View source for Cyclone Olaf

{{Short description|Category 5 South Pacific cyclone in 2005}}
{{Infobox weather event
| name = Severe Tropical Cyclone Olaf
| image = Olaf 2005-02-16 0110Z (Gallery).jpg
| caption = Cyclone Olaf near peak intensity on February 16
| formed = February 10, 2005
| extratropical = February 20, 2005
| dissipated = February 25, 2005
}}{{Infobox weather event/FMS
| winds = 115
| pressure = 915
}}{{Infobox weather event/JTWC
| winds = 145
| pressure = 892
}}{{Infobox weather event/Effects
| fatalities = None
| missing = 2
| damage = 10000000
| areas = [[American Samoa]], [[Samoa]], [[Cook Islands]]
}}{{Infobox weather event/Footer
| season = [[2004–05 South Pacific cyclone season]]
}}

'''Severe Tropical Cyclone Olaf''' was the sixth cyclone to form in the Southwest Pacific Ocean during the [[2004–05 South Pacific cyclone season]]. Olaf was also one of three simultaneous cyclones to form during the 2004–05 season, forming 21&nbsp;hours after Cyclone Nancy formed to the east. A powerful [[Saffir–Simpson Hurricane Scale|Category 5]] cyclone, Olaf stuck [[American Samoa]] causing heavy damage although exact estimates are unknown. Despite the damage, there were no reported deaths or injuries from the cyclone. Olaf was third South Pacific cyclone to hit the [[Cook Islands]] during the 2004–05 season (the other two being Meena and Nancy), and [[Cyclone Percy]] would later affect the already devastated archipelago less than 2 weeks later.

==Meteorological history==
{{storm path|Olaf 2005 track.png}}
Towards the middle of February 2005, a monsoonal trough of low pressure developed near the island nation of [[Tuvalu]] and extended eastwards to the north of the [[Samoan Islands]].<ref name="ATCR">{{cite report|archive-url=https://web.archive.org/web/20090225212738/http://www.met.gov.fj/documents/TC_Seasonal_Summary_04-051190690498.pdf|publisher=Fiji Meteorological Service|access-date=December 29, 2020|title=Tropical Cyclo.ne Summary 2004&nbsp;– 2005 Season |url=http://www.pacificdisaster.net/pdnadmin/data/original/TC_Seasonal_Summary_2004-2005.pdf |archive-date=February 25, 2009|url-status=dead}}</ref> During February 10, this area of low pressure spawned two systems, which were classified as the eight and ninth tropical disturbances of the [[2004-05 South Pacific cyclone season|2004-05 season]] by the [[Fiji Meteorological Service]] (FMS).<ref name="ATCR"/> The first of these tropical disturbances was classified as 09F, while it was located about {{convert|330|km|mi|round=5|abbr=on}} to the northeast of Apia, Samoa and later developed into [[Cyclone Nancy|Severe Tropical Cyclone Nancy]].<ref name="ATCR"/> The second of these disturbances was 08F which was classified as a tropical disturbance while it was located about {{convert|650|km|mi|round=5|abbr=on}} to the northeast of Nadi, Fiji.<ref name="ATCR"/>

A [[tropical wave]] formed on February 10. The tropical wave, then spawned two areas of low pressure, one of which became Tropical Depression 08F. At 1300 UTC, the tropical depression was located 490&nbsp;miles north west of [[Apia]]. By 1500, the depression organized into a tropical storm with 40&nbsp;mph wind and was named Olaf. At the time of formation, the tropical storm was nearly stationary. The low [[wind shear]] and warm water temperatures allowed Olaf to undergo rapid intensification. In a 12‑hour period, Olaf quickly became a [[Saffir–Simpson Hurricane Scale|Category 1]] cyclone with {{convert|80|mph|km/h|abbr=on}} winds in a 10-minute average speed. On February 15, the barometric pressure fell to 930&nbsp;mbar as Olaf reached [[Saffir–Simpson Hurricane Scale|Category 4]] status. After reaching [[Saffir–Simpson Hurricane Scale|Category 4]] status, Olaf then moved on a south-southeasterly course at {{convert|7|mph|km/h|abbr=on}}.<ref name="mgt">[http://australiasevereweather.com/cyclones/2005/summ0502.htm Olaf Report]</ref>

