Typhoon Ketsana (Ondoy)

Ketsana prior to peak intensity on September 28
Meteorological history
Formed	September 24, 2009
Dissipated	September 30, 2009
Typhoon
10-minute sustained (JMA)
Highest winds	130 km/h (80 mph)
Lowest pressure	960hPa (mbar); 28.35 inHg
Category 2-equivalent typhoon
1-minute sustained (SSHWS/JTWC)
Highest winds	165 km/h (105 mph)
Lowest pressure	955hPa (mbar); 28.20 inHg
Overall effects
Fatalities	710 direct
Missing	439
Damage	$1.15 billion (2009USD)
Areas affected	Philippines, China,Vietnam,Laos,Cambodia,Thailand
IBTrACS
Part of the2009 Pacific typhoon season

Typhoon Ketsana, namedOndoy byPAGASA was a catastrophictropical cyclone that caused extensive damages acrossSoutheast Asia, particularly in thePhilippines andVietnam. It is both the second deadliest and costliest typhoon of the2009 Pacific typhoon season, with at least$1.15 billion in damages and 710 fatalities, trailing behindMorakot with 789 deaths and damages worth$6.2 billion.

The sixteenth tropical storm and eighth typhoon of the season, Ketsana formed early about 860 km (530 mi) northwest ofPalau on September 23, 2009. Initially, it was downgraded to a low pressure area by theJapan Meteorological Agency (JMA), but after drifting through favorable conditions, it intensified the next day and was categorized as a tropical depression by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), and was given the nameOndoy after entering thePhilippine Area of Responsibility. TheJoint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert on the depression. It was then upgraded to a tropical depression by the JMA later that morning before the JTWC followed suit early on September 25, designating the depression as 17W. Soon, the depression strengthened into atropical storm, and was given the nameKetsana by the JMA. Shortly after, it made landfall over the Philippines, and as it moved into theSouth China Sea, the storm intensified while moving towards the west. It peaked as a Category 2-equivalent typhoon before ultimately making landfall on Vietnam at peak intensity on September 29, dissipating on the next day.

While Ketsana made landfall north ofMetro Manila as a tropical storm, it enhanced the southwest monsoon, bringing record-breaking rainfall and flooding across the Philippines' capital. At least 464 deaths^[a] and $237 million (₱11.1 billion) were attributed to the typhoon, making it the most devastating tropical cyclone to hit Metro Manila,^[8] surpassingTyphoon Patsy (Yoling) in1970. Flood water levels also reached a record 20 feet (6.1 m) in rural areas. In response to this,PresidentGloria Macapagal Arroyo declared a "state of calamity" encompassing most of Luzon after at least 86 people were initially reported dead inlandslides and other incidents.^[9] Recovery efforts from the storm's onslaught would later be hampered byTyphoon Parma, which made landfall in the Philippines roughly a week after Ketsana.

On September 23, 2009, theJapan Meteorological Agency (JMA), reported that a seasonal tropical depression had formed about 860 km (530 mi) to the northwest ofPalau.^[10] TheJoint Typhoon Warning Center (JTWC) then reported later that day that the depression had a developinglow-level circulation center and was in a favorable environment with low vertical wind shear.^[11] The JMA then reported that the depression had weakened into anarea of low pressure.^[12] However, early the next day, as deep convection started to consolidate around the low-level circulation center, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) reported that the low-pressure area had become a tropical depression and assigned it a local name of Ondoy.^[13][14] Later that morning, the JTWC issued aTropical Cyclone Formation Alert as central convection had continued to organize around a consolidating elongated but exposed low-level circulation center.^[15] The JMA then re-upgraded Ondoy to a tropical depression later that morning before the JTWC followed suit early on September 25, designating it as Tropical Depression 17W when it was located about 400 nm east of Manila in the Philippines.^[16][17] At this stage, the system was moving along the southern side of the subtropical ridge and had good poleward outflow into atropical upper tropospheric trough (TUTT) cell.^[17]

Throughout September 25 the intensification of Ondoy was hampered by the system moving into an area of moderate verticalwind shear and by an upper-level trough of pressure that was moving over the system.^[18] But later that day the JTWC upgraded it to a tropical storm despite its low level circulation center being partially exposed.^[19] The JMA followed suit early the next day, assigning the international name of Ketsana and the international designation of 0916 to the storm.^[20] PAGASA then reported that Ketsana had made landfall on Northern Luzon near the boundary of the Philippine provinces ofAurora andQuezon. As a result of making landfall, its low-level circulation center had become fully exposed, but as the storm moved into theSouth China Sea, it dramatically deepened and expanded while moving west and was upgraded to a severe tropical storm by the JMA early on September 27.

