THELMA

1998-99 season · AU199899_03U

Category 3

History

Severe Tropical Cyclone Thelma developed in the Timor Sea approximately 350 kilometres north of Darwin on 6 December 1998, after a low-pressure system moved into the area in early December. The system intensified at roughly twice the average rate for tropical cyclones, escalating from Category 2 to Category 5 on the Australian scale within just two days of being named. At its peak on 8 December, Thelma recorded a minimum central pressure of 920 hPa and maximum wind gusts of 320 km/h, making it one of the most intense cyclones ever observed off the Australian coast and the first known Category 5 system in the Timor Sea.

Thelma passed approximately 200 kilometres from Darwin, posing the most serious threat to the city since Cyclone Tracy in 1974. It then tracked southwest across the Timor Sea before making landfall on the north Kimberley coast northwest of Kuri Bay early on 11 December as a Category 3 system. It subsequently weakened as it moved inland through the Kimberley and Pilbara regions before dissipating.

Despite its extreme intensity, overall damage was relatively limited. Impacts included communications and power disruptions on the Tiwi Islands, vegetation damage, localised flooding around Darwin — where a record 425 mm fell in 24 hours at Howard Springs — and structural damage to BHP facilities at Troughton Island. Around 120 residents were evacuated from Kalumburu. One fatality was associated with the storm; the remains of an elderly man believed swept away by floodwaters were found ten months later. The name Thelma was subsequently retired.

