Tropical Storm Chanthu (2004)
Encyclopedia
Severe Tropical Storm Chanthu (International designation: 0405; JTWC
designation: 08W; PAGASA
: Gener) was a strong tropical storm that produced deadly flooding in Vietnam and Thailand. Originating from an area of low pressure
on June 5, 2004, Chanthu was first declared a tropical depression near southern Leyte Island
in the Philippines
. Tracking west-northwestward, the depression intensified into a tropical storm over the central Philippines before entering the South China Sea
. Once over the warm waters of the sea, the system quickly intensified, attaining its peak 10-minute winds of 110 km/h (70 mph) and 1-minute winds of 140 km/h (85 mph). On June 12, the storm made landfall
in Vietnam
before quickly weakening over land. By June 13, the system had weakened to a tropical depression and dissipated two days later.
In Vietnam, Chanthu wrought substantial damage and killed 38 people. Damage from the storm was estimated at 125 billion Vietnam dong ($7.9 million USD), mostly from agricultural losses. One person was also killed in Thailand.
associated with disorganized deep convective activity
located about 480 kilometres (300 mi) east-southeast of Yap
on June 5. Low wind shear
and weak diffluence allowed the system to gradually become organized; however, the following day, the Joint Typhoon Warning Center
(JTWC) ceased monitoring the system for potential development. By June 7, convection redeveloped around the low and the JTWC resumed monitoring the low; later in the day, the Japan Meteorological Agency
JMA, the Regional Specialized Meteorological Center
for the western Pacific basin
, classified it as a tropical depression. The same day, the depression entered the Area of Responsibility (AoR) of the Philippine Atmospheric, Geophysical and Astronomical Services Administration
and was given the local name Gener.
On June 8, the JTWC issued a Tropical Cyclone Formation Alert
for the system as they anticipated it to develop into a tropical storm within 24 hours. At 0000 UTC on June 9, the JTWC designated the depression as Tropical Storm 08W while located about 795 km (495 mi) southeast of Manila, Philippines. Several hours later, the storm made landfall on southern Leyte Island
with winds of 55 km/h (35 mph 10-minute winds) according to the JMA and 75 km/h (45 mph 1-minute winds) according to the JTWC. Rapidly tracking towards the west-northwest in response to a subtropical
ridge
to the north, the storm traversed the Philippine islands by June 10.
Late on June 10, the JMA upgraded the system to a tropical storm, at which time it received the name Chanthu; the name was contributed by Cambodia
and is a type of flower. Not long after being named, convection associated with the storm became displaced from the center of circulation
, leaving the low pressure center partially exposed. As Chanthu neared Vietnam, it tracked over warm sea surface temperature
s in the South China Sea
, allowing the storm to quickly intensify. Outflow
from the storm improved on June 11 and deep convection developed around the center of circulation. During a 12-hour span late on June 11 through early on June 12, the central barometric pressure of Chanthu dropped 15 hPa (mbar), falling to 975 hPa (mbar).
The maximum sustained wind
s also rose at this time; the JMA assessed the storm to have peaked with winds of 110 km/h (70 mph 10-minute winds) as a severe tropical storm; however, the JTWC assessed Chanthu to have peaked as a Category 1 typhoon on the Saffir–Simpson Hurricane Scale with winds of 140 km/h (85 mph 1-minute winds). Chanthu made landfall
around 1200 UTC on June 12 near Qui Nhon, Vietnam at this intensity. Due to the interaction with land, the storm rapidly weakened, with the JMA classifying it as a tropical depression early on June 13. The remnants of the storm persisted over Cambodia
until June 15 at which time it dissipated.
, producing moderate rainfall across several islands. The highest total was recorded at Roxas where 150.2 mm (5.9 in) of rain fell. In Vietnam, Chanthu dropped up to 238.9 mm (9.4 in), triggering flooding that killed 38 people. At least 180 homes were completely destroyed and numerous others were damaged. Tens of thousands of hectares of agricultural land was inundated by the storm. Damage from the storm were estimated at 125 billion VND ($7.9 million USD). In Thailand, the remnants of Chanthu produced widespread rainfall between June 13 and 16. Daily rainfall totals peaked at 216.7 mm (8.5 in) in Nan, Thailand
. Storm totals are not known but likely surpassed 400 mm (15.7 in). Throughout the country, only one person perished as a result of the storm.
Following the storm, the Government of Vietnam allocated 36 billion Vietnamese dong ($2 million USD) in recovery funds. Twenty of the fatalities were from one ship which went missing during the storm, on June 24, search attempts were called off. The families of the fishermen were each given 10 million VND ($560 USD) in cash and gifts by National Assembly Deputy Chairman Truong Quang Duoc.
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...
designation: 08W; PAGASA
Philippine Atmospheric, Geophysical and Astronomical Services Administration
The Philippine Atmospheric, Geophysical and Astronomical Services Administration is a Philippine national institution dedicated to provide flood and typhoon warnings, public weather forecasts and advisories, meteorological, astronomical, climatological, and other specialized information and...
