Tropical Storm Thelma

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Tropical Storm Thelma (Uring)
Tropical storm (JMA scale)
Tropical storm (SSHWS)
TS Thelma 04 nov 1991 0511Z.jpg
Tropical Storm Thelma approaching the Philippines on November 4
FormedNovember 1, 1991
DissipatedNovember 8, 1991
Highest winds 10-minute sustained:75 km/h (45 mph)
1-minute sustained:85 km/h (50 mph)
Lowest pressure992 hPa (mbar); 29.29 inHg
Fatalities5,081  8,165 total (4,922 dead solely in Ormoc)
Damage$27.67 million (1991 USD)
Areas affected Philippines, Vietnam
Part of the 1991 Pacific typhoon season

Tropical Storm Thelma, known in the Philippines as Tropical Storm Uring, was one of the deadliest tropical cyclones in Philippine history, killing at least 5,081 people. Forming out of a tropical disturbance on November 1, 1991, several hundred kilometers north-northeast of Palau, the depression that would become Thelma tracked generally westward. After turning southwestward in response to a cold front, the system intensified into a tropical storm on November 4 as it approached the Philippines. Hours before moving over the Visayas, Thelma attained its peak intensity with estimated ten-minute sustained winds of 75 km/h (45 mph) and a barometric pressure of 992  mbar (hPa; 29.29  inHg). Despite moving over land, the system weakened only slightly, emerging over the South China Sea on November 6 while retaining gale-force winds. Thelma ultimately succumbed to wind shear and degraded to a tropical depression. On November 8, the depression made landfall in Southern Vietnam before dissipating hours later.

Tropical cyclone Is a rotating storm system

A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".

History of the Philippines Wikimedia history article

The history of the Philippines is believed to have begun with the arrival of the first humans using rafts or boats at least 67,000 years ago as the 2007 discovery of Callao Man suggested. Negrito groups first inhabited the isles. Groups of Austronesians later migrated to the islands.

Palau republic in Oceania

Palau, officially the Republic of Palau, is an island country located in the western Pacific Ocean. The country contains approximately 340 islands, forming the western chain of the Caroline Islands in Micronesia, and has an area of 466 square kilometers (180 sq mi). The most populous island is Koror. The capital Ngerulmud is located on the nearby island of Babeldaob, in Melekeok State. Palau shares maritime boundaries with the Philippines, Indonesia, and the Federated States of Micronesia.


While passing over the Philippines, Thelma's interaction with the high terrain of some of the islands resulted in torrential rainfall. Through the process of orographic lift, much of the Visayas received 150 mm (6 in) of rain; however, on Leyte Island there was a localized downpour that brought totals to 580.5 mm (22.85 in). With the majority of this falling in a three-hour span, an unprecedented flash flood took place on the island. Much of the land had been deforestated or poorly cultivated and was unable to absorb most of the rain, creating a large runoff. This water overwhelmed the Anilao–Malbasag watershed and rushed downstream. Ormoc City, located past where the Anilao and Malbasag rivers converge, suffered the brunt of the flood. In just three hours, the city was devastated with thousands of homes damaged or destroyed. A total of 4,922 people were killed in the city alone, with 2,300 perishing along the riverbank.

Orographic lift

Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation.

Deforestation removal of forest and conversion of the land to non-forest use

Deforestation, clearance, clearcutting or clearing is the removal of a forest or stand of trees from land which is then converted to a non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests.

Drainage basin Area of land where precipitation collects and drains off into a common outlet

A drainage basin is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. The drainage basin includes all the surface water from rain runoff, snowmelt, and nearby streams that run downslope towards the shared outlet, as well as the groundwater underneath the earth's surface. Drainage basins connect into other drainage basins at lower elevations in a hierarchical pattern, with smaller sub-drainage basins, which in turn drain into another common outlet.

Outside of Ormoc City, 159 people were killed across Leyte and Negros Occidental. Throughout the country, at least 5,081 people lost their lives while another 1,9413,084 were missing and presumed dead. This made Thelma the deadliest tropical cyclone in Philippine history, surpassing a storm in 1867 that killed 1,800, [1] [2] until later surpassed by Typhoon Haiyan (Yolanda) in 2013 which killed at least 6,300 people. [3] A total of 4,446 homes were destroyed while another 22,229 were damaged. Total losses amounted to $27.67 million. [nb 1] Initially, it took over 24 hours for word of the disaster to reach officials due to a crippled communication network around Ormoc City. Within a few days, emergency supply centers were established and aid from various agencies under the United Nations and several countries flowed into the country. A total of $5.8 million worth of grants and materials was provided collectively in the international relief effort.

