The Bureau of Meteorology has warned up to 60 mm of rain could fall across the Lasseter and southern Simpson districts on Sunday as a cloud band strengthens over central Australia.
It is expected heavy downpours could trigger flash flooding.
The Walungurru region, which receives 270.8 mm of rain on average each year, has recorded 59 mm in the 24 hours to 9 a.m.
Some 100 mm of rain could fall over the warning area in the next 24 hours, the bureau said.
Other areas in the firing line include Kulgera, Papunya, Hermannsburg, Curtin Springs, Finke, Watarrka, Santa Teresa and Titjikala.
The bureau said catchments were likely to become progressively saturated this weekend, with a separate flood watch alert in effect for areas south of Elliott.
The heavy rain is expected to slowly clear from the west from Monday.
It comes as rain continues to hammer much of Australia’s east coast on Sunday, with residents in Sydney’s west told to evacuate their homes as the Hawkesbury Nepean Valley faces its worst flood threat in 60 years.
