There were a total of eight Tropical Cyclones (TCs) in the Perth TCWC area of responsibility from July 2007 to June 2008. Of these, Melanie, Nicholas, Ophelia and Pancho occurred in the Northwest region between 110-125°E. Pancho and Nicholas were the only severe TCs (category 3 or higher), Pancho reaching category 4 intensity. The only TC to cross the Western Australian coastline was Nicholas as a weak category 1 cyclone south of Coral Bay on the upper west coast, although there was only minimal damage.
The most significant impacts were the financial losses associated with the disruption to industry during Melanie, Nicholas, Ophelia and Pancho. These losses amounted to many hundreds of millions of dollars.
Both Nicholas and Pancho produced heavy rainfall. Nicholas caused heavy rainfall in the west Gascoyne, Murchison and adjacent areas. Pancho caused heavy rainfall in the west Pilbara and Gascoyne, while the remnants of Pancho also caused unseasonal rainfall in the southwest of the state. Strong winds also caused some minor damage near Monkey Mia.
TCs Lee, Rosie, Durga and an Unnamed TC all occurred west of 110°E. Rosie passed close to Christmas Island causing large swells and some damage around the Port.
Aside from the Unnamed TC in July 2007, a TC occurred in every month from November to April - Lee in November; Melanie in December-January; Nicholas in February; Ophelia in February-March; Pancho in March; and Rosie and Durga in April.
Details of each Tropical Cyclone in the northwest Australian region 2007-08
Unnamed Tropical Cyclone 29-30 July 2007
An out of season tropical low briefly reached cyclone intensity near 90°E but was not named operationally. Intensification was assisted by warmer than average sea surface temperatures exceeding 28°C, favourable low level shear and strong upper level outflow associated with the approach of a mid-latitude trough to the south. The estimate of cyclone intensity being reached was strongly influenced by Quickscat imagery rather than conventional Dvorak estimates. This was only the second tropical cyclone to be recorded in July in the Australian region since satellite records commenced. There was no known impact from this event.
For full details see full pdf report (117kB).
Tropical Cyclone Lee 11-15 November 2007
On 11 November a weak low developed in the monsoon trough, approximately 800 km to the north of Cocos Islands. Over the next three to four days, the system drifted slowly towards the south southwest, and reached cyclone intensity at 1800 UTC 14 November, when it was about 700 km to the west northwest of Cocos Islands. Tropical Cyclone Lee continued to intensify, reaching category two intensity at 0000 UTC 15 November, and crossed 90°E into La Reunion's area of responsibility at 0600 UTC 15 November.
Once west of 90°E, the cyclone was renamed Ariel. The cyclone remained at category two intensity for about another two days as it drifted slowly westward, and thereafter rapidly weakened to below cyclone intensity.
For full details see pdf report (624kB).
Tropical Cyclone Melanie 26 December 2007 - 2 January 2008
A developing low formed near Sumba Island on December 27 and moved southwards. The low reached tropical cyclone intensity at 0900 WDT 28 December 2007 and reached category 2 at 0300 WDT 28 December 2007. After its initial southerly motion Melanie turned to the west southwest and moved parallel to the Pilbara coastline until 31 December 2007. The system weakened to category 1 as it turned more southerly and finally weakened to below cyclone strength early on 2 January 2008, dissipating over the ocean well offshore from Exmouth later that day.
Throughout the event forecasts indicated the most likely track would have Melanie remain off the coast, although at times the uncertainty area did indicate that landfall was possible. It was for this reason that Advices were issued for a period while Melanie was offshore from the Pilbara coastline. However based on Bureau advice Emergency Management authorities did not issue community alerts for coastal communities.
Melanie did remain far enough offshore to not to have any direct impact on the WA coast. However, there was a significant economic impact to industry resulting from port closures, production shut downs and evacuations from offshore installations. Preliminary information suggests these costs amounted to hundreds of millions of dollars.
For full details see pdf report (91kB).
Severe Tropical Cyclone Nicholas 11 - 20 February 2008
A low that developed off the Kimberley coast on 11 February reached cyclone strength late on 12 February. The system experienced a period of weakening during 13 February as it began to move to the south east before re-intensifying to cyclone strength and moving in a south westerly direction, executing a loop in its track.
