2021/22 REGIONAL SPECIALIZED METEOROLOGICAL

CENTRE- NADI TROPICAL CYCLONE SEASONAL OUTLOOK

FOR OTHER PACIFIC COUNTRIES

FOUR TO SIX TROPICAL CYCLONES

TC TINO

Tropical Cyclone Seasonal Outlook for Pacific Island Countries

Figure 1.

Predicted number of tropical cyclones in each Pacific Island Countries EEZ during the 2021-

2022 season.

Figure 2.

Predicted number of Severe Tropical Cyclones for the Pacific Island Countries EEZ during the

2021-2022

Figure 3.

Tropical cyclone Risk for the Pacific Island Countries during the 2021-2022 TC Season in

comparison to climatology

Figure 4.

Severe Tropical Cyclone Risk for the Pacific Island Countries during the 2021-2022 TC Season

in comparison to climatology.

Figure 5.

2021-2022 Nadi- Regional Specialized Meteorological Centre (RSMC) Area of Responsibility

(AoR) Tropical Cyclone Seasonal Outlook

Detailed Outlook

The prediction of tropical cyclone activities are closely associated with the status of the El Niño

Southern Oscillation (ENSO) before the beginning of the new tropical cyclone season, which is

from May to September period. Neutral conditions were present in the tropical Pacific, while most

of the global climate models favor the development of a weak to boarder line moderate La Niña

event towards the end of 2021. These further influenced the selection of analogue seasons.

Based on the above methodology, seven (7) analogue seasons were identified with similar climate

state and expected condition during this tropical cyclone season. The analogue seasons includes

1974-75, 1984-85, 1995-96, 2008-09, 2011-12, 2016-17 and 2020-21 seasons (Table 1 and

Annex). Note that the selection of analogue seasons is limited due to availability of high-quality

satellite data from the 1969-70 season. Enhanced high quality tropical cyclone best track data from

the Southern Hemisphere Tropical Cyclone Portal were used for tropical cyclone analysis.

Once analysis of tropical cyclone counts in the analogue seasons are completed, it is concluded that

four to six (4 – 6) tropical cyclones are likely to occur in the Nadi- Regional Specialized

Meteorological Centre (RSMC) Tropical Cyclone Centre (TCC) Area of Responsibility (AoR)

(Figure 5). On average, around seven tropical cyclones affect Nadi- RSMC region a season. For

this season, it is predicted to have an average or below average tropical cyclone activity. For severe

tropical cyclone, on average around three severe tropical cyclone affect Nadi RSMC, each season.

This season is likely to have an average or below average number of severe tropical cyclones.

Table 1: Tropical cyclone numbers in the Nadi-RSMC AoR in the seven analogue seasons

Seasons Total Number of Tropical

Cyclones (Category 1 to 5)

Number of Severe Tropical

Cyclones (Category 3 to 5)

1974-75 5 3

1984-85 9 5

1995-96 4 1

2008-09 6 0

2011-12 3 1

2016-17 2 1

2020-21 6 3

Average (rounded-off) 5 2

Average tropical cyclone activity is likely to the west of International Dateline in the RSMC Nadi-

TCC AoR this season with around three to five (3 – 5) tropical cyclones likely to occur in this

region. One to three are likely to be severe tropical cyclones, which is close to the normal number

of severe tropical cyclones for this region.

On average around four tropical cyclones occur east of International Dateline in the RSMC-Nadi

TCC AoR every season. However, it is expected that this area will have reduced tropical cyclone

activity this season with one to three (1 – 3) tropical cyclones likely. The risk of severe tropical

cyclone is reduced to the east of Dateline.

Table 2: TC (Cat 1-5) occurrence risks during 2021-22 season in comparison to climatology

Country Climatology Analogue

Seasons

Risk

Solomon Islands 1.7 0.6 Reduced

New Caledonia 2.8 2.4 Normal

Vanuatu 1.9 1.6 Normal

Fiji 2.1 1.9 Normal

Tuvalu 0.4 0.3 Normal

Wallis & Futuna 0.5 0.3 Reduced

Tokelau 0.1 0.0 Reduced

Samoa 0.3 0.1 Reduced

American Samoa 0.6 0.0 Reduced

Tonga 1.8 1.7 Normal

Niue 0.7 0.6 Normal

Northern Cook Islands 0.5 0.0 Reduced

Southern Cook Islands 1.0 0.6 Reduced

Society Islands 0.5 0.0 Reduced

Austral Islands 0.6 0.0 Reduced

Tuamotu Archipelago/Gambier Islands 0.4 0.0 Reduced

Pitcairn Islands 0.1 0.0 Reduced

Marquesas 0.0 0.0 Unlikely

Kiribati 0.0 0.0 Unlikely

Table 3: Severe TC (Cat 3-5) risks during 2021-22 season in comparison to climatology

Country Climatology Analogue

Seasons

Risk

Solomon Islands 0.6 0.1 Reduced

New Caledonia 1.3 1.0 Normal

Vanuatu 0.9 0.7 Normal

Fiji 0.9 1.0 Normal

Wallis & Futuna 0.2 0.0 Reduced

Tokelau 0.1 0.0 Reduced

Samoa 0.2 0.0 Reduced

American Samoa 0.0 0.0 Unlikely

Tonga 0.5 0.3 Reduced

Niue 0.2 0.0 Reduced

Northern Cook Islands 0.2 0.0 Reduced

Southern Cook Islands 0.3 0.0 Reduced

Society Islands 0.2 0.0 Reduced

Austral Islands 0.2 0.0 Reduced

Tuamotu Archipelago/Gambier Islands 0.1 0.0 Reduced

Tuvalu 0.1 0.0 Reduced

Pitcairn Islands 0.0 0.0 Unlikely

Marquesas 0.0 0.0 Unlikely

Kiribati 0.0 0.0 Unlikely

End…