Forecast validation: May to July 2009

A region of suppressed convection was forecast in the southwest Pacific encompassing Tokelau, Tuvalu, and the Northern Cook Islands, with below average rainfall expected for those areas during May – July 2009. Near to below average rainfall was expected for Eastern Kiribati and the Marquesas. Near normal rainfall was forecast for Pitcairn Island and Samoa. Enhanced convection was forecast for Papua New Guinea and Vanuatu, Fiji, Niue, and the Southern Cook Islands, with above average rainfall.

A region of suppressed convection was forecast in the southwest Pacific encompassing Tokelau, Tuvalu, and the Northern Cook Islands, with below average rainfall expected for those areas during May – July 2009. Near to below average rainfall was expected for Eastern Kiribati and the Marquesas. Near normal rainfall was forecast for Pitcairn Island and Samoa. Enhanced convection was forecast for Papua New Guinea and Vanuatu, Fiji, Niue, and the Southern Cook Islands, with above average rainfall. New Caledonia, Tonga, Wallis & Futuna, and the Austral Islands were expected to receive near or above average rainfall. No clear precipitation guidance was offered for the Western Kiribati, the Solomon Islands, the Tuamotu Archepelago and the Society Islands   The  May – July 2009 forecast validation was calculated for 13 island groups (two countries did not report rainfall values; four were forecast as climatology and were unscorable). The global island group ‘hit’ rate was 74%, 21% higher than average for May forecasts, and 13% higher than the average for all months combined. Rainfall was overprojected for Vanuatu and the Southern Cook Islands, while it was underprojected for Samoa.