Forecast validation

Forecast validation

Forecast period: September to November

Average to above average rainfall was expected in a band from Vanuatu, across Fiji, southeast to the Southern Cooks, the SPCZ being more active than usual in this region. Below average rainfalls were forecast for a broad area from Tuvalu to the Marquesas, including the Austral, Society and Tuamotu Islands of French Polynesia. Near average rainfalls were expected in most other parts of the tropical South West Pacific, although uncertainties were high for Kiribati.

This scenario was correct for many islands between 5 and 15°S, including New Caledonia and Fiji. However, rainfall was lower than expected for most other regions, especially Tonga, Niue, and the Southern Cook Islands, where below average rainfall resulted when average to above average rainfall was expected. Average or above average rainfall resulted over much of French Polynesia when average to below average rainfall was expected. The overall ‘hit rate’ for the September to November rainfall outlook was 50%.