Climate Summary

Issued on 05 October 2018

• The Bureau's ENSO Outlook remains at El Niño ALERT, indicating there is approximately a 70% chance of El Niño occurring in 2018 around triple the normal likelihood. In the Indian Ocean there are signs that a positive Indian Ocean Dipole (IOD) is underway.
• For the month of October, the OLR and TRMM anomaly maps suggest ITCZ was weaker than normal west of about 160°W, especially close to the equator between about 150°E and the Dateline. Over the central to eastern Pacific the ITCZ was shifted slightly southward towards the equator. The SPCZ was enhanced and a little southwest of normal between Vanuatu, Samoa, the southern Cook Islands and the far southeast of French Polynesia. It was weaker than normal west of Vanuatu.
• Models outlooks for November 2018 to January 2019 indicate below normal rainfall for Palau, FSM, north and southeast Papua New Guinea, Solomon Islands, Vanuatu, Fiji, south Tuvalu, Tonga, Samoa, Niue and southern Cook Islands. Above normal rainfall is favoured for north Tuvalu, Kiribati and northern Cook Islands. Models are less emphatic elsewhere.
• Above average tropical cyclone activity is expected in the western North Pacific in 2018. Three or four tropical cyclones of tropical storm intensity or higher are likely to pass nearby Guam, the Commonwealth of the Northern Mariana Islands (CNMI), Yap or Palau by the end of this year. In the Southwest Pacific, regional-scale tropical cyclone outlooks for the upcoming November 2018 to April 2019 season favour near average (7-11) numbers of tropical cyclones, following the very early TC Liua that formed in September. Tropical cyclone activity is expected to be lower than normal around the northern and eastern Coral Sea margin and elevated east of the International Date Line. For the week 8-14 or even up to 21 November 2018 the chances of tropical cyclone occurrence for the Pacific region is low. The Vanuatu, New Caledonia and Fiji region continue to remain active for this week.