The 1995/96 tropical cyclone season in northwest Australia was one of the busiest recorded. The cyclone season extended from 19 November 1995 through until 7 May 1996. Along the northwest coast of Australia the season spanned the period from 6 December 1995 to 11 April 1996. A total of 9 cyclones were observed in the Perth Tropical Cyclone Warning Centre Region (90°E - 125°E) of which 6 occurred off the northwest coast of Australia (105°E - 125°E). Five of these caused at least gale force winds on the WA coastline and three crossed the coast, including two category 4 storms. This compares with the long term average of 4 cyclones off the northwest coast each season with 2 coastal crossings.
El Nino-Southern Oscillation conditions dominated the northwest Australian region for much of the period 1991 to mid 1995. However the 1995/96 season saw a respite from these conditions and was set against a background of increasing Southern Oscillation Index (SOI) values heralding a transition to weak La Nina conditions.
Details of each Tropical Cyclone in the northwest Australian region 1995-96
Frank (6-11 December 1995)
Frank was the first tropical cyclone to form off the northwest coast of Australia during the 95/96 season and was one of the earliest December cyclones to bring gales on the west Pilbara coast. The only other cyclones to bring gales west of Wallal before Christmas in the years since 1876 have been Beryl (1973), Joan (1975) and Ilona (1988). In contrast to the precursor conditions to Frank, these events all occurred following winters when the SOI values were strongly positive (greater than plus 15).
A tropical low was first observed near 10°S 117°E during the morning of 6 December. The low then tracked southeast and intensified, reaching cyclone strength by the afternoon of 7 December. As further intensification progressed Frank changed direction towards the southsouthwest, maintaining that course until early on 12 December when located just to the west of Cape Cuvier. Frank was at maximum strength around 9 am on 10 December when located at 19.3°S 114.9°E with central pressure estimated to be 950 hPa. Frank remained offshore throughout its lifetime passing closest to land during early evening on 11 December, when the centre was about 70 kilometres west of North West Cape. Gale force winds occurred in the North West Cape region for a period of just over 24 hours commencing on the morning of 11 December. Some minor damage to property occurred at Exmouth. The maximum wind gust recorded at Learmonth Meteorological Office was 111 kilometres per hour.
A study of the foreshore on the western side of Exmouth Gulf showed that a storm surge had occurred, however there was no tide gauge to provide accurate measurements. The debris line along the foreshore suggested that the surge was of the order of 1 metre, however this level may have been influenced by rainwater flowing out into the Gulf.
The cyclone weakened rapidly over colder water during 12 December to below cyclone strength by the evening. The low then recurved towards the southsoutheast passing close to Carnarvon around midnight, then moved inland and weakened further during 13 December. Heavy rain in the Carnarvon area caused damage to plantations.
Gertie (17-20 December 1995)
A tropical low formed in the Timor Sea on 16 December and tracked westsouthwest as it deepened slowly. The low crossed into the WA region on 17 December and was named Gertie on the afternoon of the 18th. The cyclone then moved towards the southsouthwest during the 19th but slowed to be almost stationary during the late afternoon and evening of that day. Gertie then began to move south, then southeastwards, crossing the coast near Mandora at around 0830 WST 20 December. A maximum gust of 145 kilometres per hour and a barometer reading of 969 hPa were recorded at Mandora, with only minor damage resulting. Mandora received 161.8 mm of rain in the 24 hours up to 9am on 21 December. Gertie passed to the northeast of Telfer producing near gale force winds and heavy rain before dissipating on the 21st. There have now been 3 consecutive pre-Christmas coastal crossings along the Eightly Mile Beach.
Isobel (27-29 January 1996)
Following the active period in December most of January was quiet. Isobel formed from a cloud cluster that had moved westsouthwest off the Kimberley coastline. It barely reached cyclone intensity during the afternoon of 29 January and remained a very weak cyclone until 31 January when it was finally sheared apart still well off the Pilbara coastline. It had no impact on the northwest coastal region.
