The 2008–09 Australian region cyclone season was a near average tropical cyclone season. It officially started on 1 November 2008, and officially ended on 30 April 2009. This season was also the first time that the BoM implemented a "tropical cyclone year." The regional tropical cyclone operational plan defines a "tropical cyclone year" separately from a "tropical cyclone season"; the "tropical cyclone year" began on 1 July 2008 and ended on 30 June 2009.

The scope of the Australian region is limited to all areas south of the equator, east of 90°E and west of 160°E. This area includes Australia, Papua New Guinea, western parts of the Solomon Islands, East Timor and southern parts of Indonesia.

Tropical cyclones in this area are monitored by five Tropical Cyclone Warning Centres (TCWCs): the Australian Bureau of Meteorology in Perth, Darwin, and Brisbane; TCWC Jakarta in Indonesia; and TCWC Port Moresby in Papua New Guinea. The Joint Typhoon Warning Center issues unofficial warnings for the region, designating tropical depressions with the "S" suffix when they form west of 135°E, and the "P" suffix when they form east of 135°E. __TOC__

Seasonal forecasts

Bureau of Meteorology In October 2008 ahead of the season starting on 1 November, the tropical cyclone warning centres in Perth, Darwin and Brisbane issued a seasonal outlook for their area of responsibility, which urged people to prepare for possible tropical cyclones. Within each outlook factors such as the high values of the Southern Oscillation Index, near average sea surface temperatures and the neutral El Niño–Southern Oscillation conditions were taken into account. TCWC Perth predicted within their seasonal outlook that the North-Western subregion between 105°E and 130°E would see an early start to the season. They also predicted that between 5 - 7 tropical cyclones would occur in the region during the season compared to an average of about 5 and that there was a likelihood of two tropical cyclones and one severe tropical cyclone impacting Western Australia. TCWC Darwin predicted that there might be an early start to the season within the Timor Sea and slightly above average numbers of tropical cyclones around northern Australia. They also noted that there was an even chance of having a severe tropical cyclone in the region during the season. Within their outlook TCWC Brisbane predicted that there would be a high amount of activity within the Australian Monsoon, and that the chances of a repeat of the widespread flooding rains were not great due to their being no well-established La Nina.

Others During September 2008, the New Zealand National Institute of Water and Atmospheric Research (NIWA) and its partners issued a tropical cyclone outlook, for the South Pacific region between 135°E and 120°W.

On 26 September 2008 the New Zealand National Institute of Water & Atmospheric Research issued a seasonal forecast for the whole of the southern Pacific Ocean to the east of 150°E. They predicted that the 2008–09 South Pacific cyclone season would see an average risk of cyclones forming, which meant that 8-10 tropical cyclones with wind speeds greater than 35 knots would form east of 150°E.

Seasonal summary

Systems

Tropical Cyclone Anika

During 17 November TCWC Perth and TCWC Jakarta reported that Tropical Low 02U had developed within the monsoon trough about to the northeast of the Cocos Islands. During the next day the low quickly developed further as it was steered on a south-easterly course by an area of persisting north-westerly steering winds. TCWC Perth, TCWC Jakarta and the JTWC then reported early on 19 November that the low had developed into a weak tropical cyclone with Perth naming it Anika. On 20 November, Anika reached its peak intensity as a Category 2 cyclone with winds of 95 km/h (60 mph) and a pressure of 984 hPa. The intensification was the result of deep convection wrapping around the center of circulation and Dvorak Technique intensity estimates reaching T3.5. Cyclone Anika passed to the north of the Cocos Islands, and cyclone warnings were cancelled later that day. Later that day, it weakened to a Category 1 cyclone. As the storm tracked over cooler waters, it continued to weaken. By 21 November, the storm weakened to a tropical low due to increasing wind shear. The next day, the Anika dissipated over open waters.

Severe Tropical Cyclone Billy

On 17 December, a tropical low formed in the Arafura Sea north-west of Darwin in the Northern Territory. It moved into the Joseph Bonaparte Gulf and was very slow moving. On the night of 18 December it intensified into a Category 1 cyclone and was named Billy. On 20 December, Billy made landfall as a Category 2 cyclone approximately 65 kilometres north of Wyndham. After then, it weakened to a tropical low and moved slowly towards the southwest. It then moved off the coast just north of Kuri Bay and redeveloped into a tropical cyclone on 22 December as the storm turned to the north-north east. Late on 24 December, Billy began to rapidly intensify and reached Category 4 strength early on 25 December and became a typical annular cyclone. Later that same day, Billy weakened into a category 3 cyclone as it replaced its eyewall and TCWC Perth issued their final tropical cyclone advisory as the system was moving away from land. Billy weakened into a category 1 cyclone on 27 December and weakened into a tropical low on 28 December. Later that day, TCWC Perth issued their final advisory, as the system continued to weaken.

Two remote indigenous communities, Kalumburu and Oombulgurri were cut off by flood waters with roads and the airstrips closed.

