1997–98 Australian region cyclone season

Infobox hurricane season
Basin=Aus
Year=1998
Track=1997-1998 Australian cyclone season summary.jpg
First storm formed=November 19, 1997
Last storm dissipated=April 19, 1998
Strongest storm name=Tiffany
Strongest storm pressure=940
Strongest storm winds=93
Average wind speed=10
Total depressions=
Total storms=10 official, 1 unofficial
Total hurricanes=4
Total intense=
Fatalities=
Da

Inflated=
five seasons=1995–96, 1996–97, 1997–98, 1998–99, 1999–00The 1997-98 Australian region cyclone season was an event in the ongoing cycle of tropical cyclone formation. It ran from November 1, 1997 to April 30, 1998. The regional tropical cyclone operational plan also defines a "tropical cyclone year" separately from a "tropical cyclone season", and the "tropical cyclone year" ran from July 1, 1997 to June 30, 1998.

Tropical cyclones in this area were monitored by four Tropical Cyclone Warning Centres (TCWCs): the Australian Bureau of Meteorology in Perth, Darwin, and Brisbane; and TCWC Port Moresby in Papua New Guinea.

__TOC__

torms

Tropical Cyclone Nute

Infobox Hurricane Small
Basin=Aus
Track=Nute 1997 track.pngFormed=November 19
Dissipated=November 21
10-min winds=60
1-min winds=70
Pressure=975Entered the Australian region on November 19 (See 1997-98 South Pacific cyclone season).

Tropical Cyclone Sid

Infobox Hurricane Small
Basin=Aus


Track=Sid 1997 track.pngFormed=December 24
Dissipated=December 29
10-min winds=50
1-min winds=40
Pressure=985A low-pressure system formed over the Northern Territory in late December and moved into the Timor Sea as the monsoon trough developed near Australia. A tropical depression had formed on December 26 near Darwin, Australia. The storm reached gale force six hours after developing and was named Sid by the Tropical Cyclone Warning Center in Darwin. Sid moved to the east, affecting the Northern Territory. Sid turned southestward, crossing the Northern Territory. Sid moved fully southward, in which it weakened due to wind shear. By December 28, Sid had weakened to below gale-status and residual low meandered around for a few days. [http://australiasevereweather.com/cyclones/1998/summ9712.htm#9808 Sid Report] ]

By January 3, the low re-entered the Western Gulf and the TCWC in Darwin began to re-issue advisories on the low, which was forecast to re-intensify. The low became a depression and drifted around for another day. On January 4, scatterometer data at 1330 UTC indicated the presence of 30-35 mph winds over the water. The depression weakened back into a low on January 5 and advisories were stopped again. However, on January 7, the TCWC in Darwin re-issued advisories for a third time and was forecast to re-intensify, but this did not occur. The last warning was issued on the depression at 1800 UTC. The remnant low moved into the Gulf of Carpentaria and across Queensland. The TCWC in Brisbane, Australia issued bulletins on January 10 for the low which was once Sid. The low remained quasi-stationary ro a couple of days near Townsville. The bulletins were discontinued the next day. Heavy rains fell and several rivers flooded when it was the remnant low on January 11. [http://www.australiasevereweather.com/cyclones/1998/summ9801.htm#9808 Tropical Depression (formerly TC Sid - 08S) 3-11 January] ]

evere Tropical Cyclone Selwyn

Infobox Hurricane Small
Basin=Aus


Track=Selwyn 1997 track.pngFormed=December 26
Dissipated=January 2
10-min winds=76
1-min winds=65
Pressure=960Tropical Cyclone Selwyn formed 650 kilometers east-southeast of Christmas Island within the monsoon trough. [http://www.australiasevereweather.com/cyclones/1998/summ9712.txt Tropical Cyclone Selwyn (TC-09S)26 December-2 January] ] Selwyn rapidly strengthened into a tropical cyclone on December 27 and reached its maximum intensity of 70 mph (110 km/h) on December 28. Selwyn went at a west-southwesterly motion, bringing it to a position almost convert|1000|nmi|km|-3 west of Broome by mid-day December 29. After this point, Selwyn began to weaken rapidly as it moved west-northwesterly slowly. Warnings were discontinued by the Tropical Cyclone Warning Center in Perth, Australia on December 31 because winds were forecast to fall below gale-force. The remnant low drifted westward and then to the southwest with convection flaring up once in a while. Warnings were re-issued in early January due to forecasts that Selwyn would re-intensify, but this did not occur. The remnant low (formerly known as Selwyn) was tracked until January 3.

