Melbourne's weather will determine whether Queensland or NSW can train under the Telstra Dome roof ahead of Wednesday night's Origin decider.
Both have their final run at the venue tomorrow afternoon and both are keen to have the roof closed to simulate match conditions. But Dome officials won't close the roof if sunshine is reaching the playing surface.
Queensland's session is 2:30pm with the Blues at 4:30. NSW is likely to have at least the latter part of its under the roof if Melbourne produces a sunny day.