Australian meteorologists are closely watching a deep low-pressure system north of the Solomon Islands that may develop into the first tropical system to enter the Queensland monitoring zone in July in at least four decades.

The low is currently moving south-westwards and may enter Australia's eastern region either late on Tuesday or during Wednesday, according to the Bureau of Meteorology. The agency said the system is expected to develop further and could form into a tropical cyclone near the islands either on Wednesday or Thursday.

Possible tropical cyclone forms over the Solomon Islands. Credit:BoM

While the system is likely to "remain very far offshore and does not pose a threat to the Queensland coast", the bureau noted that the storm is forming well outside the official cyclone season that runs from November 1-April 30.

Blair Trewin, senior climatologist at the bureau, said that while it remains to be seen when and whether the system becomes a cyclone, a storm this late in the year is very rare.