The 2014–15 Australian region cyclone season was a slightly below average tropical cyclone season, though it featured numerous intense cyclones. The season officially ran from 1 November 2014, to 30 April 2015, however, a tropical cyclone formed at any time between 1 July 2014, and 30 June 2015 would count towards the season total. During the season, tropical cyclones were officially monitored, by one of the five Tropical Cyclone Warning Centres (TCWCs) that are operated in this region.
Three of the five centres are operated by the Australian Bureau of Meteorology (BoM) in Perth, Darwin, and Brisbane, while the other two are operated by the National Weather Service of Papua New Guinea in Port Moresby and the Indonesian Agency for Meteorology, Climatology and Geophysics in Jakarta, Indonesia. The United States Joint Typhoon Warning Center (JTWC) and other national meteorological services, including Météo-France, also monitored the basin during the season.
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Seasonal forecasts Region Chance ofmore Averagenumber Actualactivity Whole34%118 Western 43%73 North-Western 38%50 Northern 46%32 Eastern 42%43 Southern Pacific48%159 Western South Pacific56%87 Eastern South Pacific47%112 Source: BOM's Seasonal Outlooks for Tropical Cyclones.
Ahead of the cyclone season, the Australian Bureau of Meteorology (BoM), the New Zealand National Institute of Water and Atmospheric Research (NIWA) and various other Pacific Meteorological services, all contributed towards the Island Climate Update tropical cyclone outlook that was released during October 2014. The outlook took into account the ENSO neutral conditions that had been observed across the Pacific and analogue seasons that had ENSO neutral and weak El Niño conditions occurring during the season. The outlook called for a near average number of tropical cyclones for the 2014–15 season, with eight to twelve named tropical cyclones, to occur between 135°E and 120°W compared to an average of 10. At least four of the tropical cyclones were expected to become category 3 severe tropical cyclones, while three could become category 4 severe tropical cyclones, they also noted that a Category 5 severe tropical cyclone was unlikely to occur.
In addition to contributing towards the Island Climate Update outlook, the BoM issued eight seasonal forecasts during October 2014, for the Australian region and the Southern Pacific with each forecast covering the whole tropical cyclone year. Each forecast issued took into account the near El Niño conditions that had developed over the region and the El Niño episode that was expected to develop during the season. For the basin as a whole, they predicted that there was a 34% chance, that the season would be near its average of around 11 tropical cyclones. For the Western region between 90°E and 125°E, the BoM forecast that the area would see activity near to the average of 7, with a 43% chance of an above-average cyclone season. TCWC Perth also noted that there was a likelihood of two tropical cyclones and a significant likelihood of at least one severe tropical cyclone impacting Western Australia.
For the North-Western subregion between 105°E and 130°E, it was predicted that activity would be below average, with a 38% chance of above average tropical cyclone activity. The Northern Territory which was defined as being between as being 125°E and 142.5°E had a 46% chance of an above average season, with TCWC Darwin noting that all of the climate drivers were pointing towards a typical tropical cyclone season for Northern Australia. The Eastern region between 142.5°E and 160°E was predicted to have a near normal tropical cyclone season, though it was noted that there was a possibility of a delayed start to the season. The BoM also issued 3 seasonal forecasts for the Southern Pacific between 142.5°E and 120°W, one for the Western Southern Pacific region between 142.5°E and 165°E and one for the Eastern Southern Pacific region between 165°E and 120°W. They predicted that the region as a whole would experience near average tropical cyclone activity during the coming season with a 55% chance of it being above average. The Western region was predicted to have 39% chance of being above average while the Eastern region had a 55% chance of being above average.
An updated Island Climate Update tropical cyclone outlook was issued during February 2015, which suggested that near normal activity was still possible. The outlook took into account Tropical Cyclones Niko and Ola as well as the weak El Niño conditions, that were predicted to persist over the region. As a result, the update predicted that an additional six to eight named tropical cyclones would develop over the basin, which would bring the overall total to between eight and ten tropical cyclones. The update also predicted that at least four tropical cyclones would intensify into category three severe tropical cyclones, of which three could intensify and become either a category four or five severe tropical cyclones.
Seasonal summary
Systems Tropical Low 01U
On 3 December, TCWC Perth reported that Tropical Low 01U had developed over open water to the southwest of Cocos (Keeling) Islands, after various applications of the Dvorak technique had produced results between T2.0 and T3.0. They also reported that the low could develop into a tropical cyclone during the following six to twelve hours, however, TCWC Perth issued its final advisory on the system during the next day as the system was not likely to develop into a tropical cyclone and had started weakening.
Tropical Cyclone Bakung
During 10 December, a tropical low developed about to the north-east of the Cocos (Keeling) Islands. The system had developed within a favourable environment for further development, with low to moderate vertical wind shear and a good poleward outflow which was being enhanced by a trough of low pressure. Over the next day, the system gradually intensified/developed further, with atmospheric convection deepening near the centre of the system. TCWC Jakarta subsequently named the low Bakung during 11 December, as it was thought that the system had become a Category 2 tropical cyclone on the Australian Scale. At the same time, TCWC Jakarta reported that Bakung had peaked with 10-minute sustained windspeeds of before the JTWC initiated advisories on the system later that day and designated it Tropical Cyclone 03S.
