Summary

Issued 4 August 2017

• The El Niño-Southern Oscillation (ENSO) remains neutral. All climate models surveyed by the Bureau indicate the tropical Pacific Ocean is likely to stay ENSO-neutral for the rest of 2017.
• In the last fortnight, a weak Madden-Julian Oscillation (MJO) tracked eastwards across the Maritime Continent, before moving into the western Pacific Ocean and strengthening. During that period, six tropical cyclones developed in the northwest Pacific Ocean and South China Sea. A majority of the international climate models indicate the MJO signal will rapidly weaken while over the Pacific Ocean and become indiscernible in the coming week.
• In July there was significantly enhanced convection over the Philippines, Indonesia, Palau, western Federated States of Micronesia, northern Papua New Guinea and northern Solomon Islands. The Intertropical Convergence Zone (ITCZ) further east was close to its average July position but marginally suppressed near the Date Line. In the south Pacific, the South Pacific Convergence Zone (SPCZ) extended further east than normal and was enhanced over northern Papua New Guinea and northern Solomon Islands. Convection was suppressed in the vicinity of New Caledonia, Vanuatu, Fiji, Samoa and the southern Cook Islands.
• According to the four-week Coral Bleaching outlook from 30 July, bleaching is expected to develop in the Yap State region and around Kapingamarangi Island in the southern Pohnpei State region of the Federated States Micronesia.
• Seasonal rainfall outlooks for August to October 2017 favour below normal rainfall for southeast Papua New Guinea. Model outlooks differ elsewhere.