Cyclone Nancy

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Severe tropical cyclone Nancy
Category 4 cyclone ( Australian scale )
Category 4 cyclone ( SSHWS )
Cyclone Nancy on February 15th
Cyclone Nancy on February 15th
Emergence February 10, 2005
resolution February 17, 2005
Peak wind
speed
175  km / h (110  mph ) (10 minutes sustained)
230  km / h (145  mph ) (sustained for 1 minute)
Lowest air pressure 935  hPa ( mbar )
dead None reported
Property damage Unknown
Affected
areas 		Cook Islands and American Samoa
Season overview:
South Pacific cyclone season 2004–2005

Cyclone Nancy was the second in a series of four severe tropical cyclones in February 2005 in the Cook Islands . Nancy evolved from a depression on February 10th and quickly organized into a small but intense tropical cyclone. After an explosive intensification , the cyclone reached category 4 on the Australian scale, with sustained ten-minute wind speeds of 175 km / h and a minimum air pressure of 935 hPa. In the course of the following day, emerging wind shear weakened the storm quickly. It transisted into an extra-tropical cyclone on February 17th, which was absorbed by Cyclone Olaf shortly afterwards .

Cyclone Nancy caused significant damage in the Cook Islands, which had already been hit by Cyclone Meena in early February. Several houses on the islands were damaged and destroyed, power lines torn down and fallen trees cut off power and blocked roads. Floods were reported from the coastal areas. As a result of the effects of the storm, the World Meteorological Organization removed the name Nancy from the list of tropical cyclone names and replaced it with Nat .

Storm course

Nancy Railway

Cyclone Nancy emerged on February 10th from an extensive low pressure area within the monsoon channel northeast of Samoa . First, the system remained almost stationary in a zone of weak flow control, low shear and high water temperatures of about 30  ° C . On February 11, a trough briefly increased the wind shear in the area of ​​the system and its twin, the precursor system to Cyclone Olaf located nearby . At 6:00 a.m. UTC on February 12, the outflow from the system had improved and a small area of ​​deep atmospheric convection developed over the center of circulation. During the day, the Regional Specialized Meteorological Center (RSMC) in Nadi , Fiji upgraded the system to a Category 1 cyclone on the Australian scale and named it Nancy when it was located approximately 485 km east-northeast of Pago Pago in American -Samoa found. At that time, the Joint Typhoon Warning Center (JTWC) had also started issuing storm warnings and was running the system under the designation 18P .

The storm initially moved slowly to the northeast in the early hours of February 13, before turning to the southeast due to a subtropical ridge northeast of the system. Rain bands developed near the center of circulation as the storm underwent an explosive intensification. Around 12:00 UTC, the storm reached severe tropical cyclone status when the sustained ten-minute wind speeds reached around 120 km / h and a small, irregularly shaped eye formed. However, the JTWC assessed the intensity of the cyclone to be much weaker until 0:00 UTC on February 14th. At that time, Pearl Harbor reported one-minute winds of 95 km / h, which corresponds to a weak category 3 cyclone on the Saffir-Simpson hurricane wind scale .

On February 14th at 12:00 UTC Nancy reached its greatest intensity with ten-minute wind speeds of 175 km / h and a central air pressure of 935 hPa. (The JTWC assumed peak intensity with sustained one-minute winds of 230 km / h.) Forward speed to the southeast and wind shear increased, which weakened Nancy. In the early hours of February 15, the cyclone passed directly over Manuae . The slowdown continued as a trough approached from the southwest. On February 16, the winds only reached gale force . Nancy turned southwest as a result of the Fujiwhara effect in interaction with cyclone Olaf further north.

Heavy wind shear associated with the cyclone Olaf outflow resulted in the full convection associated with Nancy relocating southwest on February 16. In the early 17th February transistierte Nancy into an extratropical cyclone. At this point the system came under the responsibility of the Tropical Cyclone Warning Center (TCWC) in Wellington . Shortly after, Nancy was absorbed into the greater circulation of Zyklon Olaf. However, the TCWC in Wellington was still observing Nancy as an independent system until 12:00 UTC on February 18.

Differences between the warning centers

The RSMC in Nadi uses ten-minute sustained wind speeds, while the Joint Typhoon Warning Center uses the one-minute wind speed-based criteria of the National Hurricane Center for its warnings primarily to United States facilities . The conversion factor between the two methods was set at 1.14. The greatest intensity was set by the RSMC Nadi for cyclone Nancy at 175 km / h at ten-minute wind speeds, which corresponds to 205 km / h at one-minute wind speeds. The peak intensity, which the JTWC determined at 230 km / h, would correspond to 205 km / h with a ten-minute observation.