Negros Occidental Province in Western Visayas, Philippines

Negros Occidental, also known as Occidental Negros or Western Negros, is a province located in the region of Western Visayas, in the Philippines. It occupies the northwestern half of the large island of Negros, and borders Negros Oriental, which comprises the southeastern half. Known as the "Sugarbowl of the Philippines", Negros Occidental produces more than half the nation's sugar output.

Typhoon Haiyan West pacific category 5 in 2013

Typhoon Haiyan, known as Super Typhoon Yolanda in the Philippines, was one of the most powerful tropical cyclones ever recorded. On making landfall, Haiyan devastated portions of Southeast Asia, particularly the Philippines. It is the deadliest Philippine typhoon on record, killing at least 6,300 people in that country alone. In terms of JTWC-estimated 1-minute sustained winds, Haiyan is tied with Meranti for being the strongest landfalling tropical cyclone on record. In January 2014, bodies were still being found.

United Nations Intergovernmental organization

The United Nations (UN) is an intergovernmental organization that was tasked to maintain international peace and security, develop friendly relations among nations, achieve international co-operation and be a centre for harmonizing the actions of nations. The headquarters of the UN is in Manhattan, New York City, and is subject to extraterritoriality. Further main offices are situated in Geneva, Nairobi, and Vienna. The organization is financed by assessed and voluntary contributions from its member states. Its objectives include maintaining international peace and security, protecting human rights, delivering humanitarian aid, promoting sustainable development and upholding international law. The UN is the largest, most familiar, most internationally represented and most powerful intergovernmental organization in the world. In 24 October 1945, at the end of World War II, the organization was established with the aim of preventing future wars. At its founding, the UN had 51 member states; there are now 193. The UN is the successor of the ineffective League of Nations.

Meteorological history

Map plotting the track and the intensity of the storm, according to the Saffir-Simpson scale Thelma 1991 track.png
Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale

In late October 1991, a tropical disturbance developed near the Caroline Islands. Tracking generally west-northwestward, the system gradually became more defined. On October 31, convection associated with the system quickly increased, prompting the issuance of a Tropical Cyclone Formation Alert from the Joint Typhoon Warning Center (JTWC). [4] Early on November 1, the Japan Meteorological Agency (JMA) began monitoring the system as a tropical depression, at which time the system was situated roughly 415 km (260 mi) north-northeast of Palau. [5] Following a satellite-derived surface wind estimate of 45 km/h (30 mph) later that day, the JTWC also began monitoring the low as a tropical depression. Initially, forecast models showed the system continuing on an arcing path out to sea; however, the system turned westward on November 2 and threatened the Philippines. [4] Due to the cyclone's proximity to the country, the Philippine Atmospheric, Geophysical and Astronomical Services Administration also monitored the storm and assigned it with the local name Uring. [6] Late on November 3, the depression turned west-southwestward towards the Visayas in response to an approaching cold front, an event typical of late-season cyclones in the basin. [7] On November 4, both the JTWC and JMA upgraded the system to a tropical storm, with the latter assigning it the name Thelma. [4] [5]

Caroline Islands archipelago

The Caroline Islands are a widely scattered archipelago of tiny islands in the western Pacific Ocean, to the north of New Guinea. Politically they are divided between the Federated States of Micronesia in the eastern part of the group, and Palau at the extreme western end. Historically, this area was also called Nuevas Filipinas or New Philippines as they were part of the Spanish East Indies and governed from Manila in the Philippines.

Atmospheric convection

Atmospheric convection is the result of a parcel-environment instability, or temperature difference layer in the atmosphere. Different lapse rates within dry and moist air masses lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to increased winds, cumulus cloud development, and decreased surface dew points. Moist convection leads to thunderstorm development, which is often responsible for severe weather throughout the world. Special threats from thunderstorms include hail, downbursts, and tornadoes.

Tropical Cyclone Formation Alert

A Tropical Cyclone Formation Alert (TCFA) is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Fleet Weather Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone forming from a tropical disturbance that has been monitored. Such alerts are generally always issued when it is fairly certain that a tropical cyclone will form and are not always released prior to cyclone genesis, particularly if the cyclone appears suddenly. The TCFA consists of several different checks that are performed by the on-duty meteorologist of the system and its surroundings. If the condition being checked is met, a certain number of points are given to the system.

