2019–20 Australian region cyclone season

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
2019–20 Australian region cyclone season
2019-2020 Australian region cyclone season summary.png
Season summary map
Seasonal boundaries
First system formed4 January 2020
Last system dissipatedSeason ongoing
Strongest storm
NameClaudia
 • Maximum winds150 km/h (90 mph)
(10-minute sustained)
 • Lowest pressure969 hPa (mbar)
Seasonal statistics
Tropical lows2
Tropical cyclones2
Severe tropical cyclones1
Total fatalities0
Total damageNone
Related articles
Australian region tropical cyclone seasons
2017–18, 2018–19, 2019–20, 2020–21, 2021–22

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.

Seasonal forecasts[edit]

Source/Record Tropical
Cyclone
Severe
Tropical Cyclone
Ref
Record high: 21 12
Record low: 3 0
Average (1969-70 - 2018-19): 9-13  — [1]
NIWA October (135°E—120°W) 9-12 4 [2]
Region Average
number
Chance
of more
Chance
of less
Actual
activity
Overall
(90°E–160°E)
11 35% 65% 2
Western region
(90°E–125°E)
7 43% 57% 2
Northwestern sub-region
(105°E–130°E)
5 39% 61% 2
Northern region
(125°E–142.5°E)
3 36% 64% 1
Eastern region
(142.5°E–160°E)
4 43% 57% 0
Western South Pacific
(142.5°E—165°E)
4 54% 46% 0
Eastern South Pacific
(165°E—120°W)
7 41% 59% 0
Source: BOM's Season Outlooks for Tropical Cyclones[1][3]

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.[2] 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.[2] 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.[2] 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.[1][3] 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.[1] 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.[1] 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.[1] The BoM also issued two seasonal forecasts for their self-defined eastern and western regions of the South Pacific Ocean.[3] 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.[3]

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.[1] A neutral ENSO phase typically has little influence on the Australian climate.[4] 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.[5] 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).[6] The anomaly continued to increase rapidly after this, with the value reaching +2.15 °C a fortnight later.[4] 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.[1]

Season summary[edit]

Tropical cyclone scales#Comparisons across basins

Systems[edit]

Tropical Cyclone Blake[edit]

Category 1 tropical cyclone (Australian scale)
Tropical storm (SSHWS)
Blake 2020-01-06 0537Z.jpg Blake 2020 track.png
Duration4 January – 11 January
Peak intensity75 km/h (45 mph) (10-min)  986 hPa (mbar)

During 4 January, the BoM reported that Tropical Low 02U had started to develop within the monsoon trough, about 750 km (465 mi).[7] Citing considerable rotation extending into the mid troposphere, well-established dual-channel outflow and warm sea surface temperatures, the JTWC assessed the system as having a moderate chance of attaining tropical cyclone intensity within the following 24 hours.[8] The system gradually gathered strength in the favourable environment as it tracked slowly towards the south-southwest,[9] leading the JTWC to issue a tropical cyclone formation alert at 03:30 UTC the following day.[10] The BOM indicated that sustained gale-force winds had developed on the western side of the tropical low at 15:00 UTC,[11] and the system was designated as Tropical Cyclone 06S by the JTWC a few hours later.[12] Gales fully encircled the system by 00:00 UTC on 6 January, prompting the BOM to upgrade the low to a Category 1 tropical cyclone on the Australian scale, the first of the season. The system was given the official name Blake by the BOM.[13] Blake began to intensify steadily after being upgraded into a tropical cyclone, attaining 10-minute sustained winds of 75 km/h (45 mph) and one-minute sustained winds of 95 km/h (60 mph) within a few hours.[14][15] Soon afterwards, however, the system's development stalled due to land interaction with the nearby coastline of Western Australia.[15] The cyclone made landfall on Dampier Peninsula just before 09:00 UTC, approximately 85 km (55 mi) north of Broome.[16] Blake turned to the southwest and re-emerged over the Indian Ocean at 15:00 UTC; however, the system's structure had deteriorated significantly while the centre was over land.[17][18] As the weakened cyclone continued over water towards the southwest, paralleling the coastline, low vertical wind shear allowed an area of deep convection to gradually redevelop over the system on 7 January.[19] Blake made its final landfall just to the west of the Wallal Downs cattle station on Eighty Mile Beach at approximately 17:00 UTC at minimal Category 1 intensity. Within an hour of crossing the coast, the system weakened to a tropical low.[20] The JTWC discontinued advisories at 00:00 UTC on 8 January as the system moved farther inland;[21] however, the system maintained tropical storm intensity until 12 hours later.

