1989–90 Australian region cyclone season

Seasonal summary

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PlotData= barset:Hurricane width:10 align:left fontsize:S shift:(4,-4) anchor:till from:14/07/1989 till:16/07/1989 color:C1 text:"02S (C1)" from:04/11/1989 till:13/11/1989 color:C2 text:"Pedro (C2)" from:13/12/1989 till:20/12/1989 color:C3 text:"Felicity (C3)" from:04/01/1990 till:17/01/1990 color:C1 text:"Rosita (C1)" from:11/01/1990 till:21/01/1990 color:C3 text:"Sam (C3)" from:24/01/1990 till:29/01/1990 color:C2 text:"Tina (C2)" from:26/01/1990 till:04/02/1990 color:C2 text:"Nancy (C2)" barset:break from:25/02/1990 till:06/03/1990 color:C3 text:"Vincent (C3)" from:28/02/1990 till:05/03/1990 color:C1 text:"Greg (C1)" from:04/03/1990 till:13/03/1990 color:C2 text:"Walter-Gregoara (C2)" from:04/03/1990 till:07/03/1990 color:C2 text:"Hilda (C2)" from:14/03/1990 till:26/03/1990 color:C5 text:"Alex (C5)" from:14/03/1990 till:26/03/1990 color:C4 text:"Ivor (C4)" from:11/04/1990 till:18/04/1990 color:C1 text:"Bessi (C1)"

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Systems

Tropical Storm 02S

| 1-min winds = 35 | 10-min winds = Tropical Storm 02S existed from 14 July to 16 July.

Tropical Cyclone Pedro

| 1-min winds = 65 | 10-min winds = 60 At 0:00 UTC on 6 November, the BOM detected an area of low pressure within a monsoonal trough near 7.8°S, 97.2°E., which gradually organized while drifting westward for the next couple of days. On 8 November, the disturbance strengthened into a tropical cyclone and was named Pedro. The cyclone continued to intensify before reaching its peak intensity at 13:00 UTC on November 10 with 10-minute sustained winds of around 70 mph and a minimum pressure of 982 mbar, with a short-lived eye visible on satellite imagery. As Pedro moved southward, strong vertical wind shear left the low-level center bare and displaced convection to the northwestern side of the storm. At 0:00 UTC on 13 November, Pedro's winds weakened below gale-force and the system degenerated into a remnant system, which dissipated the following day.

Pedro passed within 85 mi of Cocos Island, where a peak wind gust of around 85 mph was recorded. At least 7.9 in of precipitation fell on the island within a 24-hour period, causing localized flooding. A palm plantation and loading wharf were damaged by the storm.

Severe Tropical Cyclone Felicity

| 1-min winds = 70 | 10-min winds = 75

On 13 December, the BoM started to monitor a monsoon low, that had developed within the Arafura Sea to the northeast of Darwin. Over the next day, the system moved southeastwards over the Northern Territory, before it re-curved slightly and entered the Gulf of Carpentaria. Early on 15 December, the system was named Felicity by TCWC Brisbane, after it had become a category 1 tropical cyclone on the Australian Scale. During that day the JTWC initiated advisories on the system and designated it as Tropical Cyclone 07P, with peak 1-minute sustained wind speeds of 110 km/h. TCWC Brisbane subsequently reported peak 10-minute sustained wind speeds of 110 km/h, before the system made landfall over the Cape York Peninsula where it weakened below cyclone intensity. The system subsequently moved into the Coral Sea during 16 December, where it started to rapidly deepen, but did not reattain the classical characteristics of a tropical cyclone. As a result, both TCWC Nadi and TCWC Brisbane treated the system as a tropical depression over the next four days despite winds of between 110 and being observed in the southwest quadrant. Felicity subsequently dissipated during 20 December as it was absorbed by a short-wave trough of low pressure to the north of New Zealand. Some minor damage to vegetation was recorded on the Cape York Peninsula.

Tropical Cyclone Rosita

| 1-min winds = 50 | 10-min winds = 45 Rosita was first noted as a low-pressure system at 18:00 UTC on 4 January while it located well south of Java. Moving swiftly westward, the disturbance gradually organized for two days until slightly weakening due to increasing vertical wind shear. The system remained quasi-stationary until 9 January when a developing ridge in the middle-latitudes forced the disturbance northwestward. The low was ill-defined with a weak and sheared structure on satellite imagery while moving equatorward. By 6:00 UTC the following day, convection began to redevelop and consolidate through 12 January as the disturbance strengthened.

At 15:00 UTC on 13 January, tropical storm-force winds formed around the center, prompting the BOM to upgrade the low into Tropical Cyclone Rosita. The nascent cyclone tracked south-southeastward, remaining under the influence of vertical wind shear causing majority of convection to be displaced west of the center. Rosita once again changed course late the next day, shifting northwestward as it lost gale-force winds. The remnants tracked around the periphery of the more intense Severe Tropical Cyclone Sam, before moving equatorward and dissipating on 17 January.