Preparations

The cyclones Nancy (right) and Olaf (left) on February 14th

After the name was given on February 13, a storm warning was triggered for American Samoa . During the day, the storm warnings and strong wind warnings were extended to four states in the region, Samoa , Tuvalu , Tokelau and the Cook Islands. On February 14, cyclone warnings were given for the southern Cook Islands. In addition, a strong wind warning was issued for Niue . During the course of the day, this was extended to Wallis and Futuna . Hurricane warnings were issued for the southern Cook Islands on February 15 when Cyclone Nancy hit the archipelago .

Already startled by the effects of cyclone Meena just a week earlier, the inhabitants of the Cook Islands followed the warnings and took themselves to emergency shelters. Coastal areas where coastal protection has been damaged or destroyed by Meena received special attention from warning centers, which warned residents living nearby to seek emergency shelters. Tourists were also brought from hotels to one of the six emergency shelters on the islands. On the radio, the population was told all day to get to safety and the authorities had their personnel on standby. Eight emergency shelters have been set up on Rarotonga . The residents were evacuated from particularly low-lying areas because it was assumed that the swell would flood these areas. Schools on the islands were closed before the cyclone arrived until the storm passed. Many of the islands in the South Pacific were in a critical situation due to the rapid succession of four cyclones.

Effects and Consequences

Cyclones Nancy (below) and Olaf (above) 14 February 16

Cyclone Nancy caused significant damage in the Cook Islands. On Atiu the communication links were completely interrupted because the supply lines on the island were torn down. Peak gusts of 241 km / h were measured on the island. Four houses were destroyed and at least 80 trees were uprooted, making the streets impassable. The roofs of several houses were covered and the streets were covered with rubble and torn coconuts. Heavy rains fell on the islands. Numerous trees were uprooted on Manuae and Mauke by the storm . Four houses were destroyed there, three houses on Mitiaro could not withstand the storm. All roads on this island were blocked by fallen trees.

In Rarotonga , high waves damaged several bridges as a result of the cyclone. Schools, churches and restaurants were also affected by gusts of wind of up to 150 km / h. Cyclone Nancy destroyed fifteen temporary shelters that were built after Cyclone Meena blew through. The strongest winds were measured in the southern parts of the island chain, a gust of wind on Mangaia reached 259 km / h. In some places the seasonal harvest was completely destroyed by the cyclone.

As a result of the effects of four continuous cyclones, the Cook Islands asked for international help. A total of US $ 7.87 million (2005; adjusted for inflation, US $ 10,282,476) was made available. The Red Cross provided relief supplies such as blankets, tents and lanterns, the Pacific Forum provided aid in the form of food, fuel and logistical support worth $ 32,000, the government of the People's Republic of China gave $ 19,200 and the United Nations Development Program $ 32,000. The Australian Agency for International Development and New Zealand Aid raised a total of $ 862,570, including fuel, tents, and finance. The Australian government provided $ 128,000 worth of equipment and the French government dispatched military personnel with supplies and tents. The European Union made € 200,000 available.

Since Nancy caused significant damage in the Cook Islands, the name was removed from list A for the South Pacific and replaced by Nat . (Also Meena, Olaf, and Percy .) The three other cyclones impacting the region have been deleted and replaced by Mal , Olof, and Pita .

