Tropical Storm Washi
|Severe tropical storm (JMA)|
|tropical storm (SSHS)|
|Severe Tropical Storm Washi approaching Mindanao on December 16, 2011|
|Formed||December 13, 2011|
|Dissipated||December 19, 2011|
|Highest winds||10-minute sustained:
95 km/h (60 mph)
95 km/h (60 mph)
|Lowest pressure||992 mbar (hPa); 29.29 inHg|
|Damage||$48.4 million (2012 USD)|
|Areas affected||Micronesia, Palau, Philippines|
|Part of the 2011 Pacific typhoon season|
Severe Tropical Storm Washi (international designation: 1121, JTWC designation: 27W, PAGASA name: Sendong) was a late-season tropical cyclone that caused catastrophic damage in the Philippines in late 2011. Washi, which means Aquila in Japanese, made landfall over Mindanao, a major island in the Philippines, on December 16. Washi weakened slightly after passing Mindanao, but regained strength in the Sulu Sea, and made landfall again over Palawan on December 17.
In the Philippines, catastrophic flash flooding triggered by Washi resulted in at least 1,268 fatalities. In post-analysis, the Japan Meteorological Agency (JMA) upgraded Washi from a tropical storm to a severe tropical storm.
Meteorological history 
On December 12, the Joint Typhoon Warning Center (JTWC) noted that a developing area of low pressure had persisted about 945 km (585 mi) south-southeast of Guam. Situated along the southern edge of a subtropical ridge, the system tracked steadily westward towards the Philippines. Located within a region of good diffluence and moderate wind shear, deep convection was able to maintain itself over the circulation. Development of banding features and improvement of outflow indicated strengthening was likely. Further development over the following day prompted the JTWC to issue a Tropical Cyclone Formation Alert early on December 13. Less than six hours later, both the JTWC and the Japan Meteorological Agency (JMA) classified the system as a tropical depression, with the former assigning the identifier 27W. Maintaining a westward track, the depression was forecast to intensify slowly over the following three days. For much of December 13, a slight increase in shear displaced thunderstorm activity from the center of the depression, delaying intensification. By December 14, convection redeveloped over the low and the JTWC subsequently assessed the system to have attained tropical storm status.
Early on December 15, the system crossed west of 135°E and entered the Philippine Atmospheric, Geophysical and Astronomical Services Administration's (PAGASA) area of responsibility. Upon doing so, PAGASA began issuing advisories and assigned the cyclone with the local name Sendong. Shortly thereafter, the storm passed close to or over Palau. By 0600 UTC, the JMA upgraded the system to tropical storm status, at which time they assigned it with the name Washi. Maintaining a rapid westward track, Washi slowly became more organized, with low-level inflow improving during the latter part of December 15. On December 16, Washi reached its peak strength as a severe tropical storm and made its first landfall along the east coast of Mindanao.
After passing Mindanao, Washi weakened due to land interaction, but the storm quickly regained its strength, in the Sulu Sea. Late on December 17, Washi crossed Palawan and arrived in the South China Sea, and the system moved out of the PAR on December 18. Washi weakened to a tropical depression and dissipated on December 19, because of cool, dry air, in association with the Northeast Monsoon.
Severe Tropical Storm Washi brought 10 hours of torrential rains that triggered disastrous flash flooding over Mindanao, an area that rarely experiences tropical cyclones. More than 200 mm (7.9 in) of rain was reported in places where rivers were already swollen. During the overnight hours, hundreds of people were killed as flood waters and landslides destroyed homes along mountain sides. In some locations, flood waters rose by 3.3 m (11 ft) in less than an hour. Residents impacted by these flood waters were forced to seek refuge on their roofs amidst 90 km/h (55 mph) winds. The mayor of Iligan regarded the floods as the worst in the city's history. More than 2,000 people were rescued from the hardest hit areas.
A massive relief operation involving the evacuation of 100,000 people occurred on the morning of December 17, 2011. Approximately 20,000 soldiers were mobilized to assist in recovery efforts and evacuations. The Philippine Coast Guard was dispatched to search for missing people after villages were reported to have been swept out to sea. Sixty people were rescued off the coast of El Salvador, Misamis Oriental and another 120 in the waters near Opol township. President Benigno Aquino III visited Cagayan de Oro and Iligan on December 20, 2011, and declared a state of national calamity in the affected provinces. The total cost of damages to agriculture and infrastructure is estimated at P999.9 million according to the National Disaster Risk Reduction and Management Council. The President also appealed to its citizens to help the victims in their way of celebrating Christmas in his Christmas Message.
International aid and assistance 
Overseas humanitarian aid is pouring in for victims of Severe Tropical Storm Sendong (Washi) in Northern Mindanao, in the Philippines.
Six members of the Swiss Humanitarian Aid Unit were sent to Mindanao to ensure access to clean drinking water.
On December 21, the United Nations Emergency Relief Agency released $3 million in funds to improve water and sanitation. On December 22, the United Nations Department of Humanitarian Affairs announced a plan to raise $26.8 million in aid for victims of Severe Tropical Storm Washi. United Nations Secretary-General Ban Ki-moon sympathized with the Philippine Government and stated "the [United Nations] would extend whatever help is needed by those who were affected by the disaster." The United Nations High Commissioner for Refugees also pledged to send 42 metric tons of aid to the country. The United Nations Children's Fund also appealed for $4.2 million to be sent to the Philippines.
