Typhoon Dan (1989)
Encyclopedia
Typhoon Dan was a minimal typhoon that affected 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 damaged structures and caused seven casualties.
near the island of Chuuk
. An advisory by the Joint Typhoon Warning Center
(JTWC) assessed the system as having a "poor" chance to develop due to strong wind shear
in the region. A day later, the potential of development was adjusted to "fair". On October 8, the wind shear relented and a well-defined band
persisted near the storm's center of circulation. As a result, a Tropical Cyclone Formation Alert was issued. That same day, the Japan Meteorological Agency
(JMA) classified the storm as a tropical depression. At 1200 UTC, the JTWC issued their first warning on Tropical Depression 29W. At the time, it was centered about 70 mi (112.7 km) northeast of Yap
.
About 18 hours later, the depression was upgraded to a tropical storm and given the name Dan. The cyclone moved westward at 17 to 23 mph (27.4 to 37 km/h), and convection continued to mature. Outflow
was good across most of the system, except the northwestern corner where it was restricted by interaction with a nearby typhoon. The JMA upgraded it to a tropical storm on October 9; both agencies recognized it as a typhoon the next day after an eye
became visible and outflow improved in the northwestern quadrant. Dan made landfall on the southeastern coast of Luzon
in the Philippines
, and its center tracked just south of the Ninoy Aquino International Airport
.
Dan crossed over the island and emerged into the South China Sea
, having lost its eye feature and weakened back into a tropical storm. Convection soon redeveloped as the storm moved northwestward through warm waters. The JTWC reports that Dan reattained typhoon status at 0000 UTC on October 12, although it according to the JMA it did so 24 hours earlier. The typhoon continued to intensify, and the JTWC estimates that it reached its peak intensity at 0600 UTC, with 1-minute maximum sustained winds of 130 km/h (80 mph). The JMA indicates that Dan peaked slightly afterward, with 10-minute sustained winds of 140 km/h (85 mph) and a minimum barometric pressure reading of 960 millibars.
The storm passed about 70 mi (112.7 km) south of Hainan Island and weakened somewhat. Increased wind shear further deteroirated the system as it approached the coast of Vietnam
. The storm moved inland at around 1200 UTC on October 13, at which point the JMA downgraded it to a severe tropical storm and the JTWC issued their final advisory on the disturbance. The circulation ultimately dissipated over the mountainous terrain and its remnants continued to move westward into Laos
.
($30.10700 USD). The storm triggered flooding and landslides, while high winds brought down trees and powerlines. The second typhoon to strike the country within a week, Dan forced schools and government offices to close. Approximately 250,000 people were left homeless, and dozens of fishermen went missing offshore. In the Manila
area, near-total power loss was reported. President Corazon Aquino
issued a "state of calamity" there and in surrounding areas. As the storm progressed westward, it buffeted Hainan Island with gale-force winds.
Damage in Vietnam was also extensive. The typhoon flooded about 230000 acre (93,077.8 ha) of land and brought down utility lines. The high winds, reportedly blowing at 75 mph (120.7 km/h), ripped roofs off houses. Large storm tide
s along the coast pushed flood waters ashore. The storm killed seven people in the country.
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
and Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
in October 1989. The storm developed on October 6, and tracked generally westward throughout its course. After crossing Luzon
Luzon
Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...
, the typhoon emerged into the South China Sea
South China Sea
The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around...
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
Manila
Manila is the capital of the Philippines. It is one of the sixteen cities forming Metro Manila.Manila is located on the eastern shores of Manila Bay and is bordered by Navotas and Caloocan to the north, Quezon City to the northeast, San Juan and Mandaluyong to the east, Makati on the southeast,...
region. In Vietnam, the storm's high winds damaged structures and caused seven casualties.
Meteorological history
On October 6, 1989, a tropical disturbance formed in the monsoon troughMonsoon trough
The monsoon trough is that portion of the Intertropical Convergence Zone which extends into or through a monsoon circulation, as depicted by a line on a weather map showing the locations of minimum sea level pressure, and as such, is a convergence zone between the wind patterns of the southern and...
near the island of Chuuk
Chuuk
Chuuk — formerly Truk, Ruk, Hogoleu, Torres, Ugulat, and Lugulus — is an island group in the south western part of the Pacific Ocean. It comprises one of the four states of the Federated States of Micronesia , along with Kosrae, Pohnpei, and Yap. Chuuk is the most populous of the FSM's...
. An advisory by the Joint Typhoon Warning Center
Joint Typhoon Warning Center
The Joint Typhoon Warning Center is a joint United States Navy – United States Air Force task force located at the Naval Maritime Forecast Center in Pearl Harbor, Hawaii...