Jacob (1-5 February 1996)
TC Jacob developed from a monsoonal low that moved across the Northern Territory and Kimberley before tracking over the Bonaparte Gulf. It closely followed the WA coast and developed cyclone characteristics near Adele island. Jacob continued to intensify and moved westsouthwestwards, roughly parallel to the Pilbara coast. The cyclone developed a rather large circulation such that gales were reported from the Automatic Weather Stations (AWS) at Bedout and Legendre Islands and at Karratha Airport where the maximum gust recorded was 100 kilometres per hour. Only minor damage occurred. At peak intensity Jacob was a Category 3 storm with wind gusts near the centre estimated to be 200 kilometres per hour. The Kimberley and Pilbara coastal areas received heavy rains as the cyclone passed offshore. Notable daily rainfall totals were reported on the 3rd at Kuri Bay (225.2 mm); and on the 5th at Karratha (106.8 mm), Mardie (86.1mm) and Onslow (83.9 mm).
Kirsty (9-12 March 1996)
Severe tropical cyclone Kirsty crossed the coast at Pardoo Station (100 kilometres east of Port Hedland) at 6am on Tuesday 12 March. The cyclone had followed an erratic southwards path during the previous 2 days, before settling on a southsouthwest track in the 12 hours prior to landfall. The cyclone progressively intensified as it approached land and was at peak intensity as it crossed the coast. Pardoo Station recorded a minimum pressure of 938 hPa as the eye passed over. The cyclone then moved on a more southward track and passed about 50 kilometres to the west of Marble Bar around midday. At Pardoo Station, the homestead received only minor damage but the tourist cabins and other structures were severely damaged. Some stock losses were also reported. Pardoo roadhouse was demolished, and the occupants resorted to taking shelter in the cool-room. Some minor damage occurred at Marble Bar, Nullagine and Newman.
Tropical cyclone Olivia formed in the Timor Sea on Friday 5 April. The cyclone moved on a westwards path and slowly intensified over the next few days. It changed direction towards the south late on 9 April and was upgraded to Category 4. During 10 April the cyclone turned towards the southsoutheast and accelerated towards the west Pilbara coastline. The eye of the cyclone passed directly over the Montebello Islands between 1630 and 1830 WST, over Mardie Station at 2030 WST then tracked just to the west of Pannawonica and Paraburdoo as it accelerated towards the southsoutheast and weakened. The edge of the eye also impinged on the northeast parts of Barrow Island.
Olivia was one of the strongest cyclones to have crossed the Australian coastline in recent decades. The maximum wind gust of 408 kilometres per hour recorded on Barrow Island established a new world record for the highest wind gust ever recorded. In addition Varanus Island measured 267 kilometres per hour and Mardie recorded a wind gust of 257 kilometres per hour. At the time this was the second highest recorded on the Australian mainland, the highest being 259 kilometres per hour also at Mardie, during Trixie in February 1975 (subsequently Vance caused a wind gust of 267 km/h at Learmonth in March 1999).
Other extreme wind gusts previously recorded during Australian cyclones have been:
246 kilometres per hour at Onslow in Trixie,
232 kilometres per hour at Onslow in February 1963 (no name allocated prior to 1964),
222 kilometres per hour at Mandora during Elsie in February 1987,
217 kilometres per hour at Darwin during Tracy in December 1974 and
208 kilometres per hour during Joan at Port Hedland in December 1975.
Olivia was a much larger storm than cyclone Tracy with stronger winds measured at the centre. Winds in the Dampier/Karratha region and at Paraburdoo reached category 2 strength. The maximum gust recorded in the Dampier area during Olivia was 143 kilometres per hour at Dampier Salt. The maximum gust at Paraburdoo was 140 kilometres per hour.
Because the cyclone was moving quickly as it crossed the coast rainfall totals were not excessive. Falls along the path of the cyclone were only slightly greater than 100 millimetres, the highest reported being 117 mm at Yalleen Station to the southeast of Mardie.
A Department of Transport tide gauge located in King Bay showed that a storm surge of just over 2 metres had occurred. Waves in the bay were estimated to have been up to 7 metres. Over the open ocean waves up to 21 metres high were reported from the North Rankin A Gas platform.