Australian tropical cyclone season outlook

Pacific outlook

The 2014–15 tropical cyclone season has ended

The next tropical cyclone season outlook is scheduled for release on Tuesday 13 October 2015.

2014–15 tropical cyclone review

The 2014–15 Australian tropical cyclone outlook, published in October 2014 predicted an average to below average number of tropical cyclones.

Tropical cyclone season summary

Seven tropical cyclones formed or moved into the Australian region and four made landfall on the Australian continent:

  • Seven tropical cyclones is below the long-term average of eleven
  • Four cyclones crossing the Australian coast is equal to the long-term average for cyclones making landfall.
Tropical cyclone tracks in the Australian region during the 2014–15 tropical cyclone season
Figure 1: Tropical cyclone tracks for the 2014–15 season
See also: Historical Australian region cyclone tracks

This is the first time in at least 35 seasons that all cyclones in the Australian region have reached severe tropical cyclone strength (category 3 or above).

The first tropical cyclone to make landfall was on 20 February 2014. This is unusually late in the season for the first cyclone to make landfall:

  • The last time the first crossing was so late in the season in Australia was 29 February 1988, when tropical cyclone Charlie crossed the coast near Townsville
  • The first coastal crossing has only occurred later than this twice in the past 50 years (1969–70 and 1987–88).

On 20 February 2015, two severe tropical cyclones made landfall over the Australian coast within hours of each other. This was the first time in Bureau records that two severe tropical cyclones have crossed the Australian coast on the same day.

Each cyclone in brief

Tropical cyclone Kate

  • Developed on 24 December 2014 in the Indian Ocean
  • First tropical cyclone to develop over Australian waters in the 2014–15 season
  • Impacted the Cocos Islands
  • Estimated maximum wind speed of 165 km/h (category 4)
  • Did not cross the Australian mainland coast.

Tropical cyclone Lam

  • Developed in the Gulf of Carpentaria, tracked slowly westwards
  • Crossed the coast on 20 February 2015 southeast of Milingimbi, Northern Territory
  • Estimated maximum wind speed was 185 km/h (category 4)
  • First tropical cyclone to make landfall in the 2014–15 season.

Tropical cyclone Marcia

  • Developed to tropical cyclone strength in the Coral Sea
  • Crossed the coast on 20 February 2015 at Shoalwater Bay near Yeppoon, Queensland
  • Estimated maximum wind speed was 205 km/h (category 5)
  • Operational estimates suggested it crossed the coast as a category 5 cyclone

Tropical cyclone Olwyn

  • Affected much of the Western Australia west coast from 13 March 2015
  • Estimated maximum wind speed was 150 km/h (category 3)
  • Crossed the coast on XX March 2015 as a category 3 cyclone

Tropical cyclone Nathan

  • Formed over the Coral Sea
  • Long-lived system, active for 18 days 9–27 March 2015
  • Estimated maximum wind speed was 165 km/h (category 4)
  • Crossed the Australian coastline three times in March 2015:
    • Cape York, Queensland, on 20 March
    • Northeast Arnhem Land, Northern Territory, on 22 March
    • Between Goulburn Island and Maningrida, Northern Territory, on 24 March.

Tropical cyclone Ikola

  • Moved into the Australian region on 3 April 2015
  • Did not make landfall
  • Estimated max wind speed was 175 km/h (category 4).

Tropical cyclone Quang

  • Final storm to form in the Australian area
  • Formed off the northwest coast on 28 April 2015
  • Estimated maximum wind speed was 195km/h (category 4)
  • Crossed the coast as a tropical low on 1 May 2015 (subject to change  after post-event analysis is complete).

Further information

Tropical cyclone strengths in this document are operational assessments and may change in post-analysis.
The Australian tropical cyclone season runs between 1 November and 30 April.

In an average season, the eastern region has around four tropical cyclones, of which one may cross the coast (~25%). The northern region typically has three, of which two typically cross the coast (~75%) and the western region has seven of which two (~30%) usually cross the coast.

The long-term average number of cyclones for the Australian region (eleven) is calculated over 44 seasons: 1969–70 to 2013–14. The highest number of cyclones to occur in one season is 18 in 1973–74 and 1983–84, and the lowest is five in 1987–88, during which only one tropical cyclone crossed the coast.

El Niño and La Ni ña influence the Bureau’s tropical cyclone outlook:

  • An average to below-average tropical cyclone season for Australia is consistent with El Niño-like conditions in the tropical Pacific Ocean late last year.
  • During periods when central Pacific Ocean temperatures are warmer than average (El Niño or near-El Niño), the focus of tropical cyclone activity shifts away from the Coral and Timor seas. This results in the Australian region generally experiencing fewer tropical cyclones than usual.
  • During El Niño years the first tropical cyclone of the season to make landfall over Australia typically occurs later in the season when compared with neutral or La Ni ña years.

Past Australian tropical cyclone season outlooks

Cyclone impacts

Before a tropical cyclone forms it is difficult to predict its exact strength and path, including whether it will make landfall. Along the east and west coasts fewer than half of the cyclones impact onshore areas, with the majority staying out to sea. Conversely, along the north coast more than half of the cyclones impact the coast. 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. The Bureau's flood warning services are an integral part of the response to tropical cyclones.

During the cyclone season, ensure you are well informed of any warnings from the Bureau of Meteorology and instructions from local Emergency Services authorities.

Diagram of storm tide height

Emergency services agencies

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 of the El Niño-Southern Oscillation (ENSO), respectively.

The July, August and September SOI and NINO3.4 values were used in making the Australian Tropical Cyclone Outlook.

2014 July August September
SOI -3.0 -11.4 -7.5
NINO3.4 SST 0.18 °C 0.20 °C 0.45 °C

The current status of ENSO can be viewed via the Bureau's ENSO Wrap-up. At the beginning of the 2014-15 tropical cyclone season the tropical Pacific was near El Niño thresholds, which has influenced this year's Tropical Cyclone Outlook. Sea surface temperatures in the NINO3.4 region have been warmer than average for several months and the Southern Oscillation Index has been consistently negative since early July (sustained negative values of -8 or below can be an indication that an El Niño is developing). Typically when the Pacific approaches or exceeds El Niño thresholds, the Australian region experiences less tropical cyclone activity.

Over the entire Australian Region, this statistical relationship has proven to be highly accurate, or a skilful way to forecast tropical cyclone activity. However, across the various sub Regions this relationship, and thus forecast skill, can vary. Some regions have much higher forecast skill than others. The Northwestern sub-region has good skill, while the Western and Eastern regions both have low skill and the Northern region has very low skill.

Further information