evere Tropical Cyclone Katrina

Infobox Hurricane Small
Basin=Aus


Track=Katrina 1998 track.pngFormed=January 2
Dissipated=January 24
10-min winds=90
1-min winds=90
Pressure=940Cyclone Katrina was one of the longest-lived South Pacific cyclone on record, lasting 24 days while moving erratically east of Australia. Katrina formed on January 1,1998 convert|340|nmi|km|0 east-northeast of Cairns and convert|425|nmi|km|0 southeast of Port Moresby, Papua New Guinea. [http://australiasevereweather.com/cyclones/1998/summ9801.htm#9812 Katrina report] ] Katrina became a tropical storm on January 3 and was moving slowly to the east-northeast. The cyclone was affected by Cyclone Susan which was convert|1000|nmi|km|-2 east of Katrina. On January 7, Susan moved further south allowing Katrina to intensify as it neared the Solomon Islands, this proved to be the northernmost point of Katrina's track as the storm turned east-southeast and then southeast, fluctuating in hurricane strength. On January 9, Cyclone Katrina threatened Vanuatu when it stalled about convert|200|nmi|km|-1 west-northwest of Port Vila and reversed direction and moved west due a high pressure system. On January 11, Katrina moved south of Rennell Island and then crossed back into the Brisbane area six hours later where it crossed the 160E on its eastward journey, then the storm turned west where it maintained that course until January 15. [http://australiasevereweather.com/cyclones/1998/summ9801.htm#9812 Katrina report] ] On the 15th, the storm moved south-southwest where it reached category 2 strength with a barometric pressure of 940 mbar. Katrina weakened rapidly and slowed before making a tight loop on January 17 and January 18 [http://australiasevereweather.com/cyclones/1998/summ9801.htm#9812 Katrina report] ] . After completing the loop, Cyclone Katrina moved east for 12 hours before moving east-southeast for three days. During that time, Katrina briefly reached Category 1 strength once more before slowing down and being affected by wind shear. By January 24, Katrina had weakened to a tropical depression and on January 25, Katrina dissipated convert|250|nmi|km|0 east of Townsville. [http://australiasevereweather.com/cyclones/1998/summ9801.htm#9812 Katrina report] ]

evere Tropical Cyclone Tiffany

Infobox Hurricane Small
Basin=Aus

---

Track=Tiffany 1998 track.pngFormed=January 22
Dissipated=January 31
10-min winds=93
1-min winds=120
Pressure=940Tropical Cyclone Tiffany began as a tropical low about convert|1000|nmi|km|-3 northeast of Broome. [http://australiasevereweather.com/cyclones/1998/summ9801.htm Tropical Cyclone Tiffany (TC-15S) 24-31 January] ] TCWC in Perth, Australia started issuing advisories on the low January 24. The system was of land origin and had entered the ocean. A brief surge of southeasterly flow helped the system strengthen and was given the name Tiffany the next day. Tiffany was a small system and strengthened rapidly with an estimated convert|40|mi/h|km/h|-1|abbr=on gain in a 12-hour period on January 26. Hurricane-status was reached at 1200 UTC about convert|125|nmi|km|0 north of Port Hedland. The peak intensity of 930 millibars was recorded on January 27 with the maximum sustained winds of 115 mph (140 by the JTWC). Tiffany remained at convert|115|mi/h|km/h|0|abbr=on for 18-24 hours before beginning to weaken. The cyclone went to the west-southwest, farther and farther away from the Australian coastline. By January 29, the system fell below hurricane-status and Perth issued its last warning the next day. The Joint Typhoon Warning Center followed the next day. No damage was reported with the system.
* [http://www.bom.gov.au/weather/wa/cyclone/about/seasonsummary199798.shtml Australian Report for Tiffany]

