Forecasters say a very moist and unstable air mass will extend over the northern half of the state, and the focus for storm activity and heavy falls will gradually shift north with an upper trough over the next few days.

The Mount Isa forecast for Tuesday is partly cloudy with a high (70%) chance of showers, most likely in the morning and afternoon and the chance of thunderstorms. 

Similar conditions are expected Wednesday and Thursday though the chance of rain gradually decreases to 50%.

The official Isa Airport gauge registered 11.8mm on Sunday bringing the January total to 132.8mm which is already over twice the January 2016 total with half the month still remaining.

Meanwhile in Cloncurry had its wettest day of the year so far on Sunday. Water spilled over the spillway in Chinaman Dam after 56.8mm was recorded causing the Flinders Hwy to be temporarily cut off between Cloncurry and Julia Creek.

There are flood warnings for the Norman, Leichhardt and Cloncurry rivers.

Rainfall totals of 50-100 mm were recorded across the Gulf Rivers catchments in the 24 hours to 9am Sunday with a further 50-80 mm of rainfall recorded after 9am. Minor flooding is occurring at Yappar River and moderate flooding is occurring at Lower Walker Creek in the Norman River catchment.

Areas of heavy rainfall and thunderstorms are expected across the Gulf Rivers over the next few days.

River levels are rising throughout the Leichhardt River but currently remain below the minor flood level. Further rises are expected over the next few days.

Minor flooding is likely on the Cloncurry River. The river at Cloncurry was at 2.98m and falling Monday morning. Renewed river level rises at Cloncurry were likely to exceed the minor flood level (3m) into Monday.

Roads closed include Dajarra to Mount Isa and Cloncurry, and Cloncurry-Four Ways.