Three-month outlook: July to September 2007
Rainfall outlook map for July to September 2007. (Click for enlargement)
The rainfall forecast for the Pacific region for the coming three months depicts La Niña like pattern.
Enhanced convection is expected over Samoa and the Northern Cook Islands where rainfall is expected to be above aveage.
A large region of near or above average rainfall is likely from Papua New Guinea to French Polynesia, including the Solomon Islands, Vanuatu, Walli and Futuna, Fiji, Tonga, Niue, the Southern Cook Islands, Tuamotu Islands, Society Islands, and the Austral Islands.
Suppressed convection is likely in the equatorial region of Western and Eastern Kiribati, where rainfall is forecast to be below average. Near or below average rainfall is expected over Tuvalu and Tokelau.
The rainfall forecast model skill is around moderate for this time of the year.
| Island group | Rainfall outlook | Outlook confidence |
|---|---|---|
| Samoa | 30:30:40 (Above) | Moderate |
| Northern Cook Islands | 30:25:45 (Above) | Moderate |
| Papua New Guinea | 20:40:40 (Near or above average) | Moderate |
| Solomon Islands | 20:40:40 (Near or above average) | Moderate |
| Vanuatu | 20:40:40 (Near or above average) | Moderate |
| Wallis and Futuna | 20:40:40 (Near or above average) | Moderate |
| Fiji | 20:40:40 (Near or above average) | Moderate |
| Tonga | 20:40:40 (Near or above average) | Moderate |
| Niue | 20:40:40 (Near or above average) | Moderate |
| Southern Cook Islands | 20:40:40 (Near or above average) | Moderate |
| Tuamotu Islands | 20:40:40 (Near or above average) | Moderate |
| Society Islands | 20:40:40 (Near or above average) | Moderate |
| Austral Islands | 20:40:40 (Near or above average)) | Moderate |
| New Caledonia | 25:40:35 (Near average) | Low – moderate |
| Marquesas Islands | 20:45:35 (Near average) | Moderate |
| Pitcairn Island | 30:40:30 (Near average) | Moderate |
| Tuvalu | 40:40:20 (Near or below average) | Moderate |
| Tokelau | 40:40:20 (Near or below average) | Moderate |
| Western Kiribati | 40:30:30 (Below) | Moderate |
| Eastern Kiribati | 40:30:30 (Below) | Moderate |
NOTE: Rainfall estimates for Pacific Islands for the next three months are given in the table. The tercile probabilities (e.g., 20:30:50) are derived from the interpretation of several global climate models. They correspond to the odds of the observed rainfall being in the lowest (driest) one third of the rainfall distribution, the middle one third, or the highest (wettest) one third of the distribution. On the long-term average, rainfall is equally likely (33% chance) in any tercile.