Hours before striking the Philippines on November 4, both agencies reported Thelma to have reached its peak intensity. The JTWC estimated the storm to have attained one-minute sustained winds of 85 km/h (50 mph) while the JMA estimated ten-minute sustained winds at 75 km/h (45 mph). Additionally, its barometric pressure reached 992  mbar (hPa; 29.29  inHg). [4] [5] Thelma soon made landfall in Samar before weakening to a minimal tropical storm. Maintaining gale-force winds, the system eventually passed over Palawan Island on November 6 before moving over the South China Sea. Despite being back over water, strong wind shear prevented re-intensification and caused Thelma to weaken to a tropical depression by November 7. Now moving westward, the depression eventually made its final landfall over the Mekong River Delta in Southern Vietnam on November 8. [4] Over the next couple of days the system weakened into an area of low pressure as it moved westwards, before it moved into the Andaman Sea during November 10. [8] Once in the Andaman Sea, the systems remnants contributed to the formation of the Karaikal tropical cyclone during the next day. [8]

Bar (unit) non-SI unit of pressure

The bar is a metric unit of pressure, but is not approved as part of the International System of Units (SI). It is defined as exactly equal to 100,000 Pa, which is slightly less than the current average atmospheric pressure on Earth at sea level.

Pascal (unit) SI unit of pressure

The pascal is the SI derived unit of pressure used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength. It is defined as one newton per square metre. It is named after the French polymath Blaise Pascal.

Samar island of the Philippines

Samar is the third largest island in the Philippines. Located in eastern Visayas, within central Philippines. The island is divided into three provinces: Samar, Northern Samar, and Eastern Samar. These three provinces, along with the provinces on the nearby islands of Leyte and Biliran are part of the Eastern Visayas region.


Tropical Storm Thelma over the Visayas on November 5 TS Thelma 05 nov 1991 0459Z.jpg
Tropical Storm Thelma over the Visayas on November 5

Tropical Storm Thelma struck the Philippines just five months after the Ultra-Plinian eruption of Mount Pinatubo. The eruption resulted in the deaths of roughly 800 people and left nearly 1 million homeless. The country's government was reportedly struggling to deal with the scope of the disaster and the addition of Thelma worsened the situation. [9]

Plinian eruption type of volcanic eruption

Plinian eruptions or Vesuvian eruptions are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in 79 AD, which destroyed the ancient Roman cities of Herculaneum and Pompeii. The eruption was described in a letter written by Pliny the Younger, after the death of his uncle Pliny the Elder.

Striking the nation as a weak tropical storm, winds from Thelma gusted up to 95 km/h (60 mph) in Tacloban; [10] these winds caused no known damage. The main destructive force associated with the cyclone was the tremendous rainfall it produced. More than 150 mm (6 in) of rain across much of the Visayas, resulting in widespread flooding. [4] In Tacloban, 140.2 mm (5.52 in) fell over a 24‑hour span. The heaviest rain occurred on Leyte Island due to orographic lift, which brought large quantities of moisture into the atmosphere over a relatively small area. Additionally, monsoonal winds to the southwest of Thelma converged over the island, further enhancing the precipitation. Near the city of Ormoc, a Philippine National Oil Company rain gauge measured 580.5 mm (22.85 in) of precipitation, the highest in relation to the storm. Of this, approximately 500 mm (20 in) fell during a three-hour span around noon local time on November 5. [7] Initially, residents believed that waterspouts transported tremendous amounts of water to the island, triggering the floods. This notion was quickly dismissed as improbable, however. [11]

The hardest hit region was Leyte, where more than 4,000 people lost their lives. A total of 4,446 homes were destroyed while another 22,229 were damaged. The majority of casualties and damage took place in Ormoc when a flash flood devastated the city. At least 81 people were killed outside Ormoc and another 14 went missing; 42 lost their lives in Burauen. [11] The entire island of Leyte was left without power and many areas were isolated as roads were washed away. [12] Another 78 people perished and 70 others were left missing in Negros Occidental. Losses from the storm amounted to $27.67 million; $18.94 million in Leyte and $8.73 million in Negros Occidental. A total of 598,454 people were affected while an estimated 43,000 people were left homeless by the storm across the Philippines. [13] [14]

Ormoc City tragedy

Location of Ormoc on Leyte Island Ph locator leyte ormoc.png
Location of Ormoc on Leyte Island

The greatest tragedy during Tropical Storm Thelma took place in the city of Ormoc after torrential rains overwhelmed the Anilao–Malbasag watershed, sending flood waters rushing down the deforested mountainside. [15] This water flowed into the Anilao and Malbasag rivers, located north of Ormoc. [16] The watershed, covering an area of 4,567  hectares (11,285  acres), is only 3.3 percent forested, with the remainder being used for agricultural and private purposes. [15] According to a study in 1990, roughly 90 percent of the watershed had been converted into coconut and sugarcane plantations. The majority of this land was improperly cultivated since the 1970s, making conditions worse than they normally would have been. [17] The natural structure of the mountains further contributed to the floods, with slopes as steep as 60 percent grade in some areas. In heavy rain events, this feature leaves the upper two-thirds of the mountain range unstable. [16] In the two hours prior to the heaviest rains, the soil in the watershed became saturated, greatly lessening its effectiveness at absorbing further rains. As a result, the tremendous rains that occurred just prior to the flood, during which rainfall rates reached 167 mm (6.6 in) per hour, the land was unable to absorb a majority of the rain. Many landslides ranging from 1 to 3 m (3.3 to 9.8 ft) deep and 50 to 100 m (160 to 330 ft) wide occurred across the region. [15] Altogether, rains were twice as heavy as the land could handle and the many landslips doubled the volume of fluids. [18] At various points along rivers, temporary dams created by debris, namely trees, allowed a build up of water upstream. In some instances, waters reached a depth of 10 m (33 ft) before the dams collapsed. [16] Normally, it takes water in the Anilao and Malbasag rivers roughly 3.6 and 5.6 days, respectively, to reach Ormoc City; however, it only took one hour during the flood. [15]