Cyclone Olaf then tuned east and moving {{convert|100|mi|km}} east of [[Western Samoa]]. On February 16, satellite imagery depicted a well-defined eye as Olaf strengthened into a [[Saffir–Simpson Hurricane Scale|Category 5]] cyclone. Olaf reached a peak intensity of 165&nbsp;mph with a barometric pressure of 915&nbsp;millibars. It is possible Olaf could have a lower pressure but official track reports have Olaf at 915&nbsp;mbar. At the time of peak intensity, the center of the storm was only {{convert|70|mi|km}} northeast of [[American Samoa]] and {{convert|90|mi|km}} northwest of [[Pago Pago]]. At the same time, Cyclone Olaf underwent a minor [[Fujiwhara effect]] with Cyclone Nancy before resuming its southeasterly course. Moving at {{convert|10|mph|km/h|abbr=on}}, the cyclone maintained [[Saffir–Simpson Hurricane Scale|Category 5]] status as the eye passed 15&nbsp;miles east of [[Ta'u]], [[American Samoa]]. During that time, a weather station reported a 931 barometric pressure reading.<ref name="mgt"/>

On February 18, an approaching upper-level trough to the south, and strong [[wind shear]] caused Olaf to weaken as the storm rapidly moved southeastward. As Olaf moved into the [[New Zealand]] area of responsibility, the main circulation separated from the center and Olaf quickly became extratropical 18&nbsp;hours later. The extratropical remnants of Olaf, quickly re-intensified into a powerful [[extratropical storm]] on February 23. The extratropical storm persisted for two days before dissipating near [[Pitcairn Island]]<ref name="mgt"/>

==Preparations==
[[Image:Nancy and Olaf 14 feb 2005.jpg|right|thumb|Tropical Cyclones Nancy (right) and Olaf (left) on February 14]]
Forecasts predicted Olaf to move near and over Samoa and American Samoa in 24–48&nbsp;hours and hitting the southern [[Cook Islands]] as a [[Saffir–Simpson Hurricane Scale|Category 4]] cyclone.<ref>[http://www.afap.org/apcedi/2005/02/apcedi-alert-09f08f-8-2005-dual.html AFAP Warning 1] {{webarchive|url=https://web.archive.org/web/20060215073008/http://www.afap.org/apcedi/2005/02/apcedi-alert-09f08f-8-2005-dual.html |date=2006-02-15 }}</ref> In American Samoa, schools and businesses were closed and warnings were broadcasting over television and radio. Forecasters predicted that Olaf will bring [[storm surge]] and inland flooding and strong winds. In [[Niue]], the cyclone was carefully monitored by forecasters, fearing a repeat of the destruction wrought by [[Cyclone Heta]] a year ago. [[French Polynesia]] was also under a cyclone warning. Forecasters further issued Watches and warnings for the rest of the [[Cook Islands]].<ref>[http://www.afap.org/apcedi/2005/02/apcedi-alert-09f08f-12-2005-dual.html AFAP Warning 2] {{webarchive|url=https://web.archive.org/web/20060215073107/http://www.afap.org/apcedi/2005/02/apcedi-alert-09f08f-12-2005-dual.html |date=2006-02-15 }}</ref>

The next day, Olaf diverted course forcing authorities to order evacuations. In [[Tutuila]], 70 emergency shelters were opened and 1,000&nbsp;people evacuated low-lying areas. The approach of the cyclone, shut down the local airport, cancelling numerous flights. In [[Tau]], most of the residences evacuated to storm shelters built on higher ground. The evaluation in the Manu'a group islands, totaled up to 2,000.<ref>[http://www.afap.org/apcedi/2005/02/apcedi-alert-09f08f-15-2005-super.html AFAP Warning 3] {{webarchive|url=https://web.archive.org/web/20060215073125/http://www.afap.org/apcedi/2005/02/apcedi-alert-09f08f-15-2005-super.html |date=2006-02-15 }}</ref>

==Impact==
A destructive [[cyclone]], Olaf caused severe damage in both Samoa and American Samoa. Because of well executed warnings and evacuations, there were no deaths. However, 2&nbsp;people were reported missing and assumed dead, when their boat sank during the storm.

