Monthly climate

Climate developments in February 2004

SPCZ was further south than usual

Above average rainfall in parts of Fiji, Vanuatu and the Southern Cook Islands

An extensive region of below average rainfall from Western Kiribati to Pitcairn Island

The Southwest Pacific OLR/rainfall anomaly pattern changed again, withthe February patterns almost opposite that of January. The SPCZ was located further south than usual in many areas, extending east-southeast from the Solomon Islands toward Fiji, across to Samoa, and over the Southern Cook Islands. Rainfall was above average over much of the SPCZ affected region, with anomalies exceeding 125% of normal over much of Fiji and in the Southern Cook Islands. There were 25 days with rainfall at both Rarotonga Airport and Bora Bora (Society Islands). February was also extremely wet with strong westerly winds over much of New Zealand’s North Island, many sites recording their wettest and windiest February on record. High intensity rainfall occurred over parts of Vanuatu during the passage of tropical cyclone ‘Ivy’ (25-26th February), with Bauerfield recording 544 mm in 48 hours, and 115 mm in 12 hours.

A large region of suppressed convection and below average rainfall (generally 75% or less of normal) affected the region from Western Kiribati spreading southeast to the Tuamotu Islands and Pitcairn Island. Other smaller regions of suppressed convection and generally below average rainfall occurred over the southern Coral Sea and New Caledonia and Niue. February was the 12th consecutive month with below average rainfall in many parts of Eastern Kiribati. Mean air temperatures exceeded 1.5°C above average in parts of New Caledonia and were 0.5-0.9°C above average in French Polynesia.

Climate extremes in February 2004

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 February 2004 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.