(JTWC) assessed the system as having a "poor" chance to develop due to strong wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
in the region. A day later, the potential of development was adjusted to "fair". On October 8, the wind shear relented and a well-defined band
Rainband
A rainband is a cloud and precipitation structure associated with an area of rainfall which is significantly elongated. Rainbands can be stratiform or convective, and are generated by differences in temperature. When noted on weather radar imagery, this precipitation elongation is referred to as...
persisted near the storm's center of circulation. As a result, a Tropical Cyclone Formation Alert was issued. That same day, the Japan Meteorological Agency
Japan Meteorological Agency
The or JMA, is the Japanese government's weather service. Charged with gathering and reporting weather data and forecasts in Japan, it is a semi-autonomous part of the Ministry of Land, Infrastructure and Transport...
(JMA) classified the storm as a tropical depression. At 1200 UTC, the JTWC issued their first warning on Tropical Depression 29W. At the time, it was centered about 70 mi (112.7 km) northeast of Yap
Yap
Yap, also known as Wa'ab by locals, is an island in the Caroline Islands of the western Pacific Ocean. It is a state of the Federated States of Micronesia. Yap's indigenous cultures and traditions are still strong compared to other neighboring islands. The island of Yap actually consists of four...
.
About 18 hours later, the depression was upgraded to a tropical storm and given the name Dan. The cyclone moved westward at 17 to 23 mph (27.4 to 37 km/h), and convection continued to mature. Outflow
Outflow (meteorology)
Outflow, in meteorology, is air that flows outwards from a storm system. It is associated with ridging, or anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather...
was good across most of the system, except the northwestern corner where it was restricted by interaction with a nearby typhoon. The JMA upgraded it to a tropical storm on October 9; both agencies recognized it as a typhoon the next day after an eye
Eye (cyclone)
The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30–65 km in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the second most severe weather of a cyclone...
became visible and outflow improved in the northwestern quadrant. Dan made landfall on the southeastern coast of Luzon
Luzon
Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...
in the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, and its center tracked just south of the Ninoy Aquino International Airport
Ninoy Aquino International Airport
The Ninoy Aquino International Airport or NAIA , also known as Manila International Airport , is the airport serving the general area of Manila and its surrounding metropolitan area...
.
Dan crossed over the island and emerged into the South China Sea
South China Sea
The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around...
, having lost its eye feature and weakened back into a tropical storm. Convection soon redeveloped as the storm moved northwestward through warm waters. The JTWC reports that Dan reattained typhoon status at 0000 UTC on October 12, although it according to the JMA it did so 24 hours earlier. The typhoon continued to intensify, and the JTWC estimates that it reached its peak intensity at 0600 UTC, with 1-minute maximum sustained winds of 130 km/h (80 mph). The JMA indicates that Dan peaked slightly afterward, with 10-minute sustained winds of 140 km/h (85 mph) and a minimum barometric pressure reading of 960 millibars.
The storm passed about 70 mi (112.7 km) south of Hainan Island and weakened somewhat. Increased wind shear further deteroirated the system as it approached the coast of Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
. The storm moved inland at around 1200 UTC on October 13, at which point the JMA downgraded it to a severe tropical storm and the JTWC issued their final advisory on the disturbance. The circulation ultimately dissipated over the mountainous terrain and its remnants continued to move westward into Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
.
Impact
Although it was relatively weak, the storm caused severe damage. In the Philippines, 58 fatalities from the cyclone were reported, with an additional 121 injuries. In total, 682,699 people, or 135,245 families, were affected by the typhoon, and 49,972 houses sustained damage. Monetary storm damage is placed at ₱1.4 billion PHPPhilippine peso
The peso is the currency of the Philippines. It is subdivided into 100 centavos . Before 1967, the language used on the banknotes and coins was English and so "peso" was the name used...
($30.10700 USD). The storm triggered flooding and landslides, while high winds brought down trees and powerlines. The second typhoon to strike the country within a week, Dan forced schools and government offices to close. Approximately 250,000 people were left homeless, and dozens of fishermen went missing offshore. In the Manila
Manila
Manila is the capital of the Philippines. It is one of the sixteen cities forming Metro Manila.Manila is located on the eastern shores of Manila Bay and is bordered by Navotas and Caloocan to the north, Quezon City to the northeast, San Juan and Mandaluyong to the east, Makati on the southeast,...
area, near-total power loss was reported. President Corazon Aquino
Corazon Aquino
Maria Corazon Sumulong Cojuangco-Aquino was the 11th President of the Philippines and the first woman to hold that office in Philippine history. She is best remembered for leading the 1986 People Power Revolution, which toppled Ferdinand Marcos and restored democracy in the Philippines...
issued a "state of calamity" there and in surrounding areas. As the storm progressed westward, it buffeted Hainan Island with gale-force winds.
Damage in Vietnam was also extensive. The typhoon flooded about 230000 acre (93,077.8 ha) of land and brought down utility lines. The high winds, reportedly blowing at 75 mph (120.7 km/h), ripped roofs off houses. Large storm tide
Storm tide
A storm tide is a tide with a high flood period caused by a storm. Storm tides can be a severe danger to the coast and the people living along the coast. The water level can rise to more than 5 meters above the normal tide....
s along the coast pushed flood waters ashore. The storm killed seven people in the country.