Island Climate Update 22 - July 2002

23 March 2007 - 12:46pm

Science Centres: Climate

July

Monthly climate

ENSO & SST

Forecast validation

Three-month outlook

Feature article

Data sources

Feature article
Southern Oscillation Index (SOI) adopted from Bureau of Meteorology, Australia. Click to enlarge Sub Surface Temperature along the Equator for May 2002 (adapted from TOA/TRITON). Click to enlarge Sub Surface Temperature along the Equator for June 2002 (adapted from TOA/TRITON). Click to enlarge El Niño Update More progress towards the evolution of an El Niño in the last month Probabilities have increased to 85% for an El Niño event affecting the whole of the Southwest Pacific by September this year.

Forecast validation
Forecast validation Forecast period: April to June 2002 Rainfall was projected to be above average in the Western and Eastern Kiribati and Vanuatu, and average to above average in New Caledonia, Fiji, Niue and Pitcairn Island. Average to below average rainfall was expected for much of the region from the Solomon Islands east to the Marquesas including the Northern Cooks, and central French Polynesia. Average rainfall was forecast for other areas. Rainfall was as expected for many of the forecast areas. However, it was higher than forecast in Samoa and the Marquesas and Austral Islands.

ENSO & SST
ENSO and Sea Surface Temperatures Equatorial Pacific Ocean up to +1.5°C warmer than average El Niño likely if conditions persist In the tropical central Pacific, a band of anomalously warm water (+1.5°C above average) extends from Western Kiribati towards the coast of South America. An area of the Pacific which is also very much warmer than average lies southeast of Pitcairn Island (+2.0°C above average). Generally, most of the Southwest Pacific is warmer than average ( +1.0 to 1.5°C).

July
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region. Number 22 – 11 July 2002 June’s Climate: The South Pacific Convergence Zone (SPCZ) extended east from the Solomon Islands toward Tuvalu. However, it was virtually non-existent further east in the Southwest Pacific. A large area of enhanced convection with areas of above average rainfall affected the region from the Solomon Islands west to Papua-New Guinea.

Monthly climate
Enhanced convection over Papua New Guinea and the Solomon Islands Below average rainfall from Fiji to the Southern Cook Islands In June, the SPCZ extended east from the Solomon Islands toward Tuvalu, being displaced north of its mean position in that region. However, it was virtually non- existent further east in the Southwest Pacific. A large area of enhanced convection with areas of above average rainfall affected the region from the Solomon Islands west to Papua-New Guinea. In the north, the ITCZ was further south than usual, enhancing rainfall and cloudiness over parts of Kiribati.

Three-month outlook
Rainfall outlook for July to September 2002 Above average rainfall in equatorial latitudes from Nauru to Kiribati Average to above average rainfall for the Solomon Islands, Vanuatu and Tuvalu Average to below average rainfall in New Caledonia, Fiji, Samoa Tokelaus and Marquesas Mainly around average rainfall in other areas In the Western Pacific, the South Pacific Convergence Zone (SPCZ) extended east from Solomon Islands to Tuvalu and was virtually non-exsistent further east during June.

Data sources
Sources of South Pacific rainfall data This bulletin is a multi-national project with important collaboration from the following Pacific nations: American Samoa Australia Cook Islands Fiji French Polynesia Kiribati New Caledonia New Zealand Niue Papua New Guinea Pitcairn Island Samoa Solomon Islands Tokelau Tonga Tuvalu Vanuatu Requests for Pacific island climate data should be directed to the Meteorological Services concerned. Acknowledgements This bulletin is made possible with financial support from the New Zealand Agency for International Development (NZAID), Wellington, New Zealand, wi