2019–20 Australian region cyclone season
The 2019–20 Australian region cyclone season is the period of the year when most tropical cyclones form in the southern Indian and Pacific Oceans between 90°E and 160°E. The season officially began on 1 November 2019 and will end on 30 April 2020; however, a tropical cyclone could form at any time between 1 July 2019 and 30 June 2020 and would count towards the season total. During the season, tropical cyclones will be officially monitored by the Australian Bureau of Meteorology (BOM), the Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG), and the National Weather Service of Papua New Guinea. The United States' Joint Typhoon Warning Center (JTWC), and other national agencies such as the Fiji Meteorological Service (FMS), the Meteorological Service of New Zealand (MetService), and Météo-France at La Réunion, will also monitor parts of the basin during the season.
|2019–20 Australian region cyclone season|
|First system formed||None formed|
|Last system dissipated||Season ongoing|
|Severe tropical cyclones||0|
|Average (1969-70 - 2018-19):||9-13||—|
|NIWA October (135°E—120°W)||9-12||4|
|Western South Pacific
|Eastern South Pacific
|Source: BOM's Season Outlooks for Tropical Cyclones|
Ahead of the cyclone season formally starting on November 1, the BoM, Fiji Meteorological Service (FMS), New Zealand's MetService and 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 2019. The outlook called for a near-average number of tropical cyclones for the 2019–20 season, with nine to twelve named tropical cyclones, predicted to occur between 135°E and 120°W, compared to an average of just over 10. At least four of the tropical cyclones were expected to intensify further and become severe tropical cyclones, while it was noted that a Category 5 severe tropical cyclone could occur during the season. In addition to contributing towards the Island Climate Update outlook, the BoM issued seven seasonal forecasts for various parts of the Australian region and South Pacific basin. For the entire Australian region between 90°E–160°E, the BoM predicted that the season would feature, a below-average amount of systems with only a 35% chance of more tropical cyclones. The BoM also thought that their self defined Western and Eastern regions, would both have a 57% chance of fewer tropical cyclones than normal developing. Their northern region and northwestern subregion would also see fewer tropical cyclones than normal, with only a 36% and 39% chance of more tropical cyclones than average. The BoM also issued two seasonal forecasts for their self-defined eastern and western regions of the South Pacific Ocean. They predicted that the Western region between 142.5°E and 165°E, had a 54% chance of seeing activity above its average of 4 tropical cyclones. The BoM also predicted that the Eastern Region between 165°E and 120°W, had a 41% chance of seeing activity above its average of 7 tropical cyclones.
The outlooks accounted for the effects of various major Australian climate drivers, namely the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). The BOM noted that sea surface temperature anomalies across the equatorial Pacific Ocean had been characteristic of a neutral ENSO phase since April. The international climate models utilised by the BOM also indicated that the neutral conditions would likely persist until at least February. A neutral ENSO phase typically has little influence on the Australian climate. Warmer than average sea surface temperatures in the central and western tropical Indian Ocean and cooler waters near Indonesia and northern Australia, indicating a positive IOD phase, had also persisted since May. The temperature difference increased throughout the year, and at the beginning of October, the BOM noted that the sea surface temperature anomaly of +1.76 °C was the highest observed value on record (since 2001). The anomaly continued to increase rapidly after this, with the value reaching +2.15 °C a fortnight later. The record-strength positive IOD contributed to the development of a region of higher than normal atmospheric pressure across northern Australia during September, after having remained near neutral throughout winter. The BOM noted that these factors also contributed to the tropical cyclone season outlook.
Bureau of Meteorology
The Australian Bureau of Meteorology monitors all tropical cyclones within the region, and assigns names to tropical cyclones that form outside of the areas of responsibility of TCWC Jakarta and TCWC Port Moresby. The next 14 names on the naming list are listed below:
The tropical cyclone warning centre in Jakarta monitors tropical cyclones from the Equator to 11°S and between the longitudes 90°E and 145°E. Should a tropical depression reach tropical cyclone strength within TCWC Jakarta's area of responsibility, it will be assigned the next name from the following list:
TCWC Port Moresby
Tropical cyclones that develop between the Equator and 11°S, between 151°E and 160°E, are assigned names by the tropical cyclone warning centre in Port Moresby, Papua New Guinea. Tropical cyclone formation in this area is rare, and no cyclones have been named in it since 2007. As names are assigned in a random order the whole list is shown below:
If a tropical cyclone enters the Australian region from the South Pacific basin (east of 160°E), it will retain the name assigned to it by the Fiji Meteorological Service (FMS) or MetService. Similarly, if a tropical cyclone enters the Australian region from the South-West Indian Ocean cyclone region (west of 90°E), it will retain the name assigned to it on behalf of Météo-France La Réunion by the Sub-Regional Tropical Cyclone Advisory Centres in Mauritius or Madagascar.
|Name||Dates||Peak intensity||Areas affected||Damages
- "Australian Tropical Cyclone Outlook for 2019 to 2020". Australian Bureau of Meteorology. 11 October 2019. Archived from the original on 14 October 2019. Retrieved 14 October 2019.
- Southwest Pacific Tropical Cyclone Outlook - October 2019 (Report). National Institute of Water and Atmospheric Research. October 11, 2019. Retrieved October 11, 2019.
- "South Pacific Tropical Cyclone Outlook for 2019 to 2020". Australian Bureau of Meteorology. October 11, 2019. Retrieved October 11, 2019.
- "ENSO Wrap-Up: Overview". Australian Bureau of Meteorology. 15 October 2019. Archived from the original on 15 October 2019. Retrieved 17 October 2019.
- "ENSO Wrap-Up: Indian Ocean". Australian Bureau of Meteorology. 1 October 2019. Archived from the original on 1 October 2019. Retrieved 14 October 2019.
- "ENSO Wrap-Up: Overview". Australian Bureau of Meteorology. 1 October 2019. Archived from the original on 1 October 2019. Retrieved 17 October 2019.
- "Tropical Cyclone Operational plan for the South Pacific & Southeast Indian Ocean, 2014 Edition" (PDF). WMO. Retrieved 2016-06-12.
- "Cyclone Names". Indonesian Agency for Meteorology, Climatology and Geophysics. Archived from the original on 17 June 2019. Retrieved 17 June 2019.
- Gary Padgett (2008). "Monthly Global Tropical Cyclone Summary October". Australian Severe Weather. Retrieved 2013-07-01.