Severe Tropical Cyclone Claudia[edit]

Category 3 severe tropical cyclone (Australian scale)
Category 1 tropical cyclone (SSHWS)
Claudia 2020-01-13 0530Z.jpg Claudia 2020 track.png
Duration4 January – 17 January
Peak intensity150 km/h (90 mph) (10-min)  969 hPa (mbar)

On 4 January, the BOM noted the formation of a weak tropical low over Indonesia's Maluku Islands.[22] In the ensuing days, the tropical low tracked slowly southeastwards across the Arafura Sea, towards the Gulf of Carpentaria. Significant development was hampered by strong vertical wind shear; however, very warm sea surface temperatures of up to 32 °C (90 °F) allowed the low to gradually increase in organisation.[23] On 7 January, shortly after the low passed near Cape Wessel in the Northern Territory, the BOM published their first forecast track map for the system, and issued a tropical cyclone watch for the northern coastline of Arnhem Land.[24] On the next day, the JTWC issued a Tropical Cyclone Formation Alert on the system as it began to organize just northwest of the Gove Peninsula.[25] As the system remained disorganized, the JTWC cancelled the first tropical cyclone formation alert, but later issued another one on January 10 as it re-organized itself, following land interaction with the Top End.[citation needed]. It was later upgraded to a tropical cyclone by the BOM as it was northeast of Kalumburu, receiving the name Claudia on January 11.[26] On the next day, the system was upgraded to a category 2 tropical cyclone. Several hours later, following a decrease in wind shear, Claudia's structure quickly improved, with the storm acquiring hurricane-force winds. It was then upgraded by the BOM to a severe tropical cyclone, during this intensification spell.[27].

The storm continued intensifying, indicated by a improvement of the storm’s structure over the proceeding hours. The storm eventually reached its peak intensity with 1-minute sustained winds of 90 mph (150 km/h) and 969 millibars with a small, ragged eye forming on microwave imagery on January 13. Despite this, a decrease in sea surface temperatures as it quickly accelerated eastwards caused the storm to rapidly weaken throughout January 14, indicated by a loss of deep convection near the storm’s center. The next evening on January 15, the BOM issued their last advisory on Claudia as it began to weaken.[28] Claudia dissipated as a tropical low on 17 January.[29]

When the system was still a tropical low on 10 January, portions of the Top End received unusually large amounts of rainfall due to the system's slow movement. Darwin received 45 mm (1.7 inches) of rain, Noonamah received 56 mm (2.2 inches of rain, Pirlangimpi received 80.8 mm (3.1 inches) of rain, Charles Point received 151 mm (5.9 inches) of rain, and Dum In Mirrie Island received a staggering 410 mm (16.1 inches) of rain as a result of the system.[30]

Storm names[edit]

Bureau of Meteorology[edit]

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:

  • Blake
  • Claudia
  • Damien (unused)
  • Esther (unused)
  • Ferdinand (unused)
  • Gretel (unused)
  • Harold (unused)
  • Imogen (unused)
  • Joshua (unused)
  • Kimi (unused)
  • Lucas (unused)
  • Marian (unused)
  • Niran (unused)
  • Odette (unused)

TCWC Jakarta[edit]

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. If 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:[31][32]

  • Mangga (unused)
  • Seroja (unused)
  • Teratai (unused)
  • Anggrek (unused)
  • Bakung (unused)
  • Cempaka (unused)
  • Dahlia (unused)
  • Flamboyan (unused)

TCWC Port Moresby[edit]

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.[33] As names are assigned in a random order the whole list is shown below:

  • Alu (unused)
  • Buri (unused)
  • Dodo (unused)
  • Emau (unused)
  • Fere (unused)
  • Hibu (unused)
  • Ila (unused)
  • Kama (unused)
  • Lobu (unused)
  • Maila (unused)

Others[edit]

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.

Season effects[edit]

2019–20 Australian region cyclone season
Name Dates Peak intensity Areas affected Damage
(US$)
Deaths
Category Wind speed
(km/h (mph))
Pressure
(hPa)
Blake 4–11 Jan. Category 1 tropical cyclone 75 (45) 986 Western Australia None 0
Claudia 4–17 Jan. Category 3 severe tropical cyclone 150 (90) 969 Eastern Indonesia, Top End, Kimberley None 0
Season aggregates
2 systems 4 Jan.–Present 140 (85) 969 None 0

See also[edit]

References[edit]

