Posted 8th October 2017 for the Australian cyclone season 1st of November 2017 to 30th of April 2018. Updated 1st November 2017.
UPDATE: A La Nina watch is current. A La Nina event has a 65% chance of developing by January 2018. Should this develop it may increase the risk of Tropical Lows and Tropical Cyclones across the Australian region between January to April.
This season we are predicting a total of 11 cyclones to develop in the Australian region which is typically near average. Due to slightly above average ocean sea surface temperatures surrounding Northern and Eastern Australia, there is a higher chance that more cyclones will become severe – Category 3 or higher. Almost 50%, or 5 of the forecast 11 cyclones are predicted to develop into a severe category 3+ system. This produces a higher risk of destructive impacts to coastal regions in Australia. Also up to 5 of the 11 predicted cyclones could potentially cross the Australian coastline.
• Eastern region: Queensland coast, Coral Sea and Gulf of Carpentaria. A total of 4 cyclones with 2 possibly severe (category 3 or higher). 2 of these systems potentially crossing the Queensland coast with 1 along the Gulf Coast and 1 along the East Coast.
• Northern region: Northern Territory Coast, Arafura Sea. A total of 2 cyclones with 1 possibly severe (category 3 or higher). 1 system potentially crossing the NT coast.
• Western region: Western Australia Coast, Timor Sea, Joseph Bonaparte Gulf and Indian Ocean. A total of 5 cyclones with 2 possibly severe (category 3 or higher). 2 of these systems potentially crossing the WA coast.
• Tropical Lows: Up to 20 tropical lows are also forecast to develop across the Australian region with many of them impacting the mainland. Tropical lows are one of Northern Australia’s biggest rainfall producers during the wet season. Occasionally they also end up tracking further South into Central and Southern Australian regions. They bring widespread heavy rain, flooding and sometimes damaging winds. Its not uncommon for tropical lows to bring rainfall totals of 250 to 500mm from just one system given their slow moving nature and very high moisture levels.
***Please keep in mind that it only takes 1 severe cyclone to cross the coast causing significant widespread damage! The biggest threats are very heavy rain causing major flooding, sea surge causing coastal inundation and destructive winds causing property and infrastructure damage. All of these weather threats are potentially life threatening! We will provide a high number of cyclone forecasts and updates if required this season… just as we did with TC Debbie last year.***
• Eastern region QLD: Total number of cyclones 2 – Alfred and Debbie. Total number of coastal crossings 2 – Gulf and CQLD Coast. Total number of severe 1 – Debbie Cat 4.
• Northern region NT: Total number of cyclones 2 – Blanch and Frances. Total number of coastal crossings 1 – Tiwi Islands. Total number of severe 1 – Frances Cat 3.
• Western Region WA: Total number of cyclones 5 – Yvette, 22U, Caleb, Ernie, Greg. Total number of crossings 1 – Port Hedland. Total number of severe 1 – Ernie Cat 5.
• Tropical Lows: An Australian record number of 30 Tropical Lows were identified many which impacted Western Australia and the Northern Territory with heavy rainfall.