Forecast validation

Forecast validation

Forecast period: September to November 2004

Enhanced convection was expected with above average rainfall over Eastern and Western Kiribati, with areas of average or above average rainfall in the Tuamotu Islands and Pitcairn Island. Suppressed convection with average or below average rainfall was expected in New Caledonia, Fiji, Tonga, and the Marquesas Islands. Rainfall was expected to be near average elsewhere in the region.

The outcome differed greatly from what was forecast, with above average rainfall (higher than expected) over the Solomon Islands and Tuvalu, and from Niue southeast to the Austral Islands. Rainfall was also above average and higher than expected in the Marquesas Islands. Rainfall was below average (and lower than expected) over Western and Eastern Kiribati and Tokelau, as well as Vanuatu, Wallis and Futuna, Samoa, and the Northern Cook Islands. Totals were near average elsewhere. The overall ‘hit’ rate for the September to November 2004 rainfall outlook was about 35% due to uncertainties in the strength of the climate response to the weak El Niño during the forecast period.