During September 27, Ketsana gradually developed further and was upgraded to a typhoon by the JTWC and the JMA early the next day, as multiple convective bands were continuing to consolidate more tightly around the low-level circulation center, leading to the formation of a disorganized eye. Typhoon Ketsena then intensified quickly under favorable conditions, reaching peak windspeeds later that day of 165 km/h (103 mph)(1-min winds) and 140 km/h (87 mph)(10-min winds) which made it a Category 2 typhoon on theSaffir–Simpson scale. Ketsana then made a second landfall onQuảng Nam inVietnam, at 0600 UTC on September 29 at its peak intensity. It then rapidly weakened into a Severe Tropical Storm, with the JTWC issuing its last advisory later that day; however, the JMA continued to monitor Ketsana as a Severe Tropical Storm until later that day, when it downgraded it to a Tropical Storm before further downgrading it to a Tropical Depression early the next day when the center of the depression was located overLaos. The JMA monitored the storm as a weak tropical depression until late on September 30, when it released its final advisory.

On September 24, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) placed the provinces ofAurora, northernQuezon,Camarines Norte,Camarines Sur, andCatanduanes underPublic Storm Warning Signal (PSWS) No. 1, which meant that winds of 30–60 km/h (19–37 mph) were expected to affect those areas within 36 hours. PAGASA raised PSWS No. 2 for the provinces ofCatanduanes,Camarines Norte andCamarines Sur, andPolillo Island inQuezon.^[21] On September 28, PAGASA lifted all public storm signals in the country as Ketsana left thePhilippine Area of Responsibility (PAR) the same day.^[22] After thefloods struck, some were critical of the government's failure to predict the scale of the disaster or to lessen the damage it caused.^[6]

Late on September 27, both theHong Kong Observatory and theMacao Meteorological and Geophysical Bureau placedHong Kong andMacau under the Standby Signal No.1.^[23][24] The Bureau then considered hoisting theStrong Wind Signal 3, but decided it was not needed for Hong Kong, while Macau hoisted it early the next day. These warnings were kept in force until later that day when all warnings were lowered.^[23] On September 29 it was announced that parts of southern China would be placed under an orange warning with certain regional meteorological bureaus entering a level 3 emergency response.

On September 27, the Vietnam National Center for Hydro-Meteorological Forecasting^[25] issued a public storm warning signal named "Number 9." The Vietnamese government evacuated some 170,000 people. The government instructed residents to secure their homes with fortified hard wood and sandbag roofs. Also, authorities mobilized several thousand military personnel and police to help residents evacuate from the typhoon's path. Fishing vessels were called to return to their ports.^[26] This caused thousands of crops to fail.

Ketsana caused widespreadflash flooding in the cities ofManila,Caloocan,Marikina,Malabon,Muntinlupa,Quezon,Makati,Pasay,Pasig,Taguig,Valenzuela, andSan Juan. Flooding also occurred in the nearby provinces ofBulacan,Rizal,Laguna, and otherCalabarzon areas. Major roads were rendered impassable because of huge flood currents and clogged cars.^[28] Air flights were canceled because of heavy rains.