  1. ^ a b c d e f g h "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.
  2. ^ a b c d Southwest Pacific Tropical Cyclone Outlook - October 2019 (Report). National Institute of Water and Atmospheric Research. October 11, 2019. Retrieved October 11, 2019.
  3. ^ a b c d "South Pacific Tropical Cyclone Outlook for 2019 to 2020". Australian Bureau of Meteorology. October 11, 2019. Retrieved October 11, 2019.
  4. ^ a b "ENSO Wrap-Up: Overview". Australian Bureau of Meteorology. 15 October 2019. Archived from the original on 15 October 2019. Retrieved 17 October 2019.
  5. ^ "ENSO Wrap-Up: Indian Ocean". Australian Bureau of Meteorology. 1 October 2019. Archived from the original on 1 October 2019. Retrieved 14 October 2019.
  6. ^ "ENSO Wrap-Up: Overview". Australian Bureau of Meteorology. 1 October 2019. Archived from the original on 1 October 2019. Retrieved 17 October 2019.
  7. ^ "Western Region Tropical Cyclone Outlook". Australian Bureau of Meteorology. 4 January 2020. Archived from the original on 4 January 2020. Retrieved 4 January 2020.
  8. ^ "Significant Tropical Weather Advisory for the Indian Ocean (91S)". Joint Typhoon Warning Center. Naval Meteorology and Oceanography Command. 4 January 2020. Archived from the original on 4 January 2020. Retrieved 4 January 2020.
  9. ^ "Tropical Low 02U Forecast Track Map #4 (00Z)". Australian Bureau of Meteorology. 5 January 2020. Archived from the original on 5 January 2020. Retrieved 5 January 2020.
  10. ^ "Tropical Cyclone Formation Alert (06S)". United States Joint Typhoon Warning Center. 5 January 2020. Archived from the original on 5 January 2020. Retrieved 5 January 2020.
  11. ^ "Tropical Low 02U Forecast Track Map #8 (15Z)". Australian Bureau of Meteorology. 5 January 2020. Archived from the original on 5 January 2020. Retrieved 5 January 2020.
  12. ^ "Tropical Cyclone 06S Warning #1 (18Z)". United States Joint Typhoon Warning Center. 5 January 2020. Archived from the original on 5 January 2020. Retrieved 5 January 2020.
  13. ^ "Tropical Cyclone Blake Forecast Track Map #11 (00Z)". Australian Bureau of Meteorology. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  14. ^ "Tropical Cyclone Blake Forecast Track Map #13 (06Z)". Australian Bureau of Meteorology. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  15. ^ a b "Tropical Cyclone 06S Warning #3 (06Z)". Joint Typhoon Warning Center. Naval Meteorology and Oceanography Command. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  16. ^ "Tropical Cyclone Blake Forecast Track Map #14 (09Z)". Australian Bureau of Meteorology. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  17. ^ "Tropical Cyclone Blake Forecast Track Map #16 (15Z)". Australian Bureau of Meteorology. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  18. ^ "Tropical Cyclone Blake Technical Bulletin #3 (18Z)". Australian Bureau of Meteorology. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  19. ^ "Tropical Cyclone Blake Technical Bulletin #4 (00Z)". Australian Bureau of Meteorology. 7 January 2020. Archived from the original on 7 January 2020. Retrieved 7 January 2020.
  20. ^ "Tropical Cyclone Blake Forecast Track Map #25 (18Z)". Australian Bureau of Meteorology. 7 January 2020. Archived from the original on 7 January 2020. Retrieved 7 January 2020.
  21. ^ "Tropical Cyclone 06S Warning #10 (00Z)". United States Joint Typhoon Warning Center. 8 January 2020. Archived from the original on 8 January 2020. Retrieved 8 January 2020.
  22. ^ "Northern Region Tropical Cyclone Outlook". Australian Bureau of Meteorology. 4 January 2020. Archived from the original on 4 January 2020. Retrieved 4 January 2020.
  23. ^ "Significant Tropical Weather Advisory for the Pacific Ocean (06Z)". Joint Typhoon Warning Center. Naval Meteorology and Oceanography Command. 6 January 2020. Archived from the original on 6 January 2020. Retrieved 6 January 2020.
  24. ^ "Tropical Low 03U Forecast Track Map #1 (00Z)". Australian Bureau of Meteorology. 7 January 2020. Archived from the original on 7 January 2020. Retrieved 7 January 2020.
  25. ^ "Tropical Cyclone Formation Alert (07S)". United States Joint Typhoon Warning Center. 8 January 2020. Archived from the original on 8 January 2020. Retrieved 8 January 2020.
  26. ^ "Tropical Cyclone Advice Number 31". Bureau of Meteorology. January 11, 2020. Archived from the original on January 11, 2020. Retrieved January 11, 2020.
  27. ^ "Severe Tropical Cyclone Claudia Forecast Track Map". Bureau of Meteorology. January 12, 2020. Archived from the original on January 12, 2020. Retrieved January 12, 2020.
  28. ^ "Ex-TC Claudia Forecast Track". Australian Bureau of Meteorology. Retrieved January 15, 2020. |archive-url= is malformed: save command (help)
  29. ^ "Western Area High Seas Forecast". Australian Bureau of Meteorology. 17 January 2020. Archived from the original on 18 January 2020. Retrieved 18 January 2020.
  30. ^ Aisthorpe, Judith; Perera, Alicia (January 10, 2020). "Darwin cops a drenching as the Big Wet arrives ... and there may still be more to come". Northern Territory News. Retrieved January 11, 2020.
  31. ^ "Tropical Cyclone Operational plan for the South Pacific & Southeast Indian Ocean, 2014 Edition" (PDF). WMO. Retrieved 2016-06-12.
  32. ^ "Cyclone Names". Indonesian Agency for Meteorology, Climatology and Geophysics. Archived from the original on 17 June 2019. Retrieved 17 June 2019.
  33. ^ Gary Padgett (2008). "Monthly Global Tropical Cyclone Summary October". Australian Severe Weather. Retrieved 2013-07-01.

External links[edit]