ROSITA
1989-90 season · AU198990_03U
History
Tropical Cyclone Rosita was a weak, short-lived system that spent its entire life over the open waters of the eastern Indian Ocean during January 1990.
The Bureau of Meteorology first identified the precursor low at 18:00 UTC on 4 January, well to the south of Java near 12.7°S, 111.7°E. Moving briskly westward, the disturbance slowly became better organised over the following two days before vertical wind shear increased and caused it to lose definition. The low then remained almost stationary until 9 January, when a strengthening mid-latitude ridge to its south steered it towards the northwest. For several days the system appeared ragged and sheared on satellite imagery, but as it drifted towards the equator the shear temporarily relaxed and convection redeveloped and consolidated around the centre between 10 and 12 January.
Gale-force winds were assessed around the circulation at 15:00 UTC on 13 January, and the Perth Tropical Cyclone Warning Centre named the system Rosita. This marked its peak as a Category 1 cyclone on the Australian scale, with a minimum central pressure of about 988 hPa, maximum 10-minute sustained winds near 85 km/h and gusts to around 110 km/h. Rosita tracked south-southeastward while named, though shear kept the bulk of its deep convection displaced well to the west of the low-level centre. Late on 14 January it turned back towards the northwest and came under the influence of the much larger and stronger Severe Tropical Cyclone Sam to its south. Gale-force winds were lost on 15 January, and the remnant low-level swirl drifted equatorward around Sam's periphery before dissipating on 17 January.
Rosita never approached land, staying more than 1,000 km off the North West Shelf of Western Australia, and no casualties, injuries or structural damage were reported. Its only operational impact was the issuing of high-seas gale warnings for shipping in the eastern Indian Ocean. The name was reused in April 2000 for a far more destructive Category 5 cyclone that crossed the coast south of Broome.
Sources: Bureau of Meteorology report Wikipedia
View full track data (52 observations)
| Date/Time (UTC) | Category | Position | Pressure | Wind |
|---|---|---|---|---|
| 1990-01-04 18:00:00 | 1 | -12.7, 111.7 | 1004 hPa | 13 km/h |
| 1990-01-05 00:00:00 | 1 | -12.8, 110.6 | 1004 hPa | 13 km/h |
| 1990-01-05 06:00:00 | 1 | -12.9, 109.8 | 1002 hPa | 13 km/h |
| 1990-01-05 12:00:00 | 1 | -13.0, 108.5 | 1001 hPa | 13 km/h |
| 1990-01-05 18:00:00 | 1 | -13.2, 107.0 | 1001 hPa | 13 km/h |
| 1990-01-06 00:00:00 | 1 | -13.4, 105.7 | 1000 hPa | 15 km/h |
| 1990-01-06 06:00:00 | 1 | -13.8, 104.4 | 998 hPa | 15 km/h |
| 1990-01-06 12:00:00 | 1 | -14.0, 104.2 | 1000 hPa | 15 km/h |
