Tropical Cyclone Outlook

Eight to fourteen Tropical Cyclones (TCs) are likely in the Regional Specialised Meteorological Centre Nadi-Tropical Cyclone Centre (RSMC Nadi-TCC) area of responsibility (AoR) between November 2023-April 2024.
On average, around seven TCs affect the RSMC Nadi-TCC AoR a season. Thus, this season is predicted to have above average TC activity.
Around four TCs per season on average affect west of the Dateline in the RSMC-Nadi TCC AoR and around three to the east. This season, four to six TCs are expected to affect west of the Dateline, which means near average or above average TC risk. To the east, six to nine TCs are likely, which is an above average risk.
Three severe TCs, that is, Category 3 or higher intensity, on average affect the RSMC Nadi-TCC AoR a season. This season is likely to have five to seven severe TCs, which is an above average risk.
Two to four severe TCs are expected to the west of Dateline (long-term average is 2), which is near average to above average risk. On the other hand, three to four severe TCs are likely to the east of Dateline (long-term average is 2), which is an above average risk.
While the TC season in the region is between November and April, occasionally cyclones have formed in October and May and rarely in September and June. Therefore, out of season TCs cannot be ruled out.
The peak TC season in the RMSC-Nadi TCC AoR is usually between January to March, but TCs can form at any time during the season.

Figure 1: Total number of TCs forecasted for the RSMC Nadi-TCC AoR.

Figure 2. Number of severe TCs forecasted for the RSMC Nadi-TCC AoR.

TC activities in the Pacific Island region are closely associated with the El Niño Southern Oscillation (ENSO), which is a fluctuation of oceanic and atmospheric condition between the eastern and western tropical Pacific Ocean.
An El Niño event is established in the tropical Pacific, which is expected to persist through the 2023-24 TC season.
To predict the outlook for the 2023-24 TC season, analogue seasons were identified, that is, seasons in the past (from 1980) with similar background climate. These seasons were 1982-83, 1987-88, 1991-92, 1997-98, 2009-10 and 2015-16.
The TCs season in southwest Pacific extend from November to April, with the peak TC activities normally experienced from January to March. However, TCs have occasionally occurred in this region during October and May, and rarely in September and June. One of the analogue seasons (1997-98) also had an out of season TC. Thus, out of season TCs are also possible this season.
Tropical disturbances or depressions that do not attain TC intensity can also cause strong winds/gusts, widespread rainfall, landslides and flooding.
Please contact the respective Pacific Island National Meteorological Service for detailed national level information.

Two to three tropical cyclones (TCs) are likely to pass through Fiji’s Exclusive Economic Zone during the 2023-24 TC season.
Of these, one to two TCs are likely to reach severe Category (Category 3-5).
There is equal risk of TCs affecting any part of the Fiji Group.
While the peak TC activities are usually from January to March, TCs can form at anytime during the season. Out of season TCs cannot be ruled out.
It does not take a direct hit or a severe TC to cause considerable damage or life-threatening weather. Tropical disturbances or depressions that do not attain TC intensity can also cause strong winds/gusts, widespread heavy rainfall, landslides and flooding.
All communities should remain alert and prepared throughout the TC season and take heed of all advisories whenever it is issued.

Figure 1: Total number of TCs forecasted for the Fiji region.

Figure 2. Number of severe TCs forecasted for the Fiji region.

To predict the outlook for the 2023-24 TC season, analogue seasons were identified, that is, seasons in the past (from 1980) with similar background climate. These seasons were 1982-83, 1987-88, 1991-92, 1997-98, 2009-10 and 2015-16.
On average, around two TCs affect Fiji every season. Thus, there is an elevated risk of TCs to affect the Fiji region this season.
The TC season in the southwest Pacific extend from November to April, with the peak TC activities normally experienced from January to March. However, TCs have occasionally occurred in this region during October and May, and rarely in September and June. One of the analogue seasons (1997-98) also had an out of season TC. Thus, out of season TCs cannot be ruled out this season.
In the past, tropical depressions also had significant impact on Fiji, especially heavy rainfall and severe flooding. Thus, it is important to take heed of all-weather advisories seriously.