Tropical Low 04U

On 20 December, an area of low pressure, associated with developing convection, formed about 1000 km (560 mi) east of Darwin in the Gulf of Carpentaria. The next day, the Bureau of Meteorology in Darwin designated the system as a tropical low. Banding features developed along the southern portion of the system and further development was anticipated as the low was located underneath an anticyclone. Around 5:26 a.m. local time on 23 December, the low made landfall near Port Roper, preventing further development of the storm. About 36 hours after landfall, the Australian Bureau of Meteorology issued their final advisory on the system as it dissipated over land.

Tropical Low 05U

On 23 December, TCWC Brisbane noted that a weak tropical low had formed within the Solomon Sea, about 1330 kilometres to the north east of Cairns. Over the next few days the low moved towards the south west into the Coral Sea.

Tropical Cyclone Charlotte

On 8 January, TCWC Darwin identified a Tropical Low in the southern Gulf of Carpentaria. The next day TCWC Brisbane begin to issue advisories on the low and issued Cyclone Watches for coastal communities between Aurukun on the Cape York Peninsula and the Northern Territory/Queensland border. On 11 January, the Tropical Low developed into Tropical Cyclone Charlotte, and on 12 January at 4:00am (AEST), crossed the coast near the Gilbert River Mouth with wind gusts of 120 km/h (70 mph).

Heavy rains, estimated at over 150 mm (5.9 in), from Tropical Cyclone Charlotte flooded at least 100 homes in low-lying areas on Cape York including Babinda, Mount Sophia and at Normanton. The rains also caused mudslides which, as described by an affected home-owner "...it's just mud, mud everywhere". The main road to Karumba was also cut off by flood waters. Damages caused by the storm were estimated to be at US$15 million.

Tropical Low 07U (05F)

On 11 January a tropical low formed in the Coral Sea. The winds peaked at . The low exited the basin and intensified into Tropical Depression 05F.

Tropical Cyclone Dominic

On 22 January, TCWC Perth noted that Tropical Low 08U had formed overland, to the north of Broome in North-West Australia. JTWC had upgrade this system become a significant tropical cyclone as "good". On 25 January at 11:15am (AWDT), TCWC Perth issued a Tropical Cyclone Warning for coastal areas from Wickham to Exmouth. Later that day, the JTWC issued a Tropical Cyclone Formation Alert as a tropical cyclone was likely to form within the following 48 hours. TCWC Perth begun issuing advisories for the developing tropical low and issued a tropical cyclone warning along the far western coastline of the Western Australia region. On 26 January, the system became Tropical Cyclone Dominic. Further intensification followed and Dominic was upgraded to a Category 2 cyclone several hours later. Morning of 27 January, Dominic made landfall just after 7am (AWDT) near Onslow. Later that day Dominic weakened to a Category 1 cyclone before weakening into a tropical low during the day. JTWC issued its last advisory on this system on 27 January as it continued to weaken inland.

The formation of Dominic in an area that produces significant amounts of oil resulted in numerous evacuations of offshore oil platforms. The platforms remained closed for several days until the storm dissipated, resulting in a loss of roughly per day, increasing global gasoline prices. A red alert was declared for Onslow in preparations for the landfall of Dominic. A crane worker was killed in Port Hedland while dismantling a crane.

In Onslow, the roof of the local library was blown off, resulting in flooding within the building. A nearby hospital also sustained flood damage. Several trees and power lines were downed by high winds and some roads were flooded.

Following the storm, the shires of Ashburton, Carnarvon, Upper Gascoyne, Murchison, Yalgoo, Moora, Northam, York, Quairading and Beverley were eligible for disaster assistance from the Australian Government.

Tropical Cyclone Ellie

Early on 30 January, the TCWC in Brisbane noted that a Tropical Low, had formed within a monsoon trough. Later that day the JTWC, reported that multi spectral imagery had shown a developing low level circulation center with deep convection located over the western quadrant of the Low level circulation centre. Late the next day the Bureau of Meteorology reported that the low had intensified into a tropical cyclone and assigned the name of Ellie to the cyclone. They also reported that Ellie had reached its peak winds of 80 km/h, (50 mph), which made Ellie a Category one cyclone on the Australian Tropical Cyclone Intensity Scale. Later that day the Joint Typhoon Warning Center initiated issuing warnings on Ellie designating it as Tropical Cyclone 12P and also reported peak wind speeds of 75 km/h, (45 mph) which made Ellie equivalent to a Tropical Storm on the Saffir–Simpson Hurricane Scale. Ellie made landfall near Mission Beach at about Midnight AEST, 2 February (1400 UTC), as a Category 1 system and weakened into a Tropical Low. TCWC Brisbane was expecting Tropical Low ex-Ellie to move back over the Coral Sea within 24 to 36 hours after Ellie made landfall and possibly reintensify into a tropical cyclone. However, this did not happen. The low that had been Ellie redeveloped within the south eastern Gulf of Carpentaria. Torrential rain from the remnants of Ellie flooded areas in Northern Queensland, causing about A$110 million (US$69.5 million) in damages. In Ingham, between Cairns and Townsville, some 50 homes were flooded, with 32 people evacuated to emergency accommodation at a local high school.

Tropical Cyclone Freddy