Sources: Bureau of Meteorology report Wikipedia

View full track data (83 observations)
Date/Time (UTC)CategoryPositionPressureWind
1998-12-01 00:00:00 1 -12.0, 138.0 1007 hPa 8 km/h
1998-12-01 06:00:00 1 -11.9, 137.6 1004 hPa 8 km/h
1998-12-01 12:00:00 1 -11.8, 137.2 1007 hPa 8 km/h
1998-12-01 18:00:00 1 -11.5, 136.8 1005 hPa 8 km/h
1998-12-02 00:00:00 1 -11.2, 136.4 1007 hPa 8 km/h
1998-12-02 06:00:00 1 -11.1, 136.1 1005 hPa 8 km/h
1998-12-02 12:00:00 1 -10.9, 135.9 1007 hPa 8 km/h
1998-12-02 18:00:00 1 -10.7, 135.7 1005 hPa 8 km/h
1998-12-03 00:00:00 1 -10.4, 135.4 1007 hPa 8 km/h
1998-12-03 06:00:00 1 -10.3, 135.0 1004 hPa 8 km/h
1998-12-03 12:00:00 1 -10.2, 134.7 1006 hPa 8 km/h
1998-12-03 18:00:00 1 -10.1, 134.4 1004 hPa 8 km/h
1998-12-04 00:00:00 1 -10.0, 134.0 1006 hPa 8 km/h
1998-12-04 06:00:00 1 -9.9, 133.5 1004 hPa 8 km/h
1998-12-04 12:00:00 1 -9.7, 133.0 1004 hPa 10 km/h
1998-12-04 18:00:00 1 -9.6, 132.6 1002 hPa 10 km/h
1998-12-05 00:00:00 1 -9.5, 132.3 1004 hPa 13 km/h
1998-12-05 06:00:00 1 -9.3, 131.9 1000 hPa 13 km/h
1998-12-05 09:00:00 1 -9.2, 131.6 1000 hPa 13 km/h
1998-12-05 12:00:00 1 -9.1, 131.3 1000 hPa 13 km/h
1998-12-05 15:00:00 1 -9.1, 131.3 998 hPa 13 km/h
1998-12-05 18:00:00 1 -9.1, 131.3 996 hPa 13 km/h
1998-12-05 21:00:00 1 -9.1, 131.3 996 hPa 15 km/h
1998-12-06 00:00:00 1 -9.2, 131.3 994 hPa 15 km/h
1998-12-06 03:00:00 1 -9.2, 131.3 992 hPa 18 km/h
1998-12-06 06:00:00 1 -9.2, 131.3 990 hPa 21 km/h
1998-12-06 09:00:00 1 -9.2, 131.3 985 hPa 23 km/h
1998-12-06 12:00:00 1 -9.2, 131.2 985 hPa 26 km/h
1998-12-06 15:00:00 1 -9.2, 131.2 980 hPa 26 km/h
1998-12-06 18:00:00 1 -9.2, 131.2 980 hPa 28 km/h
1998-12-06 21:00:00 1 -9.3, 131.2 978 hPa 31 km/h
1998-12-07 00:00:00 1 -9.4, 131.2 975 hPa 33 km/h
1998-12-07 03:00:00 1 -9.6, 131.2 975 hPa 36 km/h
1998-12-07 06:00:00 1 -9.9, 131.1 970 hPa 39 km/h
1998-12-07 09:00:00 1 -10.0, 131.0 960 hPa 41 km/h
1998-12-07 12:00:00 1 -10.3, 130.9 955 hPa 46 km/h
1998-12-07 15:00:00 1 -10.6, 130.7 950 hPa 51 km/h
1998-12-07 18:00:00 1 -10.8, 130.4 945 hPa 54 km/h
1998-12-07 21:00:00 1 -10.9, 130.1 945 hPa 57 km/h
1998-12-08 00:00:00 1 -10.9, 130.0 940 hPa 57 km/h
1998-12-08 03:00:00 1 -11.2, 129.8 935 hPa 57 km/h
1998-12-08 06:00:00 1 -11.4, 129.6 930 hPa 59 km/h
1998-12-08 09:00:00 1 -11.5, 129.4 925 hPa 62 km/h
1998-12-08 12:00:00 1 -11.6, 129.2 920 hPa 62 km/h
1998-12-08 15:00:00 1 -11.7, 128.9 920 hPa 62 km/h
1998-12-08 18:00:00 1 -11.7, 128.7 920 hPa 62 km/h
1998-12-08 21:00:00 1 -11.7, 128.5 920 hPa 62 km/h
1998-12-09 00:00:00 1 -11.8, 128.4 920 hPa 59 km/h
1998-12-09 03:00:00 1 -12.0, 128.2 920 hPa 57 km/h
1998-12-09 06:00:00 1 -12.1, 128.0 925 hPa 57 km/h
1998-12-09 09:00:00 1 -12.2, 127.7 925 hPa 57 km/h
1998-12-09 12:00:00 1 -12.4, 127.4 925 hPa 57 km/h
1998-12-09 15:00:00 1 -12.6, 127.1 925 hPa 57 km/h
1998-12-09 18:00:00 1 -12.8, 126.9 930 hPa 57 km/h
1998-12-09 21:00:00 1 -12.9, 126.7 930 hPa 57 km/h
1998-12-10 00:00:00 1 -13.0, 126.4 930 hPa 57 km/h
1998-12-10 03:00:00 1 -13.2, 126.1 930 hPa 57 km/h
1998-12-10 06:00:00 1 -13.4, 125.9 935 hPa 57 km/h
1998-12-10 09:00:00 1 -13.6, 125.7 935 hPa 57 km/h
1998-12-10 12:00:00 1 -13.8, 125.6 935 hPa 51 km/h
1998-12-10 15:00:00 1 -14.1, 125.5 945 hPa 51 km/h
1998-12-10 18:00:00 1 -14.4, 125.2 950 hPa 46 km/h
1998-12-10 21:00:00 1 -14.7, 125.2 960 hPa 39 km/h
1998-12-11 00:00:00 3 -15.0, 125.1 970 hPa 33 km/h
1998-12-11 03:00:00 2 -15.5, 125.0 975 hPa 31 km/h
1998-12-11 06:00:00 2 -15.8, 125.0 980 hPa 26 km/h
1998-12-11 09:00:00 2 -16.1, 125.0 985 hPa 23 km/h
1998-12-11 12:00:00 2 -16.3, 125.0 990 hPa 18 km/h
1998-12-11 15:00:00 2 -16.5, 125.0 995 hPa 15 km/h
1998-12-11 18:00:00 2 -16.9, 124.8 996 hPa 13 km/h
1998-12-12 00:00:00 2 -17.3, 124.7 — 13 km/h
1998-12-12 06:00:00 2 -17.8, 124.4 — 13 km/h
1998-12-12 12:00:00 2 -18.3, 124.0 — 13 km/h
1998-12-12 18:00:00 2 -18.7, 123.5 — 13 km/h
1998-12-13 00:00:00 2 -19.0, 122.8 — 13 km/h
1998-12-13 06:00:00 2 -19.1, 122.3 — 13 km/h
1998-12-13 12:00:00 2 -19.2, 121.8 — 13 km/h
1998-12-13 18:00:00 2 -19.3, 121.3 — 13 km/h
1998-12-14 00:00:00 2 -19.5, 120.8 — 13 km/h
1998-12-14 06:00:00 2 -19.6, 120.4 — 13 km/h
1998-12-14 12:00:00 2 -19.8, 119.9 — 13 km/h
1998-12-14 18:00:00 2 -20.0, 119.6 — 13 km/h
1998-12-15 00:00:00 2 -20.1, 119.4 — 13 km/h