[2] The season officially started on 1 November, however the first system, Cyclone Jasper, would not be active until 4 December, when it crossed into the basin as a tropical low from the South Pacific.

[29] Jasper rapidly intensified into a Category 3 severe tropical cyclone,[6] due to being in an environment with warm sea surface temperatures and low wind shear.

[47] Anggrek remained nearly stationary due to weak steering ridges to the north and southwest, the system generated upwelling, causing sea surface temperatures to decrease.

[48] Despite that, Anggrek steadily re-intensified,[49] and after entering favourable conditions on 24 January, became a Category 3 severe tropical cyclone, with estimated maximum 10-minute sustained winds of 150 km/h (90 mph), and a central barometric pressure of 968 hPa (28.59 inHg).

[53] On 7 January, the BoM noted the possibility of a tropical low forming near the north Kimberley, as a monsoon trough was expected to develop along the Top End.

[74] The JTWC began monitoring the remnants of Kirrily for potential regeneration as the system developed a partially exposed low-level circulation centre (LLCC).

[78] By 2 February, the JTWC discontinued their advisories again, as the storm accelerated inland with the rainbands unraveling and warming cloud tops,[79] until it was last noted on the BoM tropical cyclone outlooks by the next day.

[80] Before the storm made landfall on 24 January, the BoM issued cyclone warnings for Townsville, Mackay, Bowen, the Whitsunday Islands, which extended inland to Charters Towers.

[83] The next day, the BoM began monitoring the low as it was developing in the eastern portion of the basin, about 125 km (80 mi) to the northeast of Kgari in Queensland, Australia.

[86] Environmental conditions were assessed as being marginally conducive for tropical cyclogenesis, with warm sea surface temperatures near 29–30 °C (84–86 °F) and low vertical wind shear.

[94] By 15 February, at 14:30 UTC, the JTWC issued a TCFA, noting that the system was in a favourable environment with low wind shear and sea surface temperatures exceeding 29–30 °C (84–86 °F).

[89] By 21 February, the remnants of Lincoln turned westward into the offshore of the Kimberley coast and began to re-organise, resulting deep convection to the north.

[104] With an increase in convective banding on the southern of the cyclone's circulation,[105] the JTWC re-initiated advisories on the storm approximately 446 km (275 mi) northeast of Learmonth at 03:00 UTC on 22 February.

[108] The storm then crossed just south of Coral Bay on the Australian northwestern coastline just after 12:00 UTC that day, before moving inland across Gascoyne and dissipating shortly afterward.

[113] An increased monsoon flow over the Indian Ocean towards Indonesia prompted the agency to report that the tropical low was forming on 4 March, within an unfavourable environment for further development.

[122] The LLCC started to re–develop with deep convective bands wrapping into it, the JTWC re-initiated advisories approximately 341 km (210 mi) northwest of Learmonth at 03:00 UTC on 20 March.

[125] A pinhole eye briefly emerged on infrared and visible satellite imagery as a ragged feature at the cyclone's centre, surrounded by well-defined rainbands.

[126] Neville reached peak intensity at 06:00 UTC the following day as a high-end Category 4 severe tropical cyclone, with ten-minute sustained winds estimated at 175 km/h (110 mph), and a central barometric pressure of 952 hPa (28.11 inHg).

[131] Not long afterward, the storm began to deteriorate due to cooler waters, increasing vertical wind, and dry air entrainment.

[146][147] Gradually approaching the southwestern coast of the Gulf of Carpentaria,[148] the JTWC indicated that one-minute sustained winds had reached 185 km/h (115 mph), equivalent to a Category 3 major hurricane on the SSHWS.

[157] On 12 March, the BoM started to monitor a possible tropical low within the monsoon trough off the eastern Top End in the Gulf of Carpentaria, designating it as 10U.

[162][163] The JTWC assessed environmental conditions as being favourable for tropical cyclogenesis, with good poleward outflow and sea surface temperatures near 30 to 31 °C (86 to 88 °F) being offset by the effects of low to moderate vertical wind shear.

[164] Convective activity began organising into a symmetrical circulation, which prompted the JTWC to issue a TCFA on the disturbance as it tracked southwestwards into a favourable environment.

[165][166] By 5 April, the JTWC initiated advisories on the system and classified it as Tropical Cyclone 21S, about 642 km (400 mi) northwest of Learmonth, Western Australia.

[171][172] By the following day, the storm had undergone rapid intensification to attain its peak strength with sustained winds of 205 km/h (125 mph)—equivalent to a Category 5 severe tropical cyclone—and an estimated central pressure of 933 hPa (27.55 inHg).

[179][180] By the following day, the JTWC subsequently issued their final advisory on the system, as its gale-force winds soon became confined to the southern quadrant as the low became devoid of deep convection, leaving the LLLC exposed.

[182] On 8 April, the BoM reported that a small Tropical low had form within the monsoon trough in the northern Coral Sea near Louisiade Archipelago, and predesignated it as 13U.

[188] Paul featured a ragged central dense overcast and soon became sufficiently organised, obscuring the LLCC, with the BoM upgrading the storm to a Category 2 tropical cyclone.

[204][205] The United States' Joint Typhoon Warning Center (JTWC) reported that Cyclone Djoungou entered the Australian region after crossing the 90th meridian east from the South-West Indian Ocean basin at 18:00 UTC on 19 February, located approximately 1,271 kilometres (790 mi) to the west-southwest of Learmonth, Western Australia.

[210] Once formed, the low may contribute to a strengthening of the southeasterly winds to the south that will extend towards the southern Queensland coast, until they determine that it will not develop into a tropical cyclogenesis on 18 April.