Monthly climate
Climate developments in April 2003
SPCZ further north, from Tuvalu to the Society Islands
Enhanced convection no longer exists over Kiribati
The SPCZ was displaced further north than average, with enhanced convection over parts of Tuvalu, Tokelau, and the Society Islands of French Polynesia. April rainfall was at least 125% of average (and 300 mm or more in places) over much of this region. Rainfall totals were also 125% or more of average in southern Vanuatu, parts of New Caledonia, the Kermadec Islands northeast of New Zealand, and areas of the Austral Islands in southern French Polynesia.
Rainfall was variable over Fiji. Enhanced convection was also associated with the Inter-Tropical Convergence Zone (ITCZ) in latitudes 8-10° north of the equator.
The last week of April was unsettled with flooding and heavy rainfall totalling over 200 mm in some of Fiji’s Central Division areas, as well as in parts of New Caledonia (288 mm at Ouanaham on the 23rd).
The large region of suppressed convection (associated with rainfall totals generally less than 75% of average) extended further west in April, driven by the equatorial surface easterlies, which occurred in 91% of observations at Tarawa (Western Kiribati), extending from Western Kiribati well to the east of the Marquesas Islands of northern French Polynesia. Suppressed convection also occurred over the Solomon Islands.
Air temperatures were at least 0.5°C above average throughout much of the tropical Southwest Pacific, as far east as Pitcairn Island, but near average in New Caledonia.
Climate extremes in April 2003
| Country | Location | Rainfall (mm) | % of average | Comments |
|---|---|---|---|---|
| Tuvalu | Nanumea | 565 | 225 | Record High |
| French Polynesia | Tuamotu, Hereheretue | 290 | 229 | Record High |
| Country | Location | Rainfall (mm) | Date | Comments |
|---|---|---|---|---|
| Fiji | Tokotoko, Navua | 229 | 30th> | Record 1-Day High |
| Country | Location | Min Air Temp (°C) | Date | Comments |
|---|---|---|---|---|
| Fiji | Penang | 17.4 | 17th | Record Low |
Outgoing Long-wave Radiation (OLR) anomalies, in Wm-2 are represented by shaded areas, and rainfall percentage of average, shown by numbers. High radiation levels (yellow) are typically associated with clearer skies and lower rainfall, while cloudy conditions lower the OLR (blue) and typically mean higher rainfalls. The April 2003 position of the South Pacific Convergence Zone (SPCZ), as identified from total rainfall, is indicated by the solid green line. The average position of the SPCZ is identified by the dashed green line. Data source: NOAA-CIRES Climate Diagnostics Center.