Severe thunderstorms with destructive winds, heavy rain and large hailstones are set to lash parts of Queensland on Thursday afternoon and tomorrow, the Bureau of Meteorology (BOM) says.
The BOM issued a severe thunderstorm warnings on Thursday afternoon for the Central West, Maranoa and Warrego, Central Highlands and Coalfields and Channel Country forecast districts.
Senior forecaster Kimba Wong said "unseasonable" rainfall of up to 50 millimetres could fall in isolated areas across the state's central and southern interior, south of Blackall down through the Warrego region.
"If we do see those severe storms develop, they do bring the risk of damaging wind gusts, large hail and heavy rainfall that may lead to flash flooding," Ms Wong said.
"We could see quite unseasonably significant rainfall of … 25 to 50 millimetres … in some areas, which is pretty uncommon for September.
"With thunderstorms, or a couple of repeat rounds of thunderstorms, we could see higher falls in a couple of locations as well, so certainly a bit of a big day for rainfall in the interior today."
Ms Wong said the severe weather is being caused by a cold front associated with a low-pressure system.
"We've got a trough and frontal system moving across eastern parts of the continent at the moment and that's tied into a low-pressure centre that's over the southern states at the moment," she said.
"Also being reinforced … by an upper trough so that's lending to quite unstable conditions in the interior today and of course, all of these systems are gradually making their way eastward tomorrow."
South-east to feel effects on Friday
The system is forecast to move over south-east Queensland tomorrow.
"South of about Bundaberg … the eastern Darling Downs and the south-east coast is the highest chance of seeing that severe storm activity tomorrow," Ms Wong said.
"Especially in the morning, probably some rain … across the south-east, that should clear off the coast by lunchtime or early afternoon.
"Then a redevelopment of showers and thunderstorms is expected for the afternoon and with that thunderstorm development, we do have a risk of severe storms.
"The main risk, if we do see those severe storms developing, would be the damaging winds and large hail, not so much the heavy rainfall as the storms themselves should be moving pretty quickly."
Ms Wong said the rainfall is likely to lead to localised, renewed river rises in already-flooded catchments.
"We do have a number of flood warnings still current across southern Queensland and we do have this rainfall moving across those flooded catchments, so there is a chance that these showers and storms may exacerbate the ongoing flooding we've got in these areas," she said.
She said conditions will ease on Saturday with "finer conditions" expected for the weekend.