Ormoc City itself is located in a flood-prone area, with the Anilao and Malbasag rivers converging just north of the city and taking a 90 degree turn towards the bay. In addition to the natural dangers of the river, poorly designed structures on the river made conditions worse. [17] The majority of construction along the river did not take flooding threats into account, and actually increased the threat of these events. [18] Concrete walls and levees were built into the river rather than on the banks, leading to faster debris damming. Lastly, just after the turn was the Cogon Bridge. This structure constricted the river by as much as 50 percent, enhancing the build up of water. The turn became the final trigger in the disaster as it created an "instantaneous backwater effect," causing massive volumes of water to over-top the riverbank. [17] Around 11:00 a.m. local time on November 5, approximately 22,835 km3 (5,480 mi3) of water inundated 25 km2 (15.5 mi2) of the city. [13] [16] In just 15 minutes, the water rose by 2.1 m (7 ft) and further rose to 3.7 m (12 ft) within an hour. [16] [19] The flooding lasted for roughly three hours, leaving up to 0.6 m (2.0 ft) of sediment behind. [16]

"The waters kept rising. We had to place our children on top of the refrigerator. Still, the waters kept going up so we all had to climb to the roof. But perhaps we are bless. We all survived."

Survivor from Isle Verde [20]

The flood struck the city with little to no warning, catching all those in its path off-guard. [21] Numerous low-income families lived along the banks of the river, despite being such a high-risk area. Residential and commercial areas were also set up along reclaimed embankments that restricted river flow. Additionally, squatters were allowed to live along the banks of the Anilao river in an area called Isle Verde. [17] Roughly 2,500 people lived on this reclaimed land prior to the flood. The majority of fatalities took place along the banks of the river, with most drowning or being buried in mud or debris. A survivor described the initial event as a gigantic wave crashing over the banks and flooding the city. Isle Verde was virtually wiped out and out of the original 2,500 people that lived there, only 200 survived. It became known as the "Isle of Death" to survivors. [20] Residents reported hundreds of bodies floating down rivers in the area. [19] The force of the water and mud was enough to crack the walls of city hall. [12] Nearly 3,000 homes were destroyed and more than 11,000 others were damaged. [11] In the city alone, officials confirmed that 4,922 people were killed and another 1,8573,000 were left missing. [21] [22] Additionally, 3,020 people were injured. [11] The majority of those missing were likely swept out to sea by the flood and presumed dead. [12] Two days after the storm, several bodies of those swept out to sea washed back ashore. [23] Officials stated that the death toll could have been in the tens of thousands had the flood occurred at night rather than in the middle of the day. [12]


"It looked like it was a Nazi [death] camp. Children and old people were piled on top of each other."

Cebu Provincial Governor Lito Osmena [12]

Initially, it took more than 24 hours for word of the level of devastation to reach officials in Manila as communications across Leyte were largely destroyed. [19] By November 7, search and rescue operations were underway across Leyte and Negros Occidental. The first shipment of relief supplies, consisting of food rations, rice, sardines, and used clothing, was to be shipped from Cebu later that day. [13] On November 8, Philippine President Corazon Aquino declared all of Leyte a disaster area. [24] A Philippine Navy vessel set out with heavy earth-moving machinery and the Philippine Air Force deployed aircraft to assist in rescue efforts. Relief efforts in Ormoc City were hampered by a lack of clear roads and fuel. Amateur radio reports stated that an AC-130 was able to land at a local airport but materials had to be moved by helicopter from there since roads were blocked. [13] Relief efforts were also hampered by continuing rains and the rough terrain of the affected region. [19] By November 11, approximately 8,300 families had been rescued and another 7,521 were evacuated from affected regions. [13]

