GWENDA
1998-99 season · AU199899_13U
History
Severe Tropical Cyclone Gwenda developed from a tropical disturbance over the Arafura Sea in early April 1999, being classified as a tropical low on 2 April before being named as a Category 1 cyclone on 4 April. What followed was one of the most dramatic intensification sequences on record: over approximately 30 hours, the storm's 10-minute sustained winds surged from 75 to 225 km/h while central pressure plummeted by 90 hPa to reach 900 hPa, placing Gwenda among the most intense cyclones ever recorded in the Australian region and making it the world's strongest storm of 1999. The Bureau of Meteorology rated it Category 5 at its peak.
Gwenda's ferocity proved short-lived. Increasing wind shear and a rapid acceleration in forward speed caused swift deterioration, and the cyclone came ashore late on 7 April as a Category 2 system, striking the Pilbara coast of Western Australia approximately 45 km east of Port Hedland. Damage was far less severe than authorities had feared. Port Hedland experienced winds around 100 km/h and minor structural damage, with police reporting only one house badly affected and no fatalities or injuries. Rainfall was the most significant impact, with Carlindi recording a peak of 205 mm and localised flooding occurring in several towns including Nullagine. Five campers were stranded in the outback when floodwaters swept away their vehicle, though all survived. Gwenda's name was subsequently retired and replaced with Gabrielle.
Sources: Bureau of Meteorology report Wikipedia
View full track data (63 observations)
| Date/Time (UTC) | Category | Position | Pressure | Wind |
|---|---|---|---|---|
| 1999-04-02 00:00:00 | 1 | -11.2, 131.0 | 1007 hPa | 10 km/h |
| 1999-04-02 06:00:00 | 1 | -11.2, 130.6 | 1006 hPa | 10 km/h |
| 1999-04-02 12:00:00 | 1 | -11.1, 130.1 | 1006 hPa | 10 km/h |
| 1999-04-02 18:00:00 | 1 | -11.1, 129.7 | 1006 hPa | 13 km/h |
| 1999-04-03 00:00:00 | 1 | -11.0, 129.2 | 1006 hPa | 13 km/h |
| 1999-04-03 06:00:00 | 1 | -11.1, 128.2 | 1005 hPa | 13 km/h |
| 1999-04-03 12:00:00 | 1 | -11.2, 127.2 | 1004 hPa | 13 km/h |
| 1999-04-03 18:00:00 | 1 | -11.2, 126.2 | 1003 hPa | 13 km/h |
| 1999-04-04 00:00:00 | 1 | -11.3, 125.2 | 1002 hPa | 13 km/h |
| 1999-04-04 06:00:00 | 1 | -11.4, 124.2 | 1000 hPa | 15 km/h |
| 1999-04-04 12:00:00 | 1 | -11.7, 123.2 | 998 hPa | 18 km/h |
| 1999-04-04 16:00:00 | 1 | -12.0, 122.6 | 995 hPa | 21 km/h |
| 1999-04-04 18:00:00 | 1 | -12.2, 122.2 | 991 hPa | 21 km/h |
| 1999-04-04 19:00:00 | 1 | -12.3, 122.0 | 990 hPa | 21 km/h |
| 1999-04-04 22:00:00 | 1 | -12.5, 121.4 | 990 hPa | 26 km/h |
| 1999-04-05 00:00:00 | 1 | -12.6, 121.0 | 986 hPa | 28 km/h |
| 1999-04-05 01:00:00 | 1 | -12.6, 120.8 | 985 hPa | 28 km/h |
| 1999-04-05 04:00:00 | 1 | -12.7, 120.3 | 980 hPa | 31 km/h |
