The weather bureau is closely watching a “complex system” sitting off the Queensland coast on Monday morning, with intense rainfall and life-threatening flash flooding likely if the trough tracks slightly west.
The Bureau of Meteorology said there was a chance of heavy rainfall leading to flash flooding possible for Hervey Bay, the Sunshine Coast and coastal fringes of the Gold Coast areas, with the possibility of 150mm in six hours.
In addition, intense rainfall that may lead to “dangerous and life-threatening” flash flooding is possible for communities east of Maryborough and Noosa Heads, with isolated six-hourly rainfall totals of up to 250mm.
Overnight, the low remained offshore, keeping severe weather away from the coast.
Forecaster Matt Marshall said whether communities were impacted by heavy rainfall on Tuesday depended on how the low moves during the day.
“If the trough pushes a little closer to the coast, a lot of those heavier falls are going to be affecting those coastal areas … But if it moves just a little bit further offshore, all those heavy falls will be over the water and we won’t see many significant impacts on the land,” Mr Marshall said.
“It’s all hanging in the balance with the precise movement of this trough, that’s where the uncertainty is at the moment … If it does move a little bit to the west, we’ll see impacts along those coastal areas.”
Mr Marshall said Brisbane would largely escape the heavy rainfall if it did fall.
Rain has already lashed parts of the Queensland coast, with Mt Wolvi on the Sunshine Coast recording 42mm since 9am on Sunday, Tin Can Bay with 41mm, and Ghost Hill with 34mm.
Mr Marshall said a dangerous surf warning was also active for the Queensland coast, stretching from Agnes Water all the way down to the Gold Coast.
“There’s a swell that’s been whipped up as well as strong winds associated with that whole system so conditions are not that great on the beaches at the moment,” he said.
“From today, that’s extending all the way up to Agnes Water along to the Gold Coast waters. That’s contracting a little south tomorrow and conditions will ease around Agnes Water but will still be impacting from Fraser Coast south.”