Supply distribution centers were established in Ormoc, providing residents with food, water, and materials, by November 11. [13] People were given a can of sardines and 1 kg (2.2 lb) of rice at these centers. [24] These centers were only able to operate in daylight though due to a lack of fuel and transportation. Water was supplied in limited quantities from Cebu. Medical and sanitation teams were deployed throughout the province, with many coming from surrounding areas. [13] Residents searched through debris for lumber to construct makeshift coffins while others stacked bodies to be picked up by wheelbarrows or trucks. [19] Officials had difficulty determining how to best deal with mass casualties as bodies lay across the Ormoc region. Many were found in the coastal barangays of Linao, Camp Downes, and Bantigue as well as the Ormoc pier. [22] In order to prevent the spread of disease, mass graves were dug, with 700 bodies buried on November 8. Dump trucks were used to transport the dead to these sites as quickly as possible. [25] As decomposition set in, residents stated that "[the] putrid smell was unbearable." Even months after the storm, bodies were occasionally discovered, some found in drainage systems. [22] By November 10, four navy vessels were searching debris in the waters near Ormoc for bodies; 16 were recovered that day with more believed to be submerged in the bay. [26] Roads surrounding the city were finally cleared by November 12; however, electricity remained out. With the deployment of medical teams from Japan, hospitals in the region returned to full capacity. By November 22, electricity and water had been 70 percent and 60 percent restored, respectively. The emergency phase of assistance ended on November 29 and coordination of disaster relief was returned to the Philippines. By that time, national aid to Ormoc reached $1.1 million, with more than half coming from a presidential grant. [13]

Deadliest Philippine typhoons
1 "Haiphong" 188120,000 [27]
2 Haiyan (Yolanda) 2013 6,300 [28]
3 Thelma (Uring) 1991 5,101–8,000 [29]
4 Bopha (Pablo) 2012 1,901 [29]
5"Angela"18671,800 [30]
6 Winnie 2004 1,593 [30]
7"October 1897"18971,500 [30] [31]
8 Ike (Nitang) 1984 1,363 [29]
9 Washi (Sendong) 2011 1,268 [29] [32]
10 Trix 1952 995 [29]

On November 7, despite no official appeal for international aid, the governments of France and the United States provided $34,783 and $25,000 in funds. The request for assistance came the following day, with the Philippines requesting food, water, medicine, emergency supplies, and heavy machinery. A team from the United Nations Disaster Relief Organization, specializing with relief coordination and flood management, was also sent. The Red Cross appealed for $418,000 to support 15,000 families for one month. A cash grant of $17,300 from the United Kingdom was received on November 8. [13] Two United States Air Force AC-130s from Subic bay naval base flew to Cebu carrying ready-to-eat meals. [25] International funding reached $2.5 million on November 12, with grants of $1.05 million, $1 million, $188,000 from the Netherlands, Japan, and Australia respectively. Additionally, the United States provided 55,000 packages of food rations. This total nearly doubled two days later with grants from the United Nations Development Programme, World Food Programme, World Vision International, Médecins Sans Frontières, Caritas, various branches of the Red Cross, and the governments of Canada and New Zealand. Ultimately, approximately $5.8 million was provided in international assistance from 13 nations, the United Nations, the Red Cross, and various non-governmental organizations. [13]

Isle Verde, where approximately 2,300 people were killed, was declared uninhabitable by officials; however, residents still returned to the area due to a need for land. Eventually, signs that used to warn people not to stay on the islet were eventually taken down and people were no longer warned not to live there. A resettlement community was constructed months later, with plans to house 912 of the 2,668 families that needed to be moved from the area. Those that were not moved were left on Isle Verde despite orders not to stay there. [20] Another resettlement project for 700 families was planned at the cost of $1 million. [13]

The sheer magnitude of the flood event in the Anilao–Malbasag watershed made the region more vulnerable to future flood events. Hillsides became more unstable and the rivers themselves were clogged with debris, raising their water levels and widening their banks. In a post-disaster assessment in October 1992, it was stated that swift cooperation of all agencies from local to governmental was necessary to prevent tragedies of similar caliber in the future. [18] It was urged that residents still living along the river banks be relocated to safer areas; however, by the time of the report, people had already begun repopulating the area. As a way of avoiding similar breaching of the riverbank, it was suggested that the two rivers be dredged and possibly re-channeled. Several points were also brought up about rehabilitating the landscape of the watershed: reforestation, contoured farming, and redesigning of plantations to better retain rainwater. [33] Long-term rehabilitation of the watershed was deemed necessary in addition to repairing infrastructure in Ormoc. [18]

In 1993, following a request by the Philippine Government, the Japan International Cooperation Agency conducted as study on flood control for Ormoc and other cities across the country. In 1998, a 800 million ($20.6 million USD) construction project for flood mitigation was approved and later completed in 2001. That year, Tropical Depression Auring caused flooding of similar magnitude to Thelma; however, the waters were properly diverted to the sea. A sculpture and monument to the victims, designed by architect Maribeth Ebcas and artist Florence Cinco respectively, called "Gift of Life" was constructed on a 1.3 km2 (0.8 mi2) plot of land. It was designed to also depict a need to respect nature and be a message of hope for residents in Ormoc. [22]

