Defeat to India in their tournament opener meant Australia finished second in Group A, so would be knocked out by Group B winners South Africa if their semi-final at the SCG is not completed.
Australia's hopes of retaining the Women's Twenty20 World Cup in a blockbuster final on Sunday could fall foul of the Sydney weather, with heavy rain threatening to wash out Thursday's semi-finals.
A shock loss to India in their tournament opener means Australia finished second in Group A, so would be knocked out by Group B winners South Africa if their semi-final clash at Sydney Cricket Ground (SCG) was not completed.
Unbeaten India take on England in the first of Thursday's semi-finals at the SCG and would progress to Sunday's final at the Melbourne Cricket Ground (MCG) if a minimum of 10 overs a side were not possible because of the weather.
Cricket Australia (CA) had spoken with the International Cricket Council about the possibility of moving the matches to a reserve day, but had been told it was not possible under tournament rules, CA chief Kevin Roberts said.
"It's not part of the playing conditions and we respect that," Roberts told Melbourne's SEN radio on Wednesday.
Stormy weather is forecast by the Bureau of Meteorology throughout Thursday at the SCG, with the chance of rain in the evening when Australia are scheduled to take on the South Africans ranging from 50% to 70%.
The loss to the tournament of the four-times champions and hosts would be a major blow to hopes that Sunday's final will attract a crowd in excess of 90,000 to the MCG.
The host's immediate priority is to fill the void created by all-rounder Ellyse Perry's exit from the tournament with a hamstring injury.
"We've got a few options that we're looking at to replace Ellysse," Australia captain Meg Lanning told reporters.
"Obviously we can't truly replace her, but we've got a number of different options to go with depending on the conditions."
South Africa are also fretting on the availability of all-rounder Marizanne Kapp, who suffered heart palpitation in Sunday's match against Pakistan and skipped training.
"A player's health is more important than a game," South Africa skipper Dane van Niekerk said.
"Whatever decision is made I am confident other players would step up and make sure she is not missed to much."
India will be hoping to improve their dismal 0-5 tournament record against England in a rematch of the 2018 semi-final in Antigua.
"After losing the last semi-final, as a team we realised that we have to work as a unit," India captain Harmanpreet Kaur said.
"We just need to keep doing the right things and just focus on the right things instead of worrying about the past."