Far north Queensland communities will spend Christmas Day on cyclone watch as a low pressure system threatens to bring potentially damaging weather.

The slow-moving system is hovering over the Northern Territory but whether it becomes the first cyclone of the season won't be clear until it reaches the Gulf of Carpentaria on Friday.

'The warmer and more shallow water of the gulf makes it conducive to cyclones but whether it forms or stays as a low, we'll just have to see,' Bureau of Meteorology forecaster Jess Carey told AAP.

'At this stage, there is a 20-50 per cent chance.'

The system would be named Stan or Tatiana if it becomes a cyclone.

Premier Annastacia Palaszczuk says remote communities are prepared for damaging weather.

'I want to reassure everyone that all the precautions are taking place,' she said.

However, it is unlikely the wet weather system will bring much-needed rain to drought-stricken central and western Queensland communities further south.

'It's a possibility but the modelling doesn't show it heading in that direction,' Mr Carey said.

A monsoonal trough dumped more than 100mm of rain in Cairns and the north tropical coast on Wednesday.

The BOM has issued a flood warning for coastal catchments north of Townsville, while areas including the Daintree are on flood watch.

AAP