2012–2013 South Pacific Tropical Cyclone Season Outlook

Odds favour a near average tropical cyclone season for the South Pacific

  • Near average tropical cyclone activity is the most likely scenario for the full South Pacific region.
  • There is a tendency for average to below average cyclone activity in the western region of the South Pacific.
  • Climate indicators which affect tropical cyclone activity show that:
    • the tropical Pacific Ocean is currently neutral (neither El Niño nor La Niña);
    • near-El Niño conditions have been present in 2012 and have been considered in this outlook.

The typical Australian tropical cyclone season:

  • runs between 1 November and 30 April;
  • averages around 15 tropical cyclones;
  • always has some risk of tropical cyclones impacting upon Pacific Islands Countries.

Chance of above average tropical cyclone (TC) activity

Region Summary Chance of
above average		 Long-term average
number of TCs*		 Forecast
skill
Whole South Pacific region Near average 53% 15 Low
Western region Average to below average 35% 8 High
Eastern region Near average 55% 11 Low

*averages may change when the dataset is updated.

The current, neutral state of the El Niño–Southern Oscillation (ENSO) would historically suggest the South Pacific region as a whole would experience near average tropical cyclone activity during the coming season. However, warmer than average sea surface temperatures in the central equatorial Pacific in July, August and September suggests slightly reduced odds of above average (slightly increased odds of below average) tropical cyclone activity in the western region of the South Pacific this season. Historically, the model has shown high skill in the west. This outlook is for the southern hemisphere tropical cyclone season which is usually considered to be between 1 November and 30 April.
Related information: Tropical cyclone average conditions.

Cyclone Impacts

Before a tropical cyclone forms it is difficult to predict its exact strength and path, including whether it will make landfall. Tropical cyclones which remain out to sea can still cause storm surges, gales and areas of heavy/flooding rainfall over land.

Even after a tropical cyclone has passed, or has decayed below tropical cyclone strength, significant flooding may occur. The impacts of flooding may be more widespread than the area impacted by the cyclones damaging winds..

During the cyclone season, ensure you are well informed of any warnings from local agencies and instructions from local emergency services authorities.

See also:

Pacific tropical cyclones portal screen capture showing cyclone history

Pacific tropical cyclones portal tracks since 1969

About the Outlooks

This outlook is produced using statistical relationships between tropical cyclone numbers and two indicators: the Southern Oscillation Index (SOI) and the Niño3.4 sea surface temperature index (NINO3.4 SST). These indicators provide a measure of the strength of the atmospheric and oceanic state, respectively.

The July, August and September SOI and NINO3.4 values were used in making the South Pacific tropical cyclone season outlook.

2012 July August September
SOI -1.7 -5.0 +2.7
NINO3.4 SST 0.53°C 0.73°C 0.45°C

The current status of ENSO can be viewed via the Bureau's ENSO Wrap-up. Tropical Pacific Ocean temperatures showed signs of a developing El Niño until late September. However, as of mid-October, conditions have generally eased away from El Niño thresholds. Despite this shift, the tropical Pacific remains warmer than average. Other El Niño–Southern Oscillation (ENSO) indicators, such as the trade winds and tropical cloud patterns also remain at values typical of neutral conditions. The monthly Southern Oscillation Index (SOI) value for September was +2.7: El Niño would be indicated by sustained (i.e. a few months) SOI values below -8.

Research references

Model: Kuleshov, Y., L. Qi, R. Fawcett and D. Jones, 2009: Improving preparedness to natural hazards: Tropical cyclone prediction for the Southern Hemisphere, in Advances in Geosciences, 12 Ocean Science, (Ed. Gan, J.), World Scientific Publishing, Singapore, 127-143.

Data: Kuleshov, Y., R. Fawcett, L. Qi, B. Trewin, D. Jones, J. McBride and H. Ramsay, 2010: Trends in tropical cyclones in the South Indian Ocean and the South Pacific Ocean, Journal of Geophysical Research 115, D01101, doi:10.1029/2009JD012372.

Further Information

This Outlook provides general guidance for the South Pacific region. For specific guidance for an individual country, please contact their National Meteorological and Hydrologic Service.

Map showing South Pacific tropical cyclone outlook regions.

The regional boundaries used by the three Tropical Cyclone Warning Centres: Perth, Darwin and Brisbane

South Pacific tropical cyclone outlook region bounds

Region Top Bottom Left Right
Whole South Pacific region 5° S 40° S 142.5° E 120° W
Western region 5° S 40° S 142.5° E 165° E
Eastern region 5° S 40° S 165° E 120° W

Related links

Definitions

Past tropical cyclone outlooks: 2010-11, 2011-12