Due to the catastrophic loss of life caused by the storm, the name Thelma was retired and replaced with Teresa. [34]

See also


  1. All damage totals are in 1991 values.

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Typhoon Ketsana, known in the Philippines as Tropical Storm Ondoy, was the second-most devastating tropical cyclone of the 2009 Pacific typhoon season, causing $1.09 billion in damages and 747 fatalities, only behind Morakot earlier in the season, which caused 789 deaths and damages worth $6.2 billion. Ketsana was the sixteenth tropical storm, eighth typhoon, and the second super typhoon in the season. It was the most devastating typhoon to hit Manila, surpassing Typhoon Patsy (Yoling) in 1970.

Typhoon Dan (1989) Pacific typhoon in 1989

Typhoon Dan, known in the Philippines as Typhoon Saling, was the third of a series of tropical cyclones that impacted the Philippines and Vietnam in October 1989. The storm developed on October 6, and tracked generally westward throughout its course. After crossing Luzon, the typhoon emerged into the South China Sea and reached its peak intensity, with sustained 10-minute winds of 140 km/h (85 mph), 1-minute winds of 130 km/h (80 mph), and a minimum barometric pressure of 960 millibars. The storm moved ashore in central Vietnam and dissipated after moving inland. The storm caused extensive damage throughout its course. In the Philippines, Dan left hundreds of thousands homeless and killed 58 people. Power outages were extensive in the Manila region. In Vietnam, the storm's high winds and heavy rains caused extensive damage and loss of life. More than 500,000 structures were damaged or destroyed and at least 43 people were killed across the country.

Tropical Depression Winnie Pacific tropical depression in 2004

Tropical Depression Winnie was a weak, but catastrophic tropical cyclone that killed nearly 1,600 people after triggering widespread flooding in the Philippines.

Tropical Storm Linfa (2003) Pacific tropical storm in 2003

Severe Tropical Storm Linfa, known in the Philippines as Tropical Storm Chedeng, brought deadly flooding to areas of the Philippines and Japan in May and June 2003. The fifth named storm within the northwestern Pacific that year, Linfa developed as a tropical depression just off the western coast of Luzon on May 25. The disturbance quickly intensified to reach tropical storm intensity a few hours after cyclogenesis. However, intensification leveled off as Linfa executed a small clockwise loop before a subsequent landfall on Luzon on May 27. Due to land interaction the storm temporarily weakened and decoupled before reforming in the Philippine Sea. Afterwards Linfa began reintensifying and reached its peak intensity on May 29 with maximum sustained winds of 100 km/h (65 mph) and a barometric pressure of 980 mbar. Following its peak the tropical storm began to deteriorate and transitioned into an extratropical cyclone on May 30; these extratropical remnants continued to track northward through Japan before dissipating in the Sea of Okhotsk on June 4.

Tropical Storm Washi Pacific severe tropical storm in 2011

Severe Tropical Storm Washi, known in the Philippines as Tropical Storm 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.

The 2012 Luzon southwest monsoon floods, was an eight-day period of torrential rain and thunderstorms in the Philippines from August 1 to August 8, 2012. Its effects centered on Metro Manila, the surrounding provinces of the Calabarzon Region and the provinces of Region 3. Not a typhoon in its own right, the storm was a strong movement of the southwest monsoon caused by the pull of Typhoon Saola (Gener) from August 1–3, strengthened by Typhoon Haikui. It caused typhoon-like damage: the most damage caused by rain since September 2009, when Typhoon Ketsana (Ondoy) struck Metro Manila. The heavy rain caused the Marikina River to overflow, destroying areas also affected by Ketsana, triggering a landslide in the Commonwealth area and collapsing the northbound Marcos Highway.

Typhoon Son-Tinh Pacific typhoon in 2012

Typhoon Son-Tinh, known in the Philippines as Tropical Storm Ofel, was a powerful, late-forming typhoon that devastated the Philippines with tropical storm strength, and battered Northern Vietnam with hurricane-force winds at landfall on October 28, 2012. Originating from a broad area of low pressure over Palau on October 20, the system strengthened into a tropical depression by October 21, and on October 22, it became the 23rd named storm of the season.

