South Australia's Premier says there has been an extreme rainfall event in Pukatja on the state's remote Anangu Pitjantjatjara Yankunytjatjara (APY) Lands.
Steven Marshall said the town — formerly known as Ernabella — had a "massive deluge" overnight, but the full details are yet unknown.
"This is a very remote part of our state and it's even less accessible now with the Stuart Highway cut off," Mr Marshall said.
The Bureau of Meteorology said 105.8mm of rain fell in Pukatja in the 24 hours to 9am, about half the town's normal annual rainfall.
A severe weather warning for heavy rainfall and a flood watch warning are current for the north-west and north-east pastoral districts.
Last week, a major emergency declaration was issued for flooding and storm damage in South Australia's north after some parts received up to 200 millimetres of rain.
While the declaration was initially for 14 days, Mr Marshall said it would likely be "in place for the foreseeable future".
"There are no vehicles travelling north of Glendambo at the moment but we have been able to, essentially, charter every available aircraft in the state at the moment to help with the overall response to this new major emergency declaration," he said.
The Defence Force began flying supplies and groceries to Coober Pedy yesterday and more flights are expected on Tuesday.
Further south, the town of Port Augusta was also inundated last night, with more than 50mm of rain causing flash flooding.
Bureau of Meteorology meteorologist Jonathan Fischer said another 50–80 millimetres was forecast in the north of South Australia on Tuesday but then the weather should clear.
"But it will take some time for this water to flow down through these inland watercourses, infiltrate and evaporate, so we may need generalised flood warnings to continue for some of the larger inland river systems, including the Cooper Creek, and that may be extended to the Warburton River as well," he said.
Concern for missing man
Mr Marshall said he had not been told of any fatalities linked to the floods, but raised concerns for a man missing in the north-eastern outback since last Tuesday.
Queensland man Christopher Taylor, 40, was last seen on foot at the Innamincka Trading Post.
Police said he had been camping in the area with a friend when he walked off.
"This man has now been missing for quite some time," the Premier said.
"We don't know how well provisioned he may or may not have been.
"We're hoping there's a positive outcome.
"We're hoping there may be some good news coming soon, but obviously this a major concern for SAPOL."
Mr Taylor is described as 178cm tall with a black beard and dark hair.
He was last seen wearing a dark-coloured T-shirt, shorts and thongs.
