supply to the Wivenhoe Dam rose slightly from 40.2 percent on October 6 to 40.7 on October 9, but then fell back to 40.2 percent on October 12.
Seqwater has warned that water restrictions would likely come into effect in southeast Queensland if the total number of dams in the area fell below 50 percent, which could be the case by December.