Tropical Storm Lucille

Tropical Storm Lucille was the first tropical cyclone to have its name retired in the Western Pacific basin. Lucille was identified as a weak tropical depression on May 25, 1960, to the east of the Philippines. Tracking northwestward, the system failed to develop and warnings on it were discontinued on May 27. At the same time, a second system began organizing along the west coast of Luzon. The two systems ultimately merged into one over the Philippines between May 28 and 29. Now tracking northeastward, the system re-intensified and became a tropical storm on May 30. Lucille attained its peak intensity later that day with winds of 85 km/h (50 mph). As it accelerated over open waters, the system brushed the islands of Iwo Jima and Chichi-jima before transitioning into an extratropical cyclone on June 1. The remnants of Lucille were last noted on June 4 near the International Date Line.

Tropical Storm Trami (2013)

Severe Tropical Storm Trami, known in the Philippines as Tropical Storm Maring, was a tropical cyclone that brought heavy rains to Taiwan and East China during mid-August 2013. Trami also made a fujiwhara interaction with Tropical Depression 13W north of it. The storm also enhanced the southwest monsoon causing more than 20 casualties in the Philippines.

Tropical Storm Rumbia (2000)

Tropical Storm Rumbia, known in the Philippines as Tropical Storm Toyang, brought deadly flooding to the central and southern Philippines in November and December 2000. The last of three consecutive tropical cyclones of at least tropical storm intensity to strike the Philippines, Rumbia began as a tropical depression on November 27, gradually intensifying to reach tropical storm intensity the next day. Strengthening later stagnated, and Rumbia would weaken back to depression status as it made landfall on the central Philippines on November 30. Though the Japan Meteorological Agency (JMA) determined Rumbia to have dissipated on December 2, the Joint Typhoon Warning Center (JTWC) continued to monitor the system over the next few days as it tracked across the South China Sea. For a period of time beginning on December 5, Rumbia reorganized and strengthened back to tropical storm intensity before wind shear began to weaken the system. Located south of Vietnam on December 7, the storm's circulation center became devoid of convection, and by then Rumbia was declared by the JTWC to have dissipated.

Tropical Storm Tess (1988)

Tropical Storm Tess known in the Philippines as Tropical Storm Welpring was the second of three tropical cyclones to directly impact the Philippines in a two-week time frame in 1988. An area of disturbed weather near the Philippines was first observed on November 1. Following an increase in organization, the disturbance was designated as a tropical cyclone on November 4. Moving west, Tess steadily strengthened due to favorable conditions aloft. During the evening of November 5, Tess was estimated to have achieved its highest intensity, with winds of 115 km/h (70 mph). Rapid weakening then ensured as Tess neared Vietnam, and after making landfall in the country on November 6, Tess dissipated the next day.

Effects of the 2013 Pacific typhoon season in the Philippines

The effects of the 2013 Pacific typhoon season in the Philippines were considered some of the worst in decades. Throughout the year, series of typhoons impacted the country, with the worst damage especially death toll from Typhoon Haiyan during November.


