About four coastal impacts are expected during the 2025-2026 Australian Tropical Cyclone Season.

Sea surface temperature (SST) anomalies in the tropical Pacific NINO3.4 region have been slightly negative for most of 2025 but remain within the neutral range. Dynamic and Statistical models continue to indicate slightly negative anomalies until about January 2026, with a slow recovery to near zero anomalies
by April 2026.

The Australian Region tropical cyclone count (TCC) for the 2025-2026 tropical cyclone season is expected to be slightly above the most recent 30-year
average, with about 9 tropical cyclones. Of these, about 4 are expected to become Severe Tropical Cyclones (STC). Accumulated Cyclone Energy (ACE) is expected to be near the 30-year average over the NW region, below average over the northern region and above average over the NE region.

Link for the full report: 2025-2026 Australian Tropical Cyclone Season Outlook 

February 25, 2020. Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-NASA Suomi NPP satellite image of tropical cyclones Ferdinand and Esther as they passed over and near Australia.(The line across the left side of the image marks the edge of the swath between two satellite passes that occurred about 90 minutes apart.)

Image source: NASA Earth Observatory

For the 2024-2025 Tropical Cyclone Season, slightly above the 30-year average tropical cyclones are expected with about 9 expected to develop and about 4 becoming Severe Tropical Cyclones (STC). Accumulated Cyclone Energy (ACE) is forecast to be well above the 30-year average over the northeast region, but a little below average over the northern and northwestern regions. This TC Season, all regions will have about 5 coastal impacts.

Click here for the full 2024-2025 Australian Tropical Cyclone Season report.

Tropical Cyclone Billy over the NW  Shelf, December 30, 2008 (Satellite imagery from the NASA Earth Observatory)

The period from late 2023 to date (early May) has seen El Niño conditions (based on NINO3.4 detrended SST anomalies) decreasing into 2024 to be near the upper boundary of the neutralrange (‐0.8 to +0.8 degree threshold) in April. The expectation is that the NINO3.4 anomaly will continue to decrease over the coming months and remain negative through the coming NW Pacific TC Season.

The expected number of tropical cyclones (TC), tropical storm intensity or greater, over the NW Pacific region in the 2024 season is 20 which is below the long term (1969-2022) average of 24. The systems that form are expected to be of below average intensity with Accumulated Cyclone Energy (ACE) forecast to be 85% of the long-term average.

About 7-8 tropical cyclones are expected to affect the South China Sea, which is a little below average. The systems that form are expected to be of below average intensity when compared to the long-term average (ACE about 80% of normal.

Click here for more details on the OWS 2024 Northwest Pacific Tropical Cyclone Outlook.

Tropical Cyclones (TC) over the Australian Region will be below the long-term average, with about 7 TCs expected and about 4 becoming Severe Tropical Cyclones (STC). Accumulated Cyclone Energy (ACE) is expected to be slightly below the long-term average across the northwest and northern regions and near the long-term average over the northeastern region. Between 1-7 coastal impacts are expected across all regions.

The sea surface temperature (SST) anomalies in the NINO3.4 region have been increasing in recent months and have been above the El Niño threshold since June. Dynamic models have these anomalies continuing to increase until around the end of the year. Values then decrease early next year but remain above the El Niño threshold at the end of March.

For the full 2023/24 Tropical Cyclones Season Outlook report, click  HERE.

About 24 tropical cyclones (TC), tropical storm intensity or greater, are expected over the NW Pacific region in the 2023 Tropical Cyclone Season which is close to the long term (1970‐2022) average. About 17 systems are expected to reach typhoon strength which is slighlty above average. The overall intensity of the TCs should be above average (ACE 116% of normal).

In the South China Sea region, the number of TCs should be close to normal, around 9 in total with about 5 expected to reach typhoon strength.

There is a moderate risk (33%) of a TC affecting the Gulf of Thailand (Nov – Dec).