Earlier,power interruptions were reported inCamarines Norte, and minorlandslides occurred inCamarines Sur.^[28]

EDSA was closed because of heavy flooding.Defense Secretary andNational Disaster Risk Reduction and Management Council (NDCC) chairmanGilbert Teodoro asked theDOTC to keepMRT andLRT lines operational to accommodate stranded passengers.^[29]

On the afternoon of September 26, Gilbert Teodoro declared an overallstate of calamity inMetro Manila and the nearby 25 provinces in Luzon hit by the typhoon, allowing officials to utilize emergency funds for relief and rescue. Army troops, police, and civilian volunteers were deployed to rescue victims.^[30] ThePhilippine National Red Cross and thePhilippine Coast Guard dispatched teams to rescue stranded and trapped people.^[31] At that time, the average height of flooding was from two feet to waist high, and in some areas above six feet.^[32]EvenMalacañang Palace was opened to those who were in need.Thelandslides and severeflooding left at least 246 people dead and 38 others missing.^[6][27] Public and private roads were clogged by vehicles stuck in floodwater.^[6] Thousands of motorists and more than 500 passengers were stranded at theNorth Luzon Expressway (NLEx). Distress telephone calls and emails from thousands of Metro Manila residents and their worried relatives flooded television and radio stations overnight as most of the power supply, communication, and water supply were lost.^[33] Ketsana also causedNinoy Aquino International Airport (NAIA) to close for almost a day.^[34]

The economic region ofMetro Manila and many adjoining provinces incurred damages to bothinfrastructure andagriculture. As of September 28, 2009, total damages from Ketsana were estimated at $100 million.^[1][2][6]Internet cafés, entertainment plazas, banks, food stores, building agencies, and stores were soaked with water and mud.^[6][35] Many people were warned ofleptospirosis.

Flooding near theSM City Marikina

Flooding atRiverbanks Center

Marikina, part of Metro Manila, was the most devastated region in the Philippines: almost all of the city's area was submerged in water up to ten feet deep and tons of knee-deep mud. During the typhoon, theMarikina River broke its banks and transformed streets into rivers.^[36] Marikina residential areas, particularly Provident Village, were badly affected by flooding; at least eight people were found dead.^[37] Marikina itself recorded 78 deaths, the highest among Metro Manila cities.^[38]

At the height of the flooding, around 100,000 liters of bunker oil from the paper manufacturing firm Noah's Paper Mill in Marikina spilled. Most of the oil battered the city'sbarangays, and a relatively small amount was washed into the basement of theSM City Marikina shopping mall. The spill later complicated rescue efforts in the city.^[39] Over two days starting on September 29, theNational Power Corporation Flood Forecasting and Warning System released 500 cubic meters per second of stored water from theAngat Dam inBulacan. The dam had accumulated 100 cubic meters per second when Ketsana hit the province.^[40]Mandaluyong also recorded more than 6 feet (1.8 m) of flooding, especially in Gen. Kalentong St., where flooding was more than 10 feet (3.0 m) deep,^[41] badly affectingthe local campus of Arellano University. The street recorded the highest flooding outside the Marikina area.

InMindanao, several towns inCotabato City and nearbySultan Kudarat municipalities were submerged. The closing of the national highway in Bulalo, Cotabato City led to the isolation of connecting towns for several days.^[42]

A weather station onLý Sơn Island near the coast of Vietnam recorded sustained winds of 115 km/h (72 mph), with gusts up to 155 km/h (96 mph). On the mainland of Vietnam, only one weather station in Da Nang recorded sustained tropical storm-force winds, with sustained winds of 79 km/h (49 mph) and gusts of 108 km/h (67 mph). Other stations reported sustained winds below tropical storm-force level.^[43]

The rainfall in the area from Thua Thien-Hue to Quang Ngai from September 28 to September 30 ranged from 400 mm to 600 mm. Some places recorded more than 600 mm, such asNam Đông (Thừa Thiên Huế) with 884 mm andTrà Bồng (Quảng Ngãi) with 1,948 mm.^[43]

Airports, schools, communications, and electricity in the affected area were shut down. Strong winds also destroyed parts of the north–south high voltage powerline, the backbone of Vietnam's electricity grid. In total the typhoon killed 179 people in Vietnam, 23 during the first hours after landfall; 8 people were missing and 1,140 injured.^{[51][26][52][53][54]} Total economic losses caused by Ketsana were 16.07 trillionVND (US$896.1 million).^{[n 2][51][55]}

The weakening typhoon struck northeasternCambodia as one of the most severe storms ever to lash the country, with the worst damage inKampong Thom Province in central Cambodia. Death tolls reached 43 people.^[56] More than 66,000 families were forced from their homes by floodwaters.