  1. Pedro Ribera, Ricardo Garcia-Herrera and Luis Gimeno (July 2008). "Historical deadly typhoons in the Philippines". Weather. 63 (7): 196. Bibcode:2008Wthr...63..194R. doi:10.1002/wea.275.
  2. Dominic Alojado and Michael Padua (July 29, 2010). "The Twelve Worst Typhoons Of The Philippines (1947–2009)". Typhoon2000. Retrieved May 6, 2013.
  3. "Updates re Effects of Typhoo "Yolanda" (Haiyan)" (PDF). National Disaster Risk Reduction and Management Council. April 17, 2014. Archived from the original (PDF) on October 6, 2014. Retrieved April 17, 2014.
  4. 1 2 3 4 5 6 "Annual Tropical Cyclone Report: Typhoon Thelma (27W)" (PDF). Joint Typhoon Warning Center. United States Navy. 1992. pp. 132–135. Retrieved May 3, 2013.
  5. 1 2 3 "1991 Thelma (1991304N08140)". International Best Track Archive. 2013. Retrieved May 3, 2013.
  6. "Destructive Typhoons 1970-2003". National Disaster Coordinating Council. November 9, 2004. Archived from the original on November 12, 2004. Retrieved May 3, 2013.
  7. 1 2 Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991: Chapter 2: Meteorological Conditions" (PDF). Environmental Science for Social Change: 10–16. Retrieved May 3, 2013.
  8. 1 2 Report on Cyclonic Disturbances (Depressions and Tropical Cyclones) over North Indian Ocean in 1991 (PDF) (Report). India Meteorological Department. January 1992. pp. 5–6. Archived from the original on March 27, 2016. Retrieved March 27, 2016.
  9. Bob Droggin (Los Angeles Times) (November 7, 1991). "Storm-triggered mudslides, floods kill 2,300 Filipinos". The News-Journal. Manila, Philippines. p. A1. Retrieved May 6, 2013.
  10. Dominic Alojado and Michael Padua (July 29, 2010). "20 Worst Typhoons of the Philippines (1947–2009)". Typhoon2000. Retrieved May 6, 2013.
  11. 1 2 3 4 Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991 Chapter 1: The Ormoc City Tragedy" (PDF). Environmental Science for Social Change: 3–9. Retrieved May 3, 2013.
  12. 1 2 3 4 5 Associated Press (November 6, 1991). "Floods, landslides from tropical storm kill 2,337 in Philippines". The Pittsburgh Press. Tacloban, Philippines. p. A1. Retrieved May 3, 2013.
  13. 1 2 3 4 5 6 7 8 9 10 11 "Philippines Floods Nov 1991 UNDRO Situation Reports 1-8". United Nations Department of Humanitarian Affairs. ReliefWeb. November 29, 1991. Retrieved May 3, 2013.
  14. Parker, p. 400
  15. 1 2 3 4 Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991: Chapter 4: Contributing Physical Factors" (PDF). Environmental Science for Social Change: 19–29. Retrieved May 3, 2013.
  16. 1 2 3 4 5 6 Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991 Chapter 3: Flood Event" (PDF). Environmental Science for Social Change: 17–18. Retrieved May 3, 2013.
  17. 1 2 3 4 Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991: Chapter 6: Critical Social Conditions" (PDF). Environmental Science for Social Change: 30–32. Retrieved May 3, 2013.
  18. 1 2 3 4 Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991: Chapter 6: Evaluation" (PDF). Environmental Science for Social Change: 33–40. Retrieved May 3, 2013.
  19. 1 2 3 4 5 Bob Drogin (November 7, 1991). "2,300 Dead as Storm Batters the Philippines". Los Angeles Times. Manila, Philippines. Retrieved May 3, 2013.
  20. 1 2 3 Marites Dañguilan-Vitug. "The Politics of Disaster" (PDF). Philippine Center for Investigative Journalism. Retrieved May 3, 2013.
  21. 1 2 Monte L. Peterson (July 1992). "Reconnaissance Report: Flooding Resulting From Typhoon Uring In Ormoc City, Leyte Province, The Philippines" (PDF). United States Army Corps of Engineers. pp. 1–49. Retrieved May 3, 2013.
  22. 1 2 3 4 Cris Evert Lato (November 12, 2010). "Ormoc rises from flash flood tragedy". The Inquirer. Ormoc, Philippines.
  23. Associated Press (November 7, 1991). "Tropical Storm Thelma: Survivors looks for relatives in aftermath". The Vindicator. Ormoc, Philippines. p. A6. Retrieved May 6, 2013.
  24. 1 2 Associated Press (November 9, 1991). "The Philippines: Search continues for bodies of victims". The Vindicator. Manila, Philippines. p. A3. Retrieved May 7, 2013.
  25. 1 2 Associated Press (November 8, 1991). "Mass burials mark Thelma's destruction". The Vindicator. Ormoc, Philippines. p. A8. Retrieved May 7, 2013.
  26. Associated Press (November 10, 1991). "2nd storm heads to ravaged Philippines". The Times-News. Manila, Philippines. p. 9A. Retrieved May 7, 2013.
  27. Philippine Storm Surge History. Project NOAH, University of the Philippines. 23 November 2013. Archived from the original on 8 November 2014. Retrieved 29 November 2013.
  28. del Rosario, Eduardo D. (April 2014). FINAL REPORT Effects of Typhoon YOLANDA (HAIYAN) (pdf) (Report). NDRRMC. Retrieved 21 April 2014.
  29. 1 2 3 4 5 Alojado, Dominic (2015). Worst typhoons of the philippines (1947-2014) (pdf) (Report). Weather Philippines. Retrieved 25 September 2015.
  30. 1 2 3 "10 Worst Typhoons that Went Down in Philippine History". M2Comms. 3 August 2016. Retrieved 3 August 2016.
  31. Lotilla, Raphael (20 November 2013). "Flashback: 1897, Leyte and a strong typhoon". Rappler. Retrieved 10 July 2014.
  32. Ramos, Benito T. (10 February 2014). Final Report on the Effects and Emergency Management re Tropical Storm SENDONG (WASHI) (pdf) (Report). NDRRMC. Retrieved 10 February 2014.
  33. Environmental Research Division, Manila Observatory (October 1992). "The Ormoc City Tragedy of November 5, 1991: Chapter 7: Recommendations" (PDF). Environmental Science for Social Change: 41–43. Retrieved May 3, 2013.
  34. Xiaotu Lei and Xiao Zhou (Shanghai Typhoon Institute of China Meteorological Administration) (February 2012). "Summary of Retired Typhoons in the Western North Pacific Ocean". Tropical Cyclone Research and Review. 1 (1): 23–32. doi:10.6057/2012TCRR01.03 . Retrieved May 3, 2013.