Climate and Oceans Support Program in the Pacific (COSPPac) Bulletin

Issued 10 March 2023

  • La Niña has weakened in the tropical Pacific Ocean and is likely near its end.
  • The Madden-Julian Oscillation (MJO) moved slowly in and around the Western Pacific in the past week, as the result of interaction with an Equatorial Rossby Wave.
  • The Intertropical Convergence Zone (ITCZ) was more active in the eastern Pacific around 150°W, while the South Pacific Convergence Zone (SPCZ) displaced southwest over Solomon Islands, Vanuatu, Fiji and Tonga, indicating the La Niña event.
  • Sea surface temperatures (SST) in February 2023 were cooler than average across much of the tropical Pacific Ocean, extending from around 165°E in a broadening wedge to the South American coastline.
  • The Coral bleaching status for 03 March 2023 shows 'Alert Level 2' extending southeastward from southeast PNG, southern Solomon Islands, western Vanuatu, southeast Fiji and Tonga.
  • For March-May 2023, the models unanimously agree on above normal rainfall for Palau, Guam, CNMI, most of FSM, RMI, the southeast of PNG's EEZ, most of Solomon Islands, New Caledonia, Vanuatu, much of Fiji, most of Tonga, Niue, and southern French Polynesia. The models are also unanimous in showing that below normal rainfall is likely or very likely for southern parts of central and eastern Kiribati, most of Tuvalu, Tokelau, Wallis and Futuna, American Samoa, northern Cook Islands and northern French Polynesia.
  • The ACCESS-S weekly tropical cyclone forecast model shows a significantly increased risk between 15 and 21 March around the eastern Australia, Coral Sea Region, Vanuatu and New Caledonia. For the northwest Pacific, there is significantly increased risk for the Philippines, Palau and western FSM area between 15 and 28 March.