Download complete report:  2023 NW Pacific TC Outlook

At present negative sea surface temperatures (SST) anomalies meeting the La Niña threshold persist in the NINO3.4 region. Dynamic models have these anomalies persisting for the next month values rising from December, with nearly all models moving anomalies back into the neutral range by February. These conditions are expected to result in a slightly above average number of Tropical Cyclones (TC) over the Australian Region, with about 10 expected and 3-4 becoming Severe Tropical Cyclones (STC). Accumulated Cyclone Energy (ACE) is expected to be slightly below the long-term average across the northwest region and below the long-term average over the northern and northeastern regions.

For the whole Australian region (0 – 30S and 105 ‐ 160E), the total number of TCs in the Australian region should be slightly above the long-term average (although more significantly above the average for recent years), approximately 10 in total (range 6-12). Some of these may affect more than one area, with about 6-7 coastal impacts expected. The Accumulated Cyclone Energy index (ACE) is below the long-term average although close to average for recent years.

For the Northwest Shelf and Timor Sea (0 ‐ 30S and 105 ‐ 125E), about 5 TCs (range 3-9) are expected which is slightly above average. Expected season will be from mid November to late April with 3 to 4 TCs may be expected to cross the coast.

Download full report: 2022/23 Australian TC Season Outlook

The period of 2020 to date has seen weak positive El Nino conditions over the central Pacific but below the threshold (+0.8). Most of the models show the current NINO3.4 anomaly decreasing during the next few months, with the dynamical model average becoming negative by July and remaining negative until at least November. However, they remain in the neutral range. Several of the models indicate values falling more rapidly over the coming months with La Nina conditions developing during the northern hemisphere summer (June-July-August) then persisting through the rest of the year.
Based on the above conditions, the expected number of tropical cyclones (TC), tropical storm intensity or greater, over the NW Pacific region in the 2020 season is 25 which is slightly above the long term (1970‐2016) average. The systems that form are expected to be of near average intensity with Accumulated Cyclone Energy (ACE) 109% of the long term average.
About 11 tropical cyclones are expected to affect the South China Sea, which is also slightly above average. The systems that form are expected to be of above average intensity when compared to the long‐term average (ACE is 132% of normal).

Offshore Weather Services is a proud Bronze Sponsor of the 2nd International Workshop on Waves, Storm Surges and Coastal Hazards on 10-15 November 2020 at the Sheraton Hotel, Melbourne, Australia. The 2nd International Workshop is hosted by the University of Melbourne and incorporates the 16th International Waves Workshop. The workshop on waves occurs every two years and usually in North America so it is a real privilege to be able to support the international workshop locally.

OWS Managing Director Peter Wellby, Research and Development Manager Dave Duncalf and Numerical Modelling Specialist Dr Simon Caine will be attending the workshop together with other ocean wave researchers around the globe.

OWS, as a private forecasting company providing weather and marine forecasts to the Oil & Gas Industry for 17 years, recognizes the role and impact of waves on offshore operations and supports the workshop on waves, storm surges and coastal hazards. OWS has wave modelling capabilities and run its own high resolution wave models in-house.

For inquiries on OWS wave modelling capabilities, please email ows@offshoreweather.com.au.

For more details on the Workshop, please follow the links below:

2nd International Workshop on Waves, Storm Surges and Coastal Hazards

16th International Waves Workshop

Typhoon HAGIBIS remains on track to hit Japan. Although HAGIBIS has started to weaken today 11 October, the typhoon’s powerful winds are expected to cause widespread damage, high waves and storm surges along the coastal areas.

HAGIBIS is expected to make its landfall on Saturday 12 October near Tokyo, an area still recovering from the damages of Typhoon FAXAI a month ago. Typhoon FAXAI caused three casualties, injured dozens and left 930,000 people without power when it hit eastern Japan in September.

Hagibis rapidly intensified into a Super Typhoon on October 7 when the storm’s winds increased by 85kt (100mph/160kph) in 24 hours and is claimed to be the fastest rate of intensification ever observed on Earth.

JMA’s forecast chief, Yasushi Kajihara, said Hagibis resembled a typhoon that hit Tokyo in 1958 that flooded hundreds of thousands of homes and left 1,200 people dead.