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

Issued 10 August 2026

• The El Niño has been underway since mid-June and continues to strengthen, with further intensification likely in the coming months.
• A moderate Madden-Julian Oscillation (MJO) signal is currently located in the Western Hemisphere with forecasts to continue active in the Western Pacific during early August.
• In July, the Intertropical Convergence Zone (ITCZ) was active along its climatological position. The South Pacific Convergence zone (SPCZ) was active and shifted north of its climatological position over the western Pacific.
• Sea surface temperatures (SSTs) for July were mostly near-normal to above-normal in most countries in the Pacific, with the highest on record SST deciles [11] along the equator over Kiribati (Phoenix and Line Islands) and much of the Marshall Islands. A patch of lowest on record SST decile was recorded in Tonga.
• The Coral bleaching Alert up to 31 July indicates areas of 'Alert Level 2' and 'Alert Level 1' along the equator over Kiribati (Phoenix and Line Islands) and over the Northern Mariana Islands (CNMI). The 4-Week Outlook to 17 August extends alert and warning conditions to Nauru, the Marshall Islands and the Northern Mariana Islands.
• For August to October 2026, the models agree that above normal rainfall is likely or very likely over CNMI, Guam, eastern FSM, RMI, Nauru, Kiribati (Gilbert, Phoenix, and northern Line Is.,), northern Tuvalu, northern Tokelau, and Pitcairn Islands. Below normal rainfall is likely or very likely for Palau, PNG, Kiribati (southern Line Is.), Solomon Islands, New Caledonia, Vanuatu, Fiji, Tonga, Niue, southern Tuvalu, Wallis and Futuna, Samoa, American Samoa, southern Tokelau, most of Cook Is., and northern French Polynesia.
• The weekly tropical cyclone forecasts from the ACCESS-S model shows increased risks in the north-western Pacific near Guam, and CNMI for the week of 08-21 August 2026.