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There was major flooding in the southern and central provinces ofLaos, and much of the country experienced heavy rain and light flooding. Water was up to knee height in the province ofSaravane, and at least 26 people died. The cities ofSavannakhet andPakse were worst affected since they were directly on the pathway of the typhoon and directly on theMekong River. In theSi Phan Don area inChampassak Province, some people took refugee on the roofs of their houses. The floods devastated rice fields and homes.Attapeu was the worst hit province, with nearly 90% of the province affected.

As the weakening Ketsana moved through the country, widespread heavy rainfall and flash flooding were reported in 40 provinces.^[57] The heavy rainfall also helped to fill up natural reservoirs within the country.^[57] The depression partially damaged 4680 houses and destroyed 44, as well as 820,000 acres (330,000 ha) of agricultural land.^[57] Ketsana also injured one person and killed two before moving out of the country as an area of low pressure and dissipating on October 3 over theAndaman Sea.^[57] Total damages were estimated at just over$20,000,000.^[57] Three dams in Chai-ya-poom were damaged by the heavy rainfall, while inPattaya nine boats were sunk waves reported to be over two metres high.^[58]

ThePhilippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) documented a record-high amount of rainfall in 24 hours at 455 millimetres (17.9 in). They also reported that Ketsana's rainfall was recorded from 8 am PST/ 0000 (UTC) of Saturday (September 26) to 8 am PST/ 0000 (UTC) of Sunday (September 27). The amount of rainfall recorded for six hours, which was 341.3 millimetres (13.44 in), was comparable to the 24-hour rainfall in 1967.^[59] The damage to property was estimated to beP6 billion, including P4.1 billion in damage to infrastructure, P1.9 billion in damage to schools, and P882.525 million in damage to agriculture.^[60][61]

According to theBureau of Agricultural Statistics of theDepartment of Agriculture (DA), an estimated 126,721 hectares of rice-farming land were destroyed, which would affect almost 3% of the country's annual expected rice production. Added to this, Ketsana devastated some 1,374 hectares of corn plantations.^[62]

Some 48 hours after Ketsana struck Metro Manila, the Philippine government appealed to the international community and theUnited Nations for help.^[63] Various United Nations agencies, theUnited States, thePeople's Republic of China, andJapan provided emergency assistance to typhoon victims in the Philippines.^[64] The United States donated $50,000, while China and Japan gave $10,000 and $20,000 respectively.Australia providedA$1 million, andThailand also provided humanitarian services.^[65][66]Germany donated €500,000,^[67] andTaiwan donated $50,000.^[68] The United States also deployedMarines to help rescue victims in theCainta andPasig areas, as well as for search and retrieval operations for dead bodies.^[69][70][71]Special Forces Operators and other U.S. service members attached toJoint Special Operations Task Force Philippines also assisted in aid efforts.^[72] An additional 3,000 U.S. troops were expected to arrive to assist in relief efforts.^[73] U.S. Nonprofit international disaster relief organizationAmeriCares shipped $3.2 million of medical aid for Ketsana survivors.^[74] AnIsraeli search and rescue party, doctors, nurses, and paramedics were sent to the Philippines.^[75]

In the Philippines, the National Disaster Coordinating Council (NDCC) headed the rescue and relief operations for the citizens affected by Ketsana's flooding. There was also a counterpart private-sector effort among companies andNGOs to provide and coordinate relief activities in various areas.

ThePhilippine Army deployed about 1,000 soldiers in Metro Manila and surrounding provinces to help in operations.^[76] ThePhilippine Red Cross and thePhilippine Coast Guard also deployed teams in rubber boats to rescue people stranded in their homes.^[6][77] On the Internet, citizens turned to social networks likeTwitter,Facebook,Plurk, andMultiply to share news updates and forward cries for help from people trapped in the floods.Google Maps was used to pinpoint the locations of stranded people, while various blogs and websites shared information on donating money and in-kind goods.^[78] Donations arrived from all over the world and were sorely needed.