Tropical Cyclone Les

Infobox Hurricane Small
Basin=Aus
Track=Les 1998 track.pngFormed=January 23
Dissipated=February 1
10-min winds=60
1-min winds=50
Pressure=976Les formed on January 23, 1998 near Darwin, Australia. The storm moved westward reaching Category 1 status before making landfall on the eastern gulf coast of the Northern Territory. Moving back out over the Timor Sea, Les hugged the coast and regained strength before making a second landfall and dissipating. Les caused extensive flooding and damage in the town of Katherine and there was one death. [ [http://australiasevereweather.com/cyclones/1998/summ9801.htm#9812 Les Report] ]

evere Tropical Cyclone Victor-Cindy

Infobox Hurricane Small
Basin=Aus
Track=Victor-Cindy 1998 track.pngFormed=February 10
Dissipated=February 15
10-min winds=64
1-min winds=90
Pressure=970A low, possibly from Cyclone Katrina, continued to move to the west across Northern Australia and emerged in the Indian Ocean where it strengthened into Cyclone Victor in early February. [http://www.bom.gov.au/weather/wa/cyclone/about/seasonsummary199798.shtml WA Tropical Cyclone Season Summary 1997-98] ] The weakening Tropical Cyclone Victor accelerated to the middle of the Indian Ocean where it was again renamed Cindy by the Mauritius Tropical Cyclone Warning Centre, and then finally weakened on 17 February. The time from the beginning of Cyclone Katrina to the ending of Cyclone Cindy was around 50 days.

Tropical Cyclone May

Infobox Hurricane Small
Basin=Aus
Track=May 1998 track.pngFormed=February 25
Dissipated=February 26
10-min winds=41
1-min winds=35
Pressure=990May formed from an area of low pressure on February 25,1998 near the Australian coast. May moved southward before making landfall near Mornington Island on February 26. After that the storm dissipated while moving inland. [ [http://australiasevereweather.com/cyclones/1998/summ9802.htm#9825 May report] ] There were no reports of deaths or damage from Tropical Storm May.

Tropical Cyclone Nathan

Infobox Hurricane Small
Basin=Aus

---

Track=Nathan 1998 track.pngFormed=March 20
Dissipated=March 26
10-min winds=50
1-min winds=65
Pressure=990Tropical Cyclone Nathan formed from a tropical low embedded weak monsoon trough that had formed when Tropical Cyclone Yali had reached cyclone intensity. Upper-level outflow was favorable, but wind shear made it restricted for rapid development. Nathan started off developing rapidly, the first warning, issued on March 21, classified the system as a convert|45|mi/h|km/h|0|abbr=on tropical cyclone. Nathan was a small system in an environment of weak steering flow, causing the storm to move erattically but slowly to the east. Nathan turned southward, coming to within convert|100|nmi|km|-1 of Cooktown, Australia on March 23. The TCWC in Brisbane kept Nathan's wind speed at 50-60 mph, whereas the Joint Typhoon Warning Center boosted it up to hurricane-strength on March 23.

After approaching the coast of Queensland, Nathan came under the influence of the monsoon flow from Tropical Cyclone Yali. The storm moved east-northeasterly very rapidly and became more easterly on March 25. By the morning of March 26, the circulation was becoming sheared. The shear was possibly coming from an extratropical system (formerly known as Yali). Nathan turned to the south and the Brisbane TCWC downgraded the system into a tropical low, ceasing advisories. By 1200 UTC on March 27, Nathan showed signs of redevelopment near the Chesterfield Islands. The JTWC reissued advisories and upped the winds to convert|50|mi/h|km/h|-1|abbr=on. Nathan moved westward and approached Australia again, weakening slowly.

A scatterometer pass on March 29 indicated a small circulation with winds of about convert|40|mi/h|km/h|-1|abbr=on and a Willis Island report the next day indicated that Nathan only had convert|35|mi/h|km/h|0|abbr=on easterly winds. The JTWC kept Nathan as a minimal tropical cyclone until March 31 when it was downgraded into a weakening low.

Tropical Cyclone Yali

Infobox Hurricane Small
Basin=Aus
Track=Yali 1998 track.pngFormed=March 25
Dissipated=March 27
10-min winds=42
1-min winds=50Entered the Australian region on March 25 (See 1997-98 South Pacific cyclone season).