On 12 December, TCWC Jakarta reported that the system had weakened into a Category 1 tropical cyclone, while the JTWC reported that the system had intensified slightly and reached its peak intensity with 1-minute sustained windspeeds of . Early the next day as Tropical Cyclone Bakung continued to move westwards, it moved out of the Australian region and into the South-West Indian Ocean. However, during that day the system's low-level circulation centre became exposed and displaced about from the deep convection. As a result, TCWC Jakarta and the JTWC issued their final warnings on the system, while RSMC La Réunion declared it to be a remnant low in their only warning on the system.
Severe Tropical Cyclone Kate
On 21 December, TCWC Perth reported that Tropical Low 04U had developed within the monsoon trough to the southeast of Sumatra, Indonesia. Over the next few days, the system gradually developed further as it moved south-eastwards before it started to move towards the southwest, passing on the Cocos (Keeling) Islands during 23 December. Early the next day, it intensified into a Category 1 tropical cyclone, as BOM named the system Kate. The next day, Kate continued to intensify as an eye developed and reached peak intensity as a Category 4 severe tropical cyclone. On 27 December, it weakened as it underwent an eyewall replacement cycle. On 30 December, the BoM reported that Kate had moved out of the Australian region and into the South-West Indian Ocean basin with 10-minute sustained winds of .
107.6mm of rain was recorded in a 24-hour period on the island. Flooding was reported from Home and West Islands. Some trees were damaged and there was some property damage.
Tropical Low 05U
On 2 January, TCWC Perth and Darwin started to monitor Tropical Low 05U, that had developed within the monsoon trough near Wyndham in the Kimberley region of Western Australia. Over the next few days, the low moved slowly towards the southwest and passed to the southeast of Derby during 6 and 7 January. On 8 January, the low began a southward track before tracking to the east on 9 January. During the same day, the low moved south of Fitzroy Crossing and south of Halls Creek later in the evening. The system crossed into the Northern Territory early on 10 January before dissipating later that day.
In total, over 1000mm of rain was recorded over inland communities due to 05U.
Tropical Low 06U
On 10 January, TCWC Brisbane reported that Tropical Low 06U had developed within the monsoon trough, within an unfavorable environment for further development to the northeast of Queensland. Over the next couple of days, the system moved southeastwards and may have influenced the track of Tropical Low 07U, before it was last noted during 13 January.
Tropical Low 07U
On 10 January, the BoM started to monitor a tropical low south of the Solomon Islands. It gradually moved on the south, passing just east of Australia, before it was last noted on the 13th of the same month as it dissipated to the northwest of New Caledonia.
It peaked at 55 km/h (35 mph) on its lifetime, with 998 hPa (mbar).
Tropical Low 08U
During 17 January, a tropical low that had been monitored by the BoM for a few days, moved into the Northern Kimberley region from the Northern Territory. Over the next couple of days, the system moved south-westwards over land before it moved offshore and into the Indian Ocean near Broome during 19 January. As computer models were predicting conditions surrounding the low to be marginally favourable for further development, TCWC Perth expected the system to develop into a tropical cyclone and issued tropical cyclone advice for coastal areas from Kuri Bay to Exmouth. However, as the system spent more time over land than had been forecasted and vertical wind shear did not weaken as much as forecasted. As a result, the system failed to develop into a tropical cyclone as it moved south-westwards towards the Pilbara coast before it dissipated near Port Hedland during 20 January.
Tropical Low 09U
Tropical Low 12U
On 13 February, a tropical low developed roughly 700 km (430 mi) southwest of the Cocos (Keeling) Islands. The BoM stopped warning on it late on 16 February as it moved in a southerly direction.
Severe Tropical Cyclone Lam
Cyclone Lam was the strongest storm to strike Australia's Northern Territory since Cyclone Monica in 2006. It formed from the monsoon trough on 12 February in the Coral Sea. For much of its duration, the system moved westward due to a ridge to the south. The system crossed over the Cape York Peninsula and moved into the Gulf of Carpentaria, whereupon it gradually organized due to warm waters and favorable outflow. On 16 February, the Bureau of Meteorology (BoM) classified it as a Category 1 on the Australian tropical cyclone intensity scale and gave it the name Lam. The storm intensified further while drifting toward the Wessel Islands, developing an eye and strengthening to the equivalence of a minimal hurricane on 18 February. It strengthened to reach maximum sustained winds of early on 19 February before turning to the southwest, making it a Category 4 cyclone. That day, it made landfall on Northern Territory between Milingimbi and Elcho Island at peak intensity, and it rapidly weakened over land. About six hours after Lam moved ashore, Cyclone Marcia struck Queensland as a Category 5 cyclone, marking the first time on record that two storms of Category 4 intensity struck Australia on the same day.