Monthly climate
Climate developments in February 2003
SPCZ produces enhanced convection from Western Kiribati to Pitcairn
Suppressed convection from Papua New-Guinea to Niue
The SPCZ was generally displaced further north and east than average, with enhanced convection over much of the region from Western Kiribati southeast to Pitcairn Island. An equally large area of enhanced convection also occurred further west, over Indonesia and much of Australia. The frequency of equatorial surface westerlies weakened even further in February, reaching their lowest frequency at Tarawa (15% of observations) since May 2002.
February rainfall was at least 125% of average (and approximately 200 mm, or more) over a broad region from Western Kiribati, southeast to Pitcairn Island, including Tokelau, parts of the Cook Islands, and the Tuamotu Islands of French Polynesia.
A large region of suppressed convection occurred from Papua New-Guinea to Niue, including the Solomon Islands, Vanuatu, New Caledonia, Tuvalu, Fiji, Tonga, and Samoa where rainfall totals were less than 75% of average in most areas. Rainfall was less than 50% of average throughout much of Vanuatu, and Tonga.
New temperature records were set in Fiji. Temperatures were generally around average during the day in most places, whereas night time temperatures were generally below average. Some new rainfall records were set in New Caledonia and Tonga.
Climate extremes in February 2003
| Country | Location | Rainfall (mm) | % of average | Comments |
|---|---|---|---|---|
| Western Kiribati | Beru | 529 | 468 | Extremely High |
| Fiji | Nadi | 59 | 20 | Low |
| Vanuatu | Port Villa | 49 | 18 | Extremely Low |
| New Caledonia | Poindimie | 102 | 27 | Record Low |
| New Caledonia | Moue | 47 | 29 | Record Low |
| Australia | Norfolk Island | 10 | 12 | Extremely Low |
| Tonga | Nuku’alofa | 17 | 7 | Record Low |
| Tonga | Fua’amotu Airport | 30 | 14 | Record Low |
| Country | Location | Max Air Temp (°C) | Date | Comments |
|---|---|---|---|---|
| Fiji | Labasa | 34.7 | 7th | Record High |
| Country | Location | Min Air Temp (°C) | Date | Comments |
|---|---|---|---|---|
| Fiji | Navua | 19.5 | 3rd | Record Low |
Outgoing Long-wave Radiation (OLR) anomalies, in Wm-2 , for February 2003 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 February 2003 position of the South Pacific Convergence Zone (SPCZ), as identified from total rainfall, is indicated by the solid green line. The average climatological position of the SPCZ is identified by the dashed green line. Data source: NOAA-CIRES Climate Diagnostics Center.
Tropical cyclone update
We are now in the peak period of the Southwest Pacific tropical cyclone season, and there have been six tropical cyclones so far. ‘Dovi’, which occurred from 5–10 February, developed east of Samoa and tracked southwest to pass east of Niue on the 9th, then tracked southeast, with estimated maximum sustained wind speeds of 240 km/h (hurricane force). ‘Erica’, which is the most recent occurrence, tracked southeast in the western Coral Sea area off the Queensland coast of Australia from 4–6 March, with estimated maximum sustained wind speeds of 65 km/h (gale force).
The April issue of the ICU will provide an update on information relating to any occurrences of tropical cyclones in our forecast region of the Southwest Pacific.