Langbahn Team – Weltmeisterschaft

Cyclone Herbie

Tropical Cyclone Herbie
Cyclone Herbie approaching Western Australia on 20 May
Meteorological history
Formed17 May 1988
Dissipated21 May 1988
Category 1 tropical cyclone
10-minute sustained (Aus)
Highest winds75 km/h (45 mph)
Highest gusts120 km/h (75 mph)
Lowest pressure990 hPa (mbar); 29.23 inHg
Tropical storm
1-minute sustained (SSHWS/JTWC)
Highest winds65 km/h (40 mph)
Overall effects
FatalitiesNone reported
Damage$15.6 million (1988 USD)
Areas affectedWestern Australia
IBTrACSEdit this at Wikidata
Part of the 1987–88 Australian region cyclone season

Tropical Cyclone Herbie was the only known tropical system to impact Western Australia during the month of May on record. The final cyclone of the 1987–88 Australian region cyclone season, Herbie was first identified northwest of the Cocos Islands on 17 May. The following day, the system was classified as a tropical low by the Australian Bureau of Meteorology and intensified into a Category 1 cyclone later that day. Several hours after this upgrade, the storm attained its initial peak intensity with winds of 75 km/h (45 mph 10-minute sustained). Around the same time, the Joint Typhoon Warning Center classified Herbie as Tropical Storm 21S.

On 19 May, the cyclone formed a new low-pressure center and relocated roughly 300 km (190 mi) south. Shortly thereafter, the storm began to accelerate towards the southeast and started to undergo an extratropical transition. Early on 21 May, Herbie made landfall in Shark Bay before losing its identity the following day over the Great Australian Bight. Although a weak storm, Herbie brought flooding rains and severe dust storms to portions of Western Australia. Additionally, a 30,000 ton freighter broke in half amidst rough seas produced by the storm. Total losses from the storm reached A$20 million (US$15.6 million). Due to the significant damage wrought by Herbie, the name was retired following its use.

Meteorological history

Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
Map key
Saffir–Simpson scale
  Tropical depression (≤38 mph, ≤62 km/h)
  Tropical storm (39–73 mph, 63–118 km/h)
  Category 1 (74–95 mph, 119–153 km/h)
  Category 2 (96–110 mph, 154–177 km/h)
  Category 3 (111–129 mph, 178–208 km/h)
  Category 4 (130–156 mph, 209–251 km/h)
  Category 5 (≥157 mph, ≥252 km/h)
  Unknown
Storm type
triangle Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

Tropical Cyclone Herbie originated from an area of low pressure on 17 May 1988 northwest of the Cocos Islands. Later that day, the Australian Bureau of Meteorology began monitoring the system as a tropical low.[1] Several hours after, the Joint Typhoon Warning Center (JTWC) classified the system as Tropical Depression 21S, having attained winds of 45 km/h (30 mph 1-minute sustained).[2] Following slight development, the system intensified into a Category 1 cyclone and was given the name Herbie by the Australian Bureau of Meteorology early on 18 May.[1][3] Several hours after being named, the storm attained its initial peak intensity with winds of 75 km/h (45 mph 10-minute sustained) and a barometric pressure of 990 hPa (mbar).[3]

Around the same time, the JTWC upgraded the system to a tropical storm, estimating the cyclone to have attained peak winds of 65 km/h (40 mph 1-minute sustained).[2] On 19 May, satellite imagery of the system depicted that a new low pressure centre had developed roughly 300 km (190 mi) south of the original low.[1] Several hours after the relocation, the JTWC downgraded Herbie to a tropical depression as the system's movement began to accelerate towards the southeast.[1][2] As the storm moved at a rapid speed towards the coastline of Western Australia, it began to undergo an extratropical transition. During a 24-hour period (20–21 May) Herbie tracked roughly 1,500 km (930 mi), with the movement of the storm reaching 70 km/h (43 mph) at times.[1]

