Summary
An out of season unnamed tropical cyclone formed briefly over the western Solomon Sea. Impacts are unknown but it is likely that heavy rain and strong winds impacted the Rossel and Vanatinai (Tagula and Sudest) Islands in the southeast of the Louisiade Archipelago within Milne Bay Province of Papua New Guinea.
A tropical low formed on 27 June in the western Solomon Sea near Muyua Island in the far east of PNG. The low drifted to the south then southeast towards the Vanatinai (Tagula and Sudest) and Rossel Islands. Increased deep convection developed particularly in the overnight from 28-29 June to produce a tight band of deep convection about a compact centre. Category 1 tropical cyclone intensity was estimated from early on 29 June until late in the day.
Overnight from 29-30 June the tropical cyclone was affected by wind shear and weakening commenced. The system turned to the northwest. Despite brief increases in deep convection the system then weakened further, dissipating on 1 July.
21U was an example of a small system that both rapidly deepened then weakened.
The system was not named during operations but has been upgraded to a tropical cyclone upon reanalysis.
For more information see the Unnamed Tropical Cyclone 21U report (doc).
Track and Intensity (Time in UTC (AEST-10h))