Severe Tropical Cyclone Sam

| 1-min winds = 80 | 10-min winds = 70 Sam, 11 to 21 January 1990, near Western Australia

Tropical Cyclone Tina

| 1-min winds = 65 | 10-min winds = 50 Tina, 24 to 29 January 1990, crossed Western Australia

Tropical Cyclone Nancy

(Out of basin from 31 January to 1 February) | 1-min winds = 70 | 10-min winds = 60 In late January, a monsoon trough spawned a tropical depression on 26 January, over the Coral Sea. The depression developed good outflow, before gaining tropical cyclone characteristic on 31 January, and was designated as Tropical Cyclone Nancy. An upper-level trough forced the storm southward, before shifting southwestward. At 3:00 UTC on 1 February, Nancy reached its peak intensity with 10-minute sustained winds of around 60 mph and a minimum pressure of 975 mbar. Between 1 and 2 February, the cyclone gradually moved just offshore the Brisbane area. Nancy then weakened while continuing to move southward, before transitioning into an extratropical low on 4 February. The remnants eventually dissipated to the west of New Zealand on 8 February.

Nancy caused flash floods responsible for five fatalities.

Severe Tropical Cyclone Vincent

| 1-min winds = 70 | 10-min winds = 70 Vincent, 25 February to 6 March 1990, near Western Australia

Tropical Cyclone Greg

| 1-min winds = 30 | 10-min winds = 40 Greg, 28 February to 5 March 1990, Gulf of Carpentaria

Tropical Cyclone Walter–Gregoara

| 1-min winds = 55 | 10-min winds = 50 Walter existed from 3 to 27 March 1990.

Tropical Cyclone Hilda

| 1-min winds = 60 | 10-min winds = 60 Cyclone Hilda had cloud tops estimated at 19200 m tall. The measured cloud top temperature was -100 C which was the coldest cloud-top temperature ever measured. This record lasted until Typhoon Kammuri in 2019 with cloud tops of -109.35 C.

Severe Tropical Cyclone Alex

| 1-min winds = 130 | 10-min winds = 120 Alex Alex was a fairly intense system. It existed from 14 to 26 March 1990. Despite the intensity, Alex never caused significant damage.

Severe Tropical Cyclone Ivor

| 1-min winds = 75 | 10-min winds = 90 Ivor, 15 to 26 March 1990, crossed Cape York, Queensland

Tropical Cyclone Bessi

| 1-min winds = 40 | 10-min winds = 40 Bessi, 11 to 18 April 1990, Indian Ocean

Season effects

|- | Rosita || || bgcolor=#| || bgcolor=#|45 kn || bgcolor=#|988 hPa || None || || || |- | Tina || || bgcolor=#| || bgcolor=#|50 kn || bgcolor=#|976 hPa || Western Australia || || || |- | Nancy || || bgcolor=#| || bgcolor=#|60 kn || bgcolor=#|976 hPa || Queensland, New South Wales, New Zealand || || || |- | Greg || || bgcolor=#| || bgcolor=#|40 kn || bgcolor=#|990 hPa || None || || || |- | Walter – Gregoara || || bgcolor=#| || bgcolor=#|50 kn || bgcolor=#|985 hPa || None || || || |- | Hilda || || bgcolor=#| || bgcolor=#|60 kn || bgcolor=#|970 hPa || New Caledonia || || || |- | Bessi || || bgcolor=#| || bgcolor=#|45 kn || bgcolor=#|990 hPa || None || || || |}

Notes

References

References

1. "Tropical Cyclone Pedro".
2. "Tropical Cyclone Felicity". Australian Bureau of Meteorology.
3. "Annual Tropical Cyclone Report: 1990". United States Navy, United States Air Force.
4. Singh, Arveen K. (Summer 1990). "Tropical depression in Coral Sea (former T.C. Felicity), December 18–20, 1989". United States National Oceanic and Atmospheric Administration's National Oceanographic Data Service.
5. "Tropical Cyclone Rosita".
6. "Tropical Cyclone Nancy". Bureau of Meteorology.
7. "EMA Disasters Database".
8. Jiang, Haiyan. (2014-06-01). "Contribution of Tropical Cyclones to Global Very Deep Convection". Journal of Climate.
9. Ebert, Elizabeth E.. (1992-10-01). "Observations of Record Cold Cloud-Top Temperatures in Tropical Cyclone Hilda (1990)". Monthly Weather Review.
10. Bachmeier, Scott. (30 November 2019). "Typhoon Kammuri in the West Pacific Ocean, with record cold cloud-top temperatures". Cooperative Institute for Meteorological Satellite Studies.
11. ["1990 Tropical Cyclone Rosita (1990005S13112)"]({{IBTRACS url). International Best Track Archive for Climate Stewardship.
12. Ready, Steve. (2 June 1992). "The South Pacific and Southeast Indian Ocean tropical cyclone season 1989–90". Australian Meteorological Magazine.
13. ["1990 Severe Tropical Cyclone Nancy (1990027S18156)"]({{IBTRACS url). International Best Track Archive for Climate Stewardship.
14. "Tropical Cyclone Greg". Australian Bureau of Meteorology.
15. ["1990 Tropical Cyclone Greg (1990059S13135)"]({{IBTRACS url). International Best Track Archive for Climate Stewardship.
16. ["1990 Intense Tropical Cyclone Gregoara:Walter (1990062S13091)"]({{IBTRACS url). International Best Track Archive for Climate Stewardship.
17. ["1990 Tropical Cyclone Hilda (1990060S15170)"]({{IBTRACS url). International Best Track Archive for Climate Stewardship.
18. "Tropical Cyclone Bessi". Australian Bureau of Meteorology.