A woman and child clung to a tree after their car was swept off the road, while a road-train driver was stranded in his cab after his vehicle also fell victim to Queensland floodwaters.

Meanwhile, a tropical low in the Gulf of Carpentaria could intensify into a category 2 cyclone on Monday, with wind gusts of 130km/h, a storm tide, flooding and heavy rain on the cards.

A satellite image a captured on Saturday afternoon shows a slow-moving tropical low that threatens to develop into Cyclone Esther in the Gulf of Carpentaria near the Northern Territory-Queensland border. Credit:Bureau of Meteorology

In terms of the overnight rescues, the car in which the woman and child were travelling was swept off West Plain Creek Road in Sarina on the central Queensland coast just before 7pm on Saturday.

A Queensland Fire and Emergency Services spokesman said the pair clung to a tree in the floodwater before swift water rescue crews got them to safety.