After an already active start to the tropical cyclone season in the South Pacific, we will see another system developing this week, coming close the main group of Fijian islands. 

A tropical disturbance (identified as TD02F) located to the north of Vanuatu is forecast to deepen and intensify over the coming days, possibly reaching a category 1 or 2 tropical cyclone on Monday or Tuesday. The next Tropical Cyclone to be named by the Fiji Meteorological Service will be called Mal. The consensus across computer models is that this system will track east, and then southeast, towards Fiji.

Figure 1: A forecast track map for the tropical low issued by the Fiji Meteorological Service on Sunday. 

The low can be seen as a relatively disorganised mass of cloud and convection at the moment (as seen in the video below). Warm sea surface temperatures, light vertical wind shear and ample moisture, will provide favourable conditions for this system to become more organised into a tropical cyclone by mid-week. 

Video: Himawari Satellite imagery showing the relatively disorganised mass of cloud and convection to the north of Vanuatu on Sunday morning. 

The system is forecast to track offshore to the west of Viti Levu, Fiji’s most populous island. However, strong northeast, turning north and then northwest winds should blow over the Yasawa, western Viti Levu (including Nadi) and Kadavu islands. With a relatively rapid passage, gales could develop first in the north from Tuesday, and clear the south by the end of Wednesday. Heavy rainfall will also affect the islands, with potential for 100-200mm over western Viti Levu in the coming days, which is usually relatively dry in the predominant southeasterly trades that blow over the region. 

Figure 2: Strong northerly winds blowing over the western Fiji early on Wednesday morning. 

Figure 3: Accumulated rainfall over the Fiji region until Thursday afternoon. 

This follows an eventful start of the South Pacific Tropical Cyclone season after Severe Tropical Cyclone Lola became the earliest Category 5 Southern Hemisphere tropical cyclone on record, impacting Vanuatu in October. 

For the latest update on the development of the current system, please refer to: http://www.met.gov.fj/