Article
BAMOS February 2026
11
Both events are examples of seemingly“ weak” weather systems, such as upper-level cyclones, resulting in severe impacts. Mesoscale processes like topography may have played a role in enhancing rainfall during these events, but have yet to be studied in detail.
Tropical Cyclone Luana in the northwest and a second heatwave in the southeast( late January 2026)
Tropical Cyclone Luana made landfall north of Broome on 24 January as a Category 2 system. Luana was a large cyclone that brought exceptionally widespread moisture and rainfall inland, particularly in Derby, which recorded 191.2 mm of rainfall within 24 hours.
Around the same time, a second heatwave hit the southeast. On 27 January, central Melbourne recorded a maximum of 42.7 ° C and the nearby Laverton station 45.6 ° C. Victoria also set all-time maximum temperature records of 48.9 ° C at Hopetoun Airport and Walpeup. Temperatures rapidly dropped in coastal Victoria on 28 January, although northern regions of Victoria and inland New South Wales were denied this reprieve and continued to experience multiple days above 40 ° C. Meanwhile, South Australia experienced extreme heat, with temperatures exceeding 50 ° C at Andamooka on the 29th and Port Augusta on the 30th. Maree also set a new national record with five consecutive days above 48 ° C.
Were these two contrasting events connected?
It might seem unusual to suggest that wet weather in the north and hot weather in the south are physically connected. But research has shown that tropical cyclones in northern Australia are often associated with heatwaves in the southeast. This occurs when upper-level divergent winds above the cyclone push the jet stream poleward, reinforcing the high-pressure system and associated extreme heat to the southeast.
Figure 2 displays this plausible connection between Tropical Cyclone Luana and the heatwave in the southeast. On 27 January, Ex-Tropical Cyclone Luana was located over central Western Australia, bringing abundant tropical moisture inland as it moved southward. This was connected to a striking band of cloud oriented northwest to southeast, indicative of a strong cold front. To the east was a largely cloud-free region of extreme heat, created by descending air within the high-pressure system.
The tropical cyclone-heatwave link illustrated here generalises to some extent for any kind of strong, organised tropical convection that occurs near the jet stream, such as monsoon lows or mesoscale convective systems, although tropical cyclones moving into the midlatitudes are the most direct example of this. The impacts of such events can be felt far to the east of where the tropical system is located.
The early-to-mid summer of 2025-26 was characterised by contrasting extremes between the north and south. It is worth noting that the link between wet conditions in the north and hot and dry conditions in the south was physical and not simply due to random chance. With the exception of some local extreme rainfall events, southern Australia continues to be dry, making drought a real possibility in the coming months.
Figure 2: Himawari-8 visible satellite imagery for 2 pm on 27 January 2026. Credit: https:// himawari8. nict. go. jp /