After Typhoon Ketsana andTyphoon Parma, the government ofJapan gave the Philippines a P1.7-billion (3.350 billion yen) grant to improve the country's weather monitoring and information dissemination system.^[79][80]

•  Australia: A$11,000,000
• Canada: C$5,100,000, aid packages, water purification systems^[81]
  • Canadian federal government: C$5,000,000, priority in visa applications for both temporary and permanent residence^[82][83]
  • Province ofManitoba: C$100,000^[84]
• China: $140,000^[85]
•  Japan: $20,000
•  European Union: €2,000,000^[86]
•  Germany: €500,000
•  Israel: medical teams
• Malaysia: 20 tonnes of food aid^[87]
•  New Zealand: NZ$25,000^[88]
• Singapore: $20,000 and 3,200 water purification sets
• South Korea: aid workers^[89]
• Taiwan: $50,000
• Thailand: humanitarian services
•  United States: $3,250,000
  • U.S. government: $50,000
  • U.S. military:USS Tortuga (LSD-46) andUSS Harpers Ferry (LSD-49), 3rd Marine Expeditionary Force plus 20 USMC personnel, a helicopter and four Zodiac inflatable boats.^[90]
  • AmeriCares: $3.2 million

Vietnamese officials and media reported that Chinese naval forces mistreated Vietnamese fishermen who tried to take shelter from the typhoon in the disputedParacel Islands. The Chinese Navy allegedly fired on Vietnamese fishing boats when they tried to take shelter at Tru Cau island to escape Typhoon Ketsana and after being allowed to stay on the island for several days, they were robbed and beaten by Chinese forces before leaving.^[91] Vietnam and China have an agreement that fishermen from either country can ride out storms in the other's territory.

Nguyen Viet Thang, chairman of the Vietnam Fishery Association, said his organization was preparing an official protest to China over the incidents. Colonel Bui Phu Phu, vice chief of the border guard forces of the fishermen's home province ofQuảng Ngãi, confirmed the accusations and said the Ministry of Foreign Affairs should send a protest to China.^[92]

An official at the Chinese embassy in Hanoi said China had no comment on the accusations.

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Due to the damage and deaths caused by the storm, the nameKetsana was laterretired by the committee. The nameChampi was selected to replaceKetsana on the Western Pacific basin name lists beginning in 2011. It was first used in the2015 Pacific typhoon season.

In June 2012, PAGASAretired the nameOndoy from their naming lists and replaced it withOdette. It was first used in the2013 Pacific typhoon season.

WhenPresidentBenigno Aquino III took office in June 2010, PAGASA Chief AdministratorPrisco Nilo was fired and removed from his post on August 6.^[93] The agency accused Nilo of having a supposedly fool-proof forecast of Typhoon Ketsana as the typhoon struck overMetro Manila. Aquino adds lack of disaster preparedness and slow installation ofDoppler weather radar and other equipment, and slow voluntary response that left the agency unmodernized.

Nilo left PAGASA after Graciano Yumul, Jr., took Nilo's vacant seat. This similar accusation also happened on the aftermath ofTyphoon Conson (Basyang) in July 2010. Nilo was inAustralia for his new post as weather forecaster of theBureau of Meteorology (BOM).

• List of Philippine typhoons (2000–present)
• Typhoons in Vietnam

Wikimedia Commons has media related toTyphoon Ketsana (2009).

• RSMC Tokyo – Typhoon Center
  • Best Track Data of Typhoon Ketsana (0916)(in Japanese)
  • Best Track Data (Graphics) of Typhoon Ketsana (0916)
  • Best Track Data (Text)
• JTWC Best Track DataArchived October 10, 2012, at theWayback Machine of Typhoon 17W (Ketsana)
• 17W.KETSANAArchived January 29, 2016, at theWayback Machine from the U.S. Naval Research Laboratory
• ReliefWeb'smain page for this event.
• TV Patrol World's news report on the typhoon onYouTube - video fromABS-CBN

• 2009 Pacific typhoon season
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• 2009 in Cambodia
• 2009 in Thailand
• 2009 disasters in the Philippines
• September 2009 in Asia
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• Typhoons in China
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• Typhoons in Cambodia
• Typhoons in Thailand
• History of Metro Manila
• Tropical cyclones in 2009

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