Nicholas then continued in a south westerly direction, paralleling the Pilbara coastline and intensifying to category 3 strength. Nicholas began to weaken to the north of Exmouth before turning to the south and then south east, finally crossing the upper west coast approximately 60 kilometres south southwest of Coral Bay on the morning of 20 February. Nicholas was a category 1 cyclone as it crossed the coast and dissipated to below cyclone strength some 6 hours later.
Nicholas was an unusually slow moving system, the average speed of movement until 16 February was between 4 and 10 km/h. In the later stages the speed increased to about 10 to 13 km/h. The system was also long lived, lasting nine days as a cyclone.
Heavy rain fell through the west Gascoyne and Murchison extending into the adjacent Goldfields and northern parts of the South West Land Division. There were scattered falls in excess of 100 mm and Burnerbinmah in the Murchison recorded 203 mm of rain over three days.
Advices were issued for the Kimberley coastline as Nicholas formed. The watch/warning area was moved down the Pilbara coastline as Nicholas tracked south westerly and FESA issued community alerts for the appropriate communities. The impact to industry was significant with Nicholas affecting, at differing times, the entire Pilbara coastline and offshore rigs for a total period of 10 days.
For full details see pdf report (616kB).
Tropical Cyclone Ophelia 1 - 6 March 2008
A low moved from the Northern Territory across the north Kimberley then developed after moving off the northwest Kimberley coast on the morning of 1 March reaching cyclone intensity that evening about 80 km north of Cape Leveque. The midget cyclone Ophelia quickly developed to category 2 intensity on the morning of 2 March Ophelia and remained a category 2 cyclone through to 5 March as it moved to the west to west southwest well off the Pilbara coast. Ophelia then weakened as it changed track to the south southwest and finally weakening below cyclone intensity late on 6 March well west of Carnarvon (see figure 5.1).
Although advices were issued for the Kimberley coast north of Broome prior to Ophelia moving away from the coast, there were no community alerts issued and no impact to coastal areas. Some offshore industry installations were evacuated as a precautionary measure resulting in some economic losses, however the confidence in the forecast track allowed coastal and near coastal facilities to continue operations during the cyclone event.
For full details see pdf report (288kB).
Severe Tropical Cyclone Pancho 23 - 30 March 2008
A low formed in the Indian Ocean during an active phase of the monsoon trough which developed into Pancho by 25 March 2008. Pancho quickly intensified under favourable conditions as it moved in a south southeasterly direction towards the Western Australian coastline. The system reached category 4 intensity on 26 March before rapidly weakening as it experienced increased wind shear and moved over cooler sea surface temperatures (SST's).
Pancho was associated with heavy rainfall in the west Pilbara and Gascoyne. The remnants of Pancho moved further south passing near Perth on 31 March and resulting in heavy unseasonal rain across the southwest. The heavy rain was generally welcomed by pastoralists and farmers.
For full details see pdf report (676kB).
Tropical Cyclone Rosie 20-24 April 2008
Rosie was a small cyclone that developed rapidly overnight from 21 to 22 April quickly reaching category 2 intensity before weakening as it passed near Christmas Island.
The most significant impact was the heavy swell at high tide at the port area of Christmas Island at about 0000 UTC on 22 April. The Harbour master reported waves of 5-7 m that damaged some facilities on the shore and tore a long-line mooring from its anchor.
This was the first tropical low monitored by the newly established Jakarta Tropical Cyclone Warning Centre (TCWC). While it was named by Perth TCWC once it moved south of 10°S, the reanalysis shows it reached cyclone intensity just north of 10°S in Jakarta TCWC's area of responsibility.
For full details see pdf report (693kB).
Tropical Cyclone Durga 20-26 April 2008
A low which formed in an active monsoon trough during 20 April moved southeast and reached cyclone intensity on 22 April. This was the first tropical low named by the newly established Jakarta Tropical Cyclone Warning Centre (TCWC). It crossed into Australia's area of responsibility late on 23 April and weakened below cyclone strength by the morning of 25 April.
For full details see pdf report (523kB).