===Samoa and American Samoa===
[[Image:Landslide caused by Olaf.jpg|left|thumb|Landslide damage from Olaf.]]
Although the eye of Olaf never made landfall, several weather stations reported sustained winds of {{convert|75|–|125|mph|km/h|abbr=on}}. The winds damaged powerlines and closed an airport. Olaf also produced [[storm surge]] damage along the coast.<ref name="mgt"/> Offshore, fishing fleet was caught off guard by the storm. One of the boats, sank {{convert|150|mi|km}} off the coast of Samoa, however the crew was rescued.<ref>{{cite web |title=Cyclone Olaf slams into Samoa |date=2005-02-17 |website=[[The Sydney Morning Herald]] |archive-url=https://web.archive.org/web/20130217204344/https://www.smh.com.au/news/World/Cyclone-Olaf-slams-into-Samoa/2005/02/17/1108609334517.html |archive-date=2013-02-17 |url-status=live |url=http://www.smh.com.au/news/World/Cyclone-Olaf-slams-into-Samoa/2005/02/17/1108609334517.html}}</ref> 21 other fishermen were also rescued.<ref name="mgt"/> Olaf then brushed past the American Samoa, bringing {{convert|125|mph|km/h|abbr=on}} winds. Because of Olaf strength, there was severe damage across American Samoa. In the [[Manua Islands]], the storm destroyed several seaside homes, ruined crops and left thousands without power. In [[Tau]], 80–90&nbsp;percent of the infrastructure was destroyed by the storm.<ref name="mgt"/> Offshore, three people were rescued after their boat sank near [[Pago Pago]].<ref>[https://www.nbcnews.com/id/wbna6976130 nbcnews.com]</ref>

===Cook Islands===
Olaf then struck the [[Cook Islands]] which were already reeling form the impact of Cyclones Meena and Nancy earlier. In [[Rarotonga]], Olaf skirted the western side of the island. That placed the island in the strongest part of the storm, which resulted in extensive damage to homes and businesses. According to press reports, nearly 30–40 percent of the population was left without electricity and 60% of the structures sustained damage.<ref name="mgt"/>

==Aftermath==
Olaf damaged several water stations in the Manua Islands causing a water shortage. Because of the damage, President [[George W. Bush]] declared those islands disaster areas. The declaration allowed residents and local governments in the American Samoa to receive federal aid. The [[Federal Emergency Management Agency]] provided much aid to the residents of the American Samoa.<ref>[http://www.fema.gov/news/eventcounties.fema?id=4068 FEMA Disaster Declaration] {{webarchive|url=https://web.archive.org/web/20070911133002/http://www.fema.gov/news/eventcounties.fema?id=4068 |date=2007-09-11 }}</ref> The [[Initial Response Resources]] were sent to the American Samoa and its surrounding islands and was distributed by the [[United States Coast Guard]] and the government of the American Samoa on February 21, 2005.<ref>[http://www.doi.gov/oia/Stories/2005/tropical_cyclon_Olaf.htm DOI report on the Olaf] {{webarchive|url=https://web.archive.org/web/20070404091515/http://www.doi.gov/oia/Stories/2005/tropical_cyclon_Olaf.htm |date=2007-04-04 }}</ref> Despite the devastation in the Manua Islands, it could have been worse if Olaf hit American Samoa directly.<ref name="mgt"/>  In the Cook Islands, the Australian and [[New Zealand]] governments provided over A$30,000 (2005) in relief assistance.<ref>[http://www.reliefweb.int/rw/RWB.NSF/db900SID/VBOL-6A2CG5?OpenDocument Cyclone Olaf Update February 28, 2005]</ref> On February 22, 2005, the Government of New Zealand, provided materials and workmen to help with the cleanup effort. The French government and the [[United Nations]] also assisted in the relief effort by sending soldiers from [[Tahiti]] and providing more aid to the stricken residents.<ref>{{Cite web |url=http://www.cinews.co.ck/OLAF.htm#7 |title=Cinews report on Olaf |access-date=2007-04-30 |archive-url=https://web.archive.org/web/20071008050943/http://www.cinews.co.ck/OLAF.htm#7 |archive-date=2007-10-08 |url-status=dead }}</ref>

Because of the extensive damage in Samoa and the Cook Islands, Olaf was retired in May of 2006, and was replaced with Osai.

==See also==
{{Portal|Tropical cyclones}}
*[[Tropical Storm Olaf|Other storms of the same name]]
*[[List of retired South Pacific cyclone names]]

==References==
{{Reflist}}

==External links==
{{Commons category|Cyclone Olaf}}
{{SPAC EL's}}

{{2004–05 South Pacific cyclone season buttons}}
{{Category 5 South Pacific severe tropical cyclones}}
{{Retired South Pacific cyclones}}

{{DEFAULTSORT:Olaf (2005)}}
[[Category:2004–05 South Pacific cyclone season]]
[[Category:Tropical cyclones in American Samoa]]
[[Category:Tropical cyclones in the Cook Islands]]
[[Category:Retired South Pacific cyclones]]
[[Category:Category 5 South Pacific cyclones]]
[[Category:2005 in American Samoa]]
[[Category:2005 in the Cook Islands]]
[[Category:Tropical cyclones in 2005|Olaf]]