Weekend thunderstorms forecast for northern Australia with south to see temperatures drop

<span>The Bureau of Meteorology says warm and humid conditions in the tropics will push wet weather over Australia this weekend.</span><span>Photograph: Dave Hunt/AAP</span>
The Bureau of Meteorology says warm and humid conditions in the tropics will push wet weather over Australia this weekend.Photograph: Dave Hunt/AAP

Thunderstorms are expected to continue this weekend on both sides of the country. Warm and humid conditions in the tropics will push wet weather over Australia, with the possibility of severe storms in parts of Queensland.

Rain and thunderstorms have developed over parts of eastern Australia almost every day this month, with severe thunderstorms hitting parts of Queensland and New South Wales on numerous occasions in the past fortnight.

Northern Queensland, the Top End of the Northern Territory and parts of Western Australia have all been dealing with ongoing heatwaves, which are forecast to continue with patchy respite only for areas which will get rainfall.

Angus Hines, a Bureau of Meteorology senior meteorologist, said people in the southern states can expect warm weather over the next few days before temperatures drop on Sunday.

“We are expecting extreme fire weather warnings hot gusty conditions before the cold front moves through,” he said.

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It’s a different story elsewhere in the country this weekend, with thunderstorms expected in parts of Western Australia and northern NSW.

The weather bureau is warning of severe storms in the northern rivers and northern tablelands regions of NSW, with possible damaging winds and large hailstones.

Thunderstorms are also forecast for much of eastern and southeastern Queensland, with severe weather warnings for Brisbane and on the Sunshine Coast, as well as several regional areas including the Darling Downs.

Hines said the stormy weather, expected to continue over the next month, wasn’t unusual for this time of year as conditions were “ripe for thunderstorm activity”.

“We’re getting longer days, warmer days. That heating is one of the things that provides the fuel for [storms] to develop, alongside humidity,” he said. “There have been very humid conditions from the tropics and around the equator.”

Another factor driving the stormy weather is the shifting of the Southern Annular Mode (SAM) into a positive phase. The SAM climate driver refers to a belt of strong westerly winds that blow around the south pole.

When it shifts into a “positive phase”, the SAM contracts and moves away into the Southern Ocean, it loses its influence on Australian weather, Hines said.

“When we’re in this positive phase, and those strong westerly winds move away from us, it opens the door for easterly winds on to eastern parts of the country,” Hines said.

“And it’s the easterly winds which often come in carrying a lot of humidity from the Coral Sea – from warm waters to the east and north east of Australia.”

Brisbane was drenched by more than 50mm of rain in an hour on Wednesday night, and Hines said Queensland would continue to bear the brunt of the thunderstorm activity over the next week.

Forecasters say it will be an average cyclone season in Queensland with at least one to make landfall this summer, but the severity of the storm system may be higher than usual.

Queensland has also been dealing with bushfires after heavy rain earlier this year provided plenty of fuel. People have been warned to prepare for possible fires if they have not yet been affected by the summer storm cells ripping across the state.

“The outlook for the next couple of months where we haven’t seen that rainfall, conditions are still ripe for very dangerous bushfires to occur,” meteorologist Kimba Wong told reporters on Thursday.

Queensland’s police deputy commissioner and state disaster coordinator, Shane Chelepy, said more than 1.25m hectares of land had burned since July.

There have been no deaths, but one residence was destroyed in Forsayth, in the state’s gulf country, in a blaze earlier this week.