A summary of the broadscale tropical circulation from 70°E to 180°, for the six months May to October 2005, is presented. The previous season (Nov 2004 - April 2005) was described as ENSO – neutral, although it did have some of the characteristics that are typical of weak El Niño events. Some of these indicators lingered for a short while into this period, but overall the period May to October 2005 is best described as being in a neutral ENSO phase. Towards the end of the period, there was some evidence of the Maritime Continent region becoming the broad focus of tropical convection. Throughout the season, sea-surface temperatures in the eastern near-equatorial Pacific were near average. The warmest waters of the Pacific were located close to the near-equatorial date-line, rather then the climatological location of the northwest Pacific. Most of the Northwest Pacific and Australian continent mean sea-level pressures were above average, with mostly close to average tropical convection. Outgoing long wave radiation and mean sea-level pressure over India indicate above average convection associated with the monsoon. Several active convective phases of the Madden-Julian Oscillation (MJO) were observed in the region during the season. The periodicity remained close to 45 days. A total of 18 tropical cyclones (13 typhoons) developed during the period, less than the mean (27) for the Darwin Regional Specialised Meteorological Centre (RSMC) area. All of these formed in the northwest Pacific.
Shaik et al. (Sun,) studied this question.