Tropical Low (35S)

Infobox Hurricane Small
Basin=Aus
Type1=low
Formed=April 19
Dissipated=April 19
10-min winds=35
1-min winds=40
Pressure=1002A low formed off the coast of Australia on April 16, 1998. The depression moved southwestward before making landfall in Western Australia on the 19th. [ [http://australiasevereweather.com/cyclones/1998/summ9804.htm#9835 35S report] ] There were reports of heavy rain but no report of damage or deaths from the unnamed storm.

torm names

Tropical cyclones are assigned names by the Australian Bureau of Meteorology or Papua New Guinea. Tropical cyclones are named if they are non-frontal low pressure systems of synoptic scale developing over warm waters, or if Dvorak intensity analysis indicate the presence of gale force or stronger winds near the centre. Therefore, tropical systems with gales in one or more quadrants, but not near the centre, are not named.cite web|title=Tropical Cyclones: Frequently Asked Questions|accessdate=2008-08-15|publisher=Australian Government Bureau of Meteorology|url=http://www.bom.gov.au/weather/cyclone/faq/index.shtml] All names assigned in the Australian region are selected sequentially. Only the names used during this cyclone season are listed below. The complete list of names for each basin are found in the World Meteorological Organization's official lists.cite web|year=1999|title=Tropical Cyclone Operational Plan for the South Pacific and South-East Indian Ocean|accessdate=2008-08-15|publisher=World Meteorological Organization|url=http://www.wmo.ch/pages/prog/www/Peng/tcp/documents/doc/Op-pln99.doc]

Each Australian Tropical Cyclone Warning Centre (Perth, Darwin, and Brisbane) maintains a list of names arranged alphabetically and alternating male and female. Tropical cyclones that develop in the South-East Indian Ocean are assigned names by the Tropical Cyclone Warning Centre in Perth. This region includes the areas east of 90°E, south of the Equator, and west of 125°E. Tropical cyclones that develop south of the Equator between 125°E and 141°E are assigned names by the Tropical Cyclone Warning Centre in Darwin, Northern Territory. This area includes most of the cyclones that form in the Arafura Sea and Western Gulf of Carpentaria. Tropical cyclones in the Coral Sea and Eastern Gulf of Carpentaria between 141°E and 160°E and south of 10°S are assigned names by the Tropical Cyclone Warning Centre in Brisbane, Queensland.

Additionally, the Tropical Cyclone Warning Centre in Port Moresby, Papua New Guinea reserves the right to name cyclones that develop in the Solomon Sea and Gulf of Papua, north of 10°S between 141°E and 160°E. Names are selected randomly from their list and retired once they are used.cite web|year=2006|title=Tropical Cyclone Operational Plan for the South Pacific and South-East Indian Ocean|accessdate=2008-08-15|publisher=World Meteorological Organization|url=http://www.wmo.int/pages/prog/www/tcp/documents/TCP-24-OP-PLN-2006-edition-english.pdf] No cyclones were named by this warning centre during the 1997-98 season.

Perth
* Selwyn - Tiffany - Victor

Darwin
* Sid

Brisbane
* Katrina - Les - May - Nathan

Additionally, two cyclones that were named by Fiji Meteorological Service - Nute and Yali - moved into Brisbane's area of responsibility.

ee also

*List of Southern Hemisphere cyclone seasons
*Atlantic hurricane seasons: 1997, 1998
*Pacific hurricane seasons: 1997, 1998
*Pacific typhoon seasons: 1997, 1998
*North Indian Ocean cyclone seasons: 1997, 1998

References

External links

* [https://metocph.nmci.navy.mil/jtwc.html Joint Typhoon Warning Center (JTWC)] .
* [http://www.bom.gov.au/weather/cyclone/index.shtml Australian Government Bureau of Meteorology] .
* [http://www.wmo.int/index-en.html World Meteorological Organization]
* [http://ftp.wmo.int/pages/prog/www/Peng/TCP_vO/Reports/7RAVTCC.doc RA V Tropical Cyclone Committee Final Report]
* [http://metocph.nmci.navy.mil/jtwc/atcr/1998atcr/pdf.html Joint Typhoon Warning Center 1998 ATCR]
* [ftp://ftp.bom.gov.au/anon2/home/ncc/cyclone/cyclones_newformat.zip Raw cyclone track data]
* [http://www.bom.gov.au/inside/services_policy/public/sigwxsum/sigwmenu.shtml BoM Monthly Significant Weather Summaries]
* [http://www.bom.gov.au/weather/wa/cyclone/about/seasonsummary199798.shtml 1997-98 Annual Summary (Western Australia)]
* [http://australiasevereweather.com/cyclones/tropical_cyclones_1998_summaries_and_track_data.htm September 1997 to June 1998 Tropical Cyclone Summaries and Operational Track Data]