Eight to ten named tropical cyclones are expected to form in the Southwest Pacific basin between November and April.
Analysis by forecasting centres across the Southwest Pacific shows tropical cyclone activity is expected to higher around the Coral Sea and west of the International Date Line, and lower further east, reports NIWA.
New Caledonia, Fiji, Vanuatu and Tonga may experience two or more cyclones during the season, while three or four severe cyclones of Category 3 or higher, are expected anywhere across the region during the season that starts next month and lasts until the end of April.
Oceanic and atmospheric forecasts for ENSO (El Niño-Southern Oscillation) indicate La Niña conditions are expected to develop by summer. At present, sea surface temperature anomalies across the central and eastern equatorial Pacific Ocean and atmospheric circulation patterns over French Polynesia and northern Australia indicate conditions are ENSO-neutral, but leaning toward La Niña.
If La Niña conditions develop, they are likely to result in a significant change from normal tropical cyclone activity in many Pacific Islands.
Islands on the fringe of the north Coral Sea, including Papua New Guinea, the Solomon Islands, Vanuatu, New Caledonia and Tonga may experience slightly increased activity. Reduced activity is expected in some islands, especially those east of 160°W longitude, including the Cook Islands, the Marquesas and French Polynesia.
Tropical cyclones are categorised in strength from 1 to 5, with 5 being the most intense. For the coming season, about four storms are anticipated to reach at least Category 3, with mean wind speeds of at least 118 km/h.