Individual evidence

  1. ↑ a b c d e f g h Tropical Cyclone Summery - 2004-2005 Season . (PDF (? KB)) RSMC NADI - Tropical Cyclone Center , archived from the original on December 12, 2007 ; accessed on September 21, 2014 (English, original website no longer available).
  2. ^ A b c d e Gary Padgett: Monthly Tropical Weather Summary for February 2005 ( English ) Typhoon 2000 . April 25, 2005. Retrieved June 24, 2009.
  3. ↑ a b c d JTWC Best Track for Cyclone 18P (Nancy) ( English ) Joint Typhoon Warning Center. 2006. Accessed on June 24, 2009.  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / metocph.nmci.navy.mil  
  4. ^ Joint Typhoon Warning Center Frequently Asked Questions (FAQ) . US Navy , archived from the original on July 27, 2009 ; accessed on September 21, 2014 (English, original website no longer available).
  5. ↑ a b c Section 2 Intensity Observation and Forecast Errors ( English ) United States Navy . 2009. Retrieved June 17, 2009.
  6. ↑ APCEDI ALERT 09F # 3, 2005: Cyclone Nancy Forms . In: AFAP Asia-Pacific Disaster Alerts . The Australian Foundation for the Peoples of Asia and the Pacific Ltd , February 13, 2005, archived from the original on December 5, 2008 ; accessed on January 18, 2016 (English, original website no longer available).
  7. ↑ Kevin Vang : Two Tropical Systems cause Warnings and Watches over 5 Countries . Australian Foundation for the Peoples of Asia and the Pacific (AFAP) , February 13, 2005, archived from the original on June 19, 2005 ; accessed on September 21, 2014 (English, original website no longer available).
  8. ↑ a b Kevin Vang : Dual Cyclones Nancy and Olaf Intensify; Cooks and Samoa in the Front Line . Australian Foundation for the Peoples of Asia and the Pacific (AFAP) , February 14, 2005, archived from the original on June 19, 2005 ; accessed on September 21, 2014 (English, original website no longer available).
  9. ↑ APCEDI ALERT 09F / 08F # 7, 2005: Dual Cyclones Nancy and Olaf Intensify; Warnings Now Cover 7 Island Nations . In: AFAP Asia-Pacific Disaster Alerts . The Australian Foundation for the Peoples of Asia and the Pacific Ltd , February 14, 2005, archived from the original September 5, 2008 ; accessed on January 18, 2016 (English, original website no longer available).
  10. ↑ Kevin Vang : Dual Cyclones Nancy and Olaf Still Intensifying; Critical Situation for Cooks, Samoa and American Samoa . Australian Foundation for the Peoples of Asia and the Pacific (AFAP) , February 15, 2005, archived from the original on June 19, 2005 ; accessed on September 21, 2014 (English, original website no longer available).
  11. ^ A b c Staff Writer: First assessments of damage from Cyclone Nancy . Radio New Zealand. February 15, 2005. Retrieved June 24, 2009.
  12. ↑ Kevin Vang : Dual Cyclones Nancy and Olaf Battering Southern Cooks, Somoa and American Samoa . Australian Foundation for the Peoples of Asia and the Pacific (AFAP) , February 15, 2005, archived from the original on February 18, 2005 ; accessed on September 21, 2014 (English, original website no longer available).
  13. ↑ APCEDI ALERT 09F / 08F # 10, 2005: Dual Cyclones Nancy and Olaf Continue to Pose Critical Situation for Cooks, Samoa and American Samoa . In: AFAP Asia-Pacific Disaster Alerts . The Australian Foundation for the Peoples of Asia and the Pacific Ltd , February 15, 2005, archived from the original September 5, 2008 ; accessed on January 18, 2016 (English, original website no longer available).
  14. ^ A b Staff Writer: Cyclone Nancy buffets Rarotonga ( English ) Radio New Zealand. February 15, 2005. Retrieved June 24, 2009.
  15. ↑ Samoa escapes worst cyclone ( English ) Xinhua News Agency. February 17, 2005. Archived from the original on October 24, 2012. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved June 24, 2009. @1@ 2Template: Webachiv / IABot / news.xinhuanet.com
  16. ↑ Twin cyclones hit South Pacific ( English ) United Press International. February 15, 2005. Retrieved June 24, 2009.
  17. ↑ a b c d Report and Recommendation of the President to the Board of Directors on a Proposed Loan and Technical Assistance Grant to the Cook Islands for the Cyclone Emergency Assistance Project . (PDF 627 kB) Asian Development Bank , June 2005, archived from the original on August 1, 2012 ; accessed on January 18, 2016 (English, original website no longer available).
  18. ^ A b c Kevin Vang : Dual Cyclones Nancy and Olaf Battering Southern Cooks, Somoa and American Samoa . Australian Foundation for the Peoples of Asia and the Pacific (AFAP) , February 16, 2005, archived from the original on June 19, 2005 ; accessed on September 21, 2014 (English, original website no longer available).
  19. ^ The South Pacific and southeast Indian Ocean tropical cyclone season 2004-05 ( English , PDF) Regional Office, Bureau of Meteorology, Brisbane, Australia. September 2007. Accessed in 2009-0624.
  20. ↑ a b Recovery Assistance to the Victims of Cyclones in the Cook Islands ( English , PDF; 138 kB) European Union . 2005. Retrieved June 24, 2009.
  21. ^ Tropical Cyclone Naming . World Meteorological Organization. 2008. Retrieved June 22, 2009.

Remarks

  1. ↑ The sustained wind speeds reported by the Regional Specialized Meteorological Center of the Fiji Meteorological Service in Nadi are based on the ten-minute standard and apply the scale of the Australian Bureau of Meteorology .