| 1999-04-05 06:00:00 | 1 | -12.8, 120.0 | 976 hPa | 33 km/h |
| 1999-04-05 07:00:00 | 1 | -12.9, 119.8 | 975 hPa | 36 km/h |
| 1999-04-05 10:00:00 | 1 | -13.1, 119.4 | 970 hPa | 39 km/h |
| 1999-04-05 12:00:00 | 1 | -13.3, 119.1 | 966 hPa | 41 km/h |
| 1999-04-05 13:00:00 | 1 | -13.4, 118.9 | 965 hPa | 41 km/h |
| 1999-04-05 16:00:00 | 1 | -13.7, 118.3 | 960 hPa | 44 km/h |
| 1999-04-05 18:00:00 | 1 | -13.8, 118.0 | 953 hPa | 46 km/h |
| 1999-04-05 19:00:00 | 1 | -13.9, 117.9 | 950 hPa | 49 km/h |
| 1999-04-05 22:00:00 | 1 | -14.2, 117.6 | 940 hPa | 51 km/h |
| 1999-04-06 00:00:00 | 1 | -14.5, 117.5 | 933 hPa | 57 km/h |
| 1999-04-06 01:00:00 | 1 | -14.7, 117.4 | 930 hPa | 57 km/h |
| 1999-04-06 04:00:00 | 1 | -15.2, 117.1 | 920 hPa | 59 km/h |
| 1999-04-06 06:00:00 | 1 | -15.5, 117.0 | 913 hPa | 62 km/h |
| 1999-04-06 07:00:00 | 1 | -15.6, 116.9 | 910 hPa | 62 km/h |
| 1999-04-06 10:00:00 | 1 | -16.1, 116.8 | 900 hPa | 62 km/h |
| 1999-04-06 12:00:00 | 1 | -16.3, 116.7 | 900 hPa | 62 km/h |
| 1999-04-06 13:00:00 | 1 | -16.4, 116.6 | 900 hPa | 62 km/h |
| 1999-04-06 16:00:00 | 1 | -16.6, 116.4 | 900 hPa | 59 km/h |
| 1999-04-06 18:00:00 | 1 | -16.7, 116.4 | 906 hPa | 57 km/h |
| 1999-04-06 19:00:00 | 1 | -16.8, 116.4 | 910 hPa | 54 km/h |
| 1999-04-06 22:00:00 | 1 | -17.1, 116.5 | 920 hPa | 51 km/h |
| 1999-04-07 00:00:00 | 1 | -17.4, 116.8 | 926 hPa | 49 km/h |
| 1999-04-07 01:00:00 | 1 | -17.5, 116.9 | 930 hPa | 49 km/h |
| 1999-04-07 04:00:00 | 1 | -18.1, 117.3 | 935 hPa | 49 km/h |
| 1999-04-07 05:00:00 | 1 | -18.3, 117.4 | 935 hPa | 49 km/h |
| 1999-04-07 06:00:00 | 1 | -18.5, 117.5 | 940 hPa | 46 km/h |
| 1999-04-07 07:00:00 | 1 | -18.7, 117.6 | 940 hPa | 46 km/h |
| 1999-04-07 08:00:00 | 1 | -18.9, 117.8 | 945 hPa | 46 km/h |
| 1999-04-07 09:00:00 | 1 | -19.1, 117.9 | 945 hPa | 44 km/h |
| 1999-04-07 10:00:00 | 1 | -19.2, 118.0 | 950 hPa | 41 km/h |
| 1999-04-07 11:00:00 | 1 | -19.4, 118.1 | 955 hPa | 41 km/h |
| 1999-04-07 12:00:00 | 1 | -19.5, 118.2 | 960 hPa | 36 km/h |
| 1999-04-07 13:00:00 | 1 | -19.6, 118.4 | 965 hPa | 33 km/h |
| 1999-04-07 14:00:00 | 1 | -19.7, 118.5 | 970 hPa | 31 km/h |
| 1999-04-07 15:00:00 | 1 | -19.9, 118.7 | 975 hPa | 28 km/h |
| 1999-04-07 16:00:00 | 1 | -20.1, 118.8 | 980 hPa | 26 km/h |
| 1999-04-07 17:00:00 | 3 | -20.2, 118.9 | 985 hPa | 21 km/h |
| 1999-04-07 18:00:00 | 2 | -20.3, 119.0 | 990 hPa | 18 km/h |
| 1999-04-07 19:00:00 | 2 | -20.4, 119.1 | 995 hPa | 15 km/h |
| 1999-04-07 20:00:00 | 2 | -20.5, 119.3 | 998 hPa | 15 km/h |
| 1999-04-07 21:00:00 | 2 | -20.6, 119.5 | 999 hPa | 13 km/h |
| 1999-04-07 22:00:00 | 2 | -20.6, 119.7 | 1000 hPa | 13 km/h |
| 1999-04-08 00:00:00 | 2 | -20.4, 120.0 | 1000 hPa | 13 km/h |
| 1999-04-08 01:00:00 | 2 | -20.3, 120.1 | 1001 hPa | 13 km/h |
| 1999-04-08 04:00:00 | 2 | -20.0, 120.6 | 1002 hPa | 13 km/h |