After three seasons of below average cyclone activity, the 2002–03 season was slightly above average, featuring ten cyclones and seven severe tropical cyclones. One of the cyclones, Cyclone Erica, originated from the Australian region but later moved into the South Pacific, where it impacted New Caledonia. Throughout the season, a moderately warm El Niño–Southern Oscillation (ENSO) generated a shift of cyclone activity away from Australia and towards the open waters of the southern Pacific. As a result, the Southern Oscillation Index (SOI) between November 2002 and June 2003 was negative, averaging -7.2. Sea surface temperatures (SSTs) in the Pacific were above average; for most of the tropical regions, SSTs were above 29 °C (84 °C). At various times, Madden–Julian oscillation (MJO) pulses increased convective activity and thus cyclone development in the basin. Five pulses of the MJO and Equatorial Rossby waves (ER) were responsible for most of the cyclone activity during the season. Cyclone Zoe, the strongest cyclone of the season, was the only cyclone with no connection to any identified MJO or ER wave. By April, an easterly trade wind anomaly took place, signifying the end of the El Niño pattern that had persisted for much of the year.