| 1990-01-06 18:00:00 | 1 | -14.3, 103.8 | 1000 hPa | 15 km/h |
| 1990-01-07 00:00:00 | 1 | -14.6, 103.6 | 1000 hPa | 13 km/h |
| 1990-01-07 06:00:00 | 1 | -15.0, 103.4 | 1000 hPa | 13 km/h |
| 1990-01-07 12:00:00 | 1 | -15.2, 103.6 | 1001 hPa | 13 km/h |
| 1990-01-07 18:00:00 | 1 | -15.2, 103.8 | 1001 hPa | 13 km/h |
| 1990-01-08 00:00:00 | 1 | -15.1, 104.2 | 1002 hPa | 13 km/h |
| 1990-01-08 06:00:00 | 1 | -14.9, 104.3 | 1002 hPa | 13 km/h |
| 1990-01-08 12:00:00 | 1 | -14.4, 104.3 | 1002 hPa | 13 km/h |
| 1990-01-08 18:00:00 | 1 | -14.0, 104.2 | 1002 hPa | 13 km/h |
| 1990-01-09 00:00:00 | 1 | -13.5, 104.1 | 1003 hPa | 13 km/h |
| 1990-01-09 06:00:00 | 1 | -13.2, 103.8 | 1004 hPa | 13 km/h |
| 1990-01-09 12:00:00 | 1 | -12.3, 103.2 | 1004 hPa | 13 km/h |
| 1990-01-09 18:00:00 | 1 | -11.6, 102.6 | 1003 hPa | 13 km/h |
| 1990-01-10 00:00:00 | 1 | -10.8, 102.0 | 1002 hPa | 13 km/h |
| 1990-01-10 06:00:00 | 1 | -10.0, 101.3 | 1000 hPa | 13 km/h |
| 1990-01-10 12:00:00 | 1 | -9.8, 100.4 | 1000 hPa | 13 km/h |
| 1990-01-10 18:00:00 | 1 | -10.0, 100.2 | 1000 hPa | 13 km/h |
| 1990-01-11 00:00:00 | 1 | -10.3, 100.1 | 1000 hPa | 13 km/h |
| 1990-01-11 06:00:00 | 1 | -10.5, 100.1 | 1000 hPa | 13 km/h |
| 1990-01-11 12:00:00 | 1 | -10.8, 100.1 | 1000 hPa | 13 km/h |
| 1990-01-11 18:00:00 | 1 | -11.0, 100.3 | 1000 hPa | 13 km/h |
| 1990-01-12 00:00:00 | 1 | -11.1, 100.6 | 1000 hPa | 13 km/h |
| 1990-01-12 06:00:00 | 1 | -11.3, 101.1 | 998 hPa | 15 km/h |
| 1990-01-12 12:00:00 | 1 | -11.8, 101.4 | 998 hPa | 15 km/h |
| 1990-01-12 18:00:00 | 1 | -12.3, 101.7 | 997 hPa | 18 km/h |
| 1990-01-13 00:00:00 | 1 | -12.9, 101.9 | 995 hPa | 21 km/h |
| 1990-01-13 06:00:00 | 1 | -13.4, 102.1 | 992 hPa | 21 km/h |
| 1990-01-13 12:00:00 | 1 | -13.9, 102.2 | 990 hPa | 23 km/h |
| 1990-01-13 18:00:00 | 1 | -14.4, 102.3 | 988 hPa | 23 km/h |
| 1990-01-14 00:00:00 | 1 | -14.9, 102.5 | 988 hPa | 23 km/h |
| 1990-01-14 06:00:00 | 1 | -15.4, 102.6 | 990 hPa | 21 km/h |
| 1990-01-14 12:00:00 | 1 | -15.8, 102.6 | 990 hPa | 21 km/h |
| 1990-01-14 18:00:00 | 1 | -16.4, 102.6 | 994 hPa | 21 km/h |
| 1990-01-15 00:00:00 | 1 | -16.6, 102.1 | 996 hPa | 18 km/h |
| 1990-01-15 06:00:00 | 1 | -16.3, 101.6 | 997 hPa | 15 km/h |
| 1990-01-15 12:00:00 | 1 | -16.0, 101.1 | 998 hPa | 15 km/h |
| 1990-01-15 18:00:00 | 1 | -15.6, 100.5 | 999 hPa | 15 km/h |
| 1990-01-16 00:00:00 | 1 | -15.2, 100.0 | 1000 hPa | 13 km/h |
| 1990-01-16 06:00:00 | 1 | -14.4, 99.6 | 1000 hPa | 13 km/h |
| 1990-01-16 12:00:00 | 1 | -13.8, 99.2 | 1000 hPa | 13 km/h |
| 1990-01-16 18:00:00 | 1 | -13.2, 98.8 | 1000 hPa | 13 km/h |
| 1990-01-17 00:00:00 | 1 | -12.6, 98.6 | 1000 hPa | 13 km/h |
| 1990-01-17 06:00:00 | 1 | -12.0, 98.3 | 1001 hPa | 13 km/h |
| 1990-01-17 12:00:00 | 1 | -11.2, 98.1 | 1002 hPa | 13 km/h |