The United States provided $100,000 in funds to support relief efforts. The country's ambassador, Harry K. Thomas Jr., expressed his "heartfelt condolences and sympathies" to those affected by the storm. Immediate assistance was to be provided by the United States Agency for International Development's Office of Foreign Disaster Assistance. Non-food items such as hygiene kits, water purification tablets, and containers were to be sent to the Philippines.
Due to its high death toll, PAGASA announced that the name, Sendong, would be stricken off their tropical cyclone naming lists. In February 2012, the ESCAP/WMO Typhoon Committee announced that Washi will also be retired on its naming lists and was replaced with the name Hato. In June 2012, PAGASA selected the name Sarah to replace Sendong.
See also 
- Tropical Depression Winnie
- Tropical Storm Thelma
- Typhoon Bopha (2012)
- Typhoons in the Philippines
- 2011 Southeast Asian floods
- ABS-CBN.com: Sendong makes landfall at Palawan
- Final Report of Tropical Storm Sendong
- "Significant Tropical Weather Outlook for the Western and South Pacific Oceans". Joint Typhoon Warning Center. United States Navy. December 12, 2011. Retrieved December 23, 2011.
- "Tropical Cyclone Formation Alert". Joint Typhoon Warning Center. United States Navy. December 13, 2011. Retrieved December 23, 2011.
- "High Seas Forecast". Japan Meteorological Agency. December 13, 2011. Retrieved December 23, 2011.
- "Tropical Depression 27W Advisory Number 001". Joint Typhoon Warning Center. United States Navy. December 13, 2011. Retrieved December 23, 2011.
- "Tropical Storm 27W Advisory Number 005". Joint Typhoon Warning Center. United States Navy. December 14, 2011. Retrieved December 23, 2011.
- "Tropical Depression Sendong Advisory One". Philippine Atmospheric, Geophysical and Astronomical Services Administration. December 15, 2011. Retrieved December 24, 2011.
- "Tropical Depression 27W Advisory Number 008". Joint Typhoon Warning Center. United States Navy. December 15, 2011. Retrieved December 24, 2011.
- "Tropical Storm Washi Tropical Cyclone Advisory". Japan Meteorological Agency. December 15, 2011. Retrieved December 24, 2011.
- "Tropical Storm 27W (Washi) Advisory Number 011". Joint Typhoon Warning Center. United States Navy. December 15, 2011. Retrieved December 24, 2011.
- "Hundreds die as tropical storm Washi sweeps across Philippines". Associated Press. The Telegraph. December 17, 2011. Retrieved December 17, 2011.
- "Storm-triggered floods ravage southern Philippines, kill at least 436". Associated Press. The Washington Post. December 17, 2011. Retrieved December 17, 2011.
- Ramos, Benito T.. Final Report on the Effects and Emergency Management re Tropical Storm “Sendong” (Washi). National Disaster Risk Reduction and Management Center. Archived from the original on 2012-02-24. http://www.ndrrmc.gov.ph/attachments/article/358/Final%20Report%20re%20TS%20Sendong,%2015%20-%2018%20December%202011.pdf. Retrieved 2012-02-24.
- "Storms pound Philippines in the thick of night, kill at least 436". MSNBC. December 17, 2011. Retrieved December 17, 2011.
- Sun.Star: Aquino declares state of national calamity
- "Effects of Tropical Storm "Sendong" (Washi) and Emergency Operations". National Disaster Risk Reduction and Management Council. December 30, 2011. Retrieved December 30, 2011.
- "PNoy airs Christmas aid call for Sendong victims". Foreign aid pours in for disaster victims. abs-cbnNEWS.com. Retrieved 26 December 2011.
- Noemi M. Gonzales and Johanna Paola D. Poblete (December 22, 2011). "UN issues $28.6-million international appeal for victims". Business World Online. Retrieved December 23, 2011.
- "Denmark sends emergency aid to disaster areas in the Philippines". ScandAsia. December 23, 2011. Retrieved December 23, 2011.
- "EC mobilizes funds to help ‘Sendong’ victims". Inquirer. December 23, 2011. Retrieved December 23, 2011.
- Roy C. Mabasa (December 22, 2011). "UN launches revised aid program". Manila Bulletin. Retrieved December 23, 2011.
- "Switzerland sends experts to the Philippine disaster area". Government of Switzerland. ReliefWeb. December 22, 2011. Retrieved December 23, 2011.
- "British Red Cross sends funds to support typhoon stricken Philippines". British Red Cross. ReliefWeb. December 22, 2011. Retrieved December 23, 2011.
- "$4.2 million UNICEF appeal for Philippine flood victims". Agence France-Presse. Inquirer. December 20, 2011. Retrieved December 23, 2011.
- "U.S. provides aid to support Tropical Storm Sendong relief efforts". United States Department of State. ReliefWeb. December 22, 2011. Retrieved December 23, 2011.
- "Government will no longer use Sendong to name typhoons". Sun Star Manilla. 2011-12-23. Retrieved 2011-12-26.
- "Forty-Fourth Session of Typhoon Committee". Typhoon Committee. 2012-02. Retrieved 2012-02-28.
|Wikimedia Commons has media related to: Tropical Storm Washi|
- RSMC Tokyo - Typhoon Center
- JTWC Best Track Data of Tropical Storm 27W (Washi)