Normal or below normal tropical cyclone (TC) activity was forecast for most islands in the southwest Pacific during the 2011/12 season.
February through April (the late season) is typically the most active part of the TC season, although some storms have occurred outside of this time frame in the past.
A total of five named storms have occurred since the start of the season in November 2011, and no named storms occurred in the Southwest Pacific basin during April 2012. This concludes the 2011/12 TC season, which has experienced well below normal activity.
On average, nine tropical cyclones occur each year for the southwest Pacific, and are grouped into classes ranging from 1 to 5, with 5 being the most dangerous. For the coming season, at least one cyclone is forecast to reach at least Category 3, with mean wind speeds of at least 64 knots or 118 km/h and one system may reach at least Category 4 strength, with mean wind speeds of at least 86 knots or 159 km/h.
The ICU TC forecast update indicates 8–10 named TCs are likely for whole season, with six to eight named storms forecast for the late season.
Places like Vanuatu and New Caledonia typically experience the greatest TC activity, with an average of about 3 or 4 TCs passing close to those countries each year (see Table, right for late season averages).
Near normal to below normal TC activity for the remainder of the 2011/12 season was forecast for most islands. Historical cyclone tracks indicate that TCs can affect parts of southwest French Polynesia, including the Society and Austral Islands, and the southern Cook Islands during La Niñas, especially late in the season.
In the situation where a TC develops outside of the normal season in the May - October period, these storms would be 'credited' to the preceding forecast period.
More details about TC forecasts and the science underpinning them can be found on our website. In the Pacific Islands, consult with your local meteorological service for tropical cyclone guidance.
The next regional TC forecast will be issued in October 2012.