Late on 20 May, the JTWC ceased advisories on the system as it weakened below tropical depression status offshore.[2] However, the Bureau of Meteorology continued to monitor the system. Early on 21 May, the center of Herbie made landfall in Shark Bay with wind gusts up to 120 km/h (75 mph) and a pressure of 980 hPa (mbar). Due to the rapid movement of the storm, it reached the Great Australian Bight while retaining tropical characteristics despite its low-latitude. Early on 22 May, the system lost its identity south of Australia as an extratropical cyclone.[1]

Impact

Although a weak storm, its fast approach allowed for little preparation. According to officials in the coastal town of Denham, "..the cyclone struck virtually without warning." Most tourists staying in the region evacuated the day before Herbie's arrival.[4] Herbie caused moderate structural damage across Western Australia in coastal areas between Carnarvon and Denham. Banana plantations within this area also sustained extensive damage.[1] In Denham, a storm surge of 2 m (6.6 ft) broke the town's retaining wall and flooded low-lying areas along the shore.[1][5] Several fishing vessels were brought inland by the surge and left beached on streets once the water subsided.[1] About 15 homes in Denham lost their roofs after wind gusts estimated at 160 km/h (99 mph) battered the town.[4][6] Due to the storms extratropical transition, areas south of Herbie received moderate to heavy rainfall while areas north of the center reported severe dust storms fueled by the cyclone's high winds. Most areas affected by the storms rain recorded around 50 mm (2.0 in) with isolated totals near 100 mm (3.9 in).[1] The Irwin and Greenough Rivers overflowed their banks, inundating parts of Dongara.[7] In all, the storm wrought approximately A$20 million worth of structural and agricultural damage in Western Australia.[8]

Offshore, a 30,000 ton freighter, the MV Korean Star, sustained extreme damage during the storm. Rough seas caused the hull of the ship to break and the vessel was separated into two pieces. Although the freighter was in two pieces, the ship did not sink and the wreckage of it came ashore near Cape Cuvier.[1] No one on the ship sustained injury as all 19 crew members abandoned ship.[9] The crew was rescued within a day of sustaining the damage and flown to Carnarvon.[4]

In the wake of the storm, the town hall in Denham was converted into a temporary shelter for the homeless.[6] Repair to damaged roofs and downed power lines began on 22 May.[4] Within a few days of the storm's passage, appeals were made for relief funds in regions affected by Herbie.[10] Although the storm caused relatively little damage, the name Herbie was retired following its usage and will never be used again to name a tropical cyclone in the Australian region.[11]

References

  1. ^ a b c d e f g h i j k "Tropical Cyclone Herbie". Australian Bureau of Meteorology. 2010. Retrieved 27 January 2010.
  2. ^ a b c d Joint Typhoon Warning Center (1989). "Cyclone 21S Best Track". United States Navy. Retrieved 27 January 2010.[permanent dead link‍]
  3. ^ a b "Australian Region Tropical Cyclone Best Tracks". Australian Bureau of Meteorology. 2009. Retrieved 27 January 2010.
  4. ^ a b c d Australian Associated Press (22 May 1988), "Cyclone Devastates Town", Sunday Tasmanian
  5. ^ "Clean-Up Begins After Storm Hits WA", Courier Mail, 23 May 1988
  6. ^ a b Unattributed (22 May 1988), "Herbie Makes 'A Real Mess' of WA Town", The Sydney Morning Herald
  7. ^ "Tropical Cyclones Affecting Geraldton". Australian Bureau of Meteorology. Retrieved 27 January 2010.
  8. ^ Unattributed (23 May 1988). "Oil Slick Spreads From Shipwreck". The Sydney Morning Herald.
  9. ^ "Ship breaks up". Herald-Journal. Associated Press. 24 May 1988. Retrieved 27 January 2010.
  10. ^ "Previous Relief Appeals". The Lord Mayor's Distress Relief Fund. 2010. Archived from the original on 7 November 2002. Retrieved 27 January 2010.
  11. ^ "Tropical Cyclone Names". Australian Bureau of Meteorology. 2010. Retrieved 27 January 2010.

Quelle: http://en.wikipedia.org/wiki/Cyclone_Herbie