: Gener) was a strong tropical storm that produced deadly flooding in Vietnam and Thailand. Originating from an area of low pressure
Low pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...
on June 5, 2004, Chanthu was first declared a tropical depression near southern Leyte Island
Leyte Island
Leyte is an island in the Visayas group of the Philippines.The island measures about 180 km north-south and about 65 km at its widest point. In the north it nearly joins Samar, separated by the San Juanico Strait, which becomes as narrow as 2 km in some places...
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...
. Tracking west-northwestward, the depression intensified into a tropical storm over the central Philippines before entering 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...
. Once over the warm waters of the sea, the system quickly intensified, attaining its peak 10-minute winds of 110 km/h (70 mph) and 1-minute winds of 140 km/h (85 mph). On June 12, the storm made landfall
Landfall (meteorology)
Landfall is the event of a tropical cyclone or a waterspout coming onto land after being over water. When a waterspout makes landfall it is reclassified as a tornado, which can then cause damage inland...
in 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 –...
before quickly weakening over land. By June 13, the system had weakened to a tropical depression and dissipated two days later.
In Vietnam, Chanthu wrought substantial damage and killed 38 people. Damage from the storm was estimated at 125 billion Vietnam dong ($7.9 million USD), mostly from agricultural losses. One person was also killed in Thailand.
Meteorological history
Severe Tropical Storm Chanthu originated out of a weak area of low pressureLow pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...
associated with disorganized deep convective activity
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 lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...
located about 480 kilometres (300 mi) east-southeast 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...
on June 5. Low 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...
and weak diffluence allowed the system to gradually become organized; however, the following day, 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) ceased monitoring the system for potential development. By June 7, convection redeveloped around the low and the JTWC resumed monitoring the low; later in the 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, the Regional Specialized Meteorological Center
Regional Specialized Meteorological Center
A Regional Specialized Meteorological Centre is responsible for the distribution of information, advisories, and warnings regarding the specific program they have a part of, agreed by consensus at the World Meteorological Organization as part of the World Weather Watch.-Tropical...
for the western Pacific basin
Pacific typhoon
A typhoon is a mature tropical cyclone that develops in the northwestern part of the Pacific Ocean between 180° and 100°E. This region is referred to as the northwest Pacific basin. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern , central , and...
, classified it as a tropical depression. The same day, the depression entered the Area of Responsibility (AoR) of the Philippine Atmospheric, Geophysical and Astronomical Services Administration
Philippine Atmospheric, Geophysical and Astronomical Services Administration
The Philippine Atmospheric, Geophysical and Astronomical Services Administration is a Philippine national institution dedicated to provide flood and typhoon warnings, public weather forecasts and advisories, meteorological, astronomical, climatological, and other specialized information and...
and was given the local name Gener.
On June 8, the JTWC issued a Tropical Cyclone Formation Alert
Tropical Cyclone Formation Alert
A Tropical Cyclone Formation Alert is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Naval Maritime Forecast Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone forming from a tropical disturbance that has been...
for the system as they anticipated it to develop into a tropical storm within 24 hours. At 0000 UTC on June 9, the JTWC designated the depression as Tropical Storm 08W while located about 795 km (495 mi) southeast of Manila, Philippines. Several hours later, the storm made landfall on southern Leyte Island
Leyte Island
Leyte is an island in the Visayas group of the Philippines.The island measures about 180 km north-south and about 65 km at its widest point. In the north it nearly joins Samar, separated by the San Juanico Strait, which becomes as narrow as 2 km in some places...
with winds of 55 km/h (35 mph 10-minute winds) according to the JMA and 75 km/h (45 mph 1-minute winds) according to the JTWC. Rapidly tracking towards the west-northwest in response to a subtropical
Subtropical cyclone
A subtropical cyclone is a weather system that has some characteristics of a tropical and an extratropical cyclone. As early as the 1950s, meteorologists were unclear whether they should be characterized as tropical or extratropical cyclones. They were officially recognized by the National...
ridge
High pressure area
A high-pressure area is a region where the atmospheric pressure at the surface of the planet is greater than its surrounding environment. Winds within high-pressure areas flow outward due to the higher density air near their center and friction with land...
to the north, the storm traversed the Philippine islands by June 10.
Late on June 10, the JMA upgraded the system to a tropical storm, at which time it received the name Chanthu; the name was contributed by Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
and is a type of flower. Not long after being named, convection associated with the storm became displaced from the center of circulation
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...
, leaving the low pressure center partially exposed. As Chanthu neared Vietnam, it tracked over warm sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
s in 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...
, allowing the storm to quickly intensify. 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...
from the storm improved on June 11 and deep convection developed around the center of circulation. During a 12-hour span late on June 11 through early on June 12, the central barometric pressure of Chanthu dropped 15 hPa (mbar), falling to 975 hPa (mbar).
The maximum sustained wind
Maximum sustained wind
The maximum sustained winds associated with a tropical cyclone are a common indicator of the intensity of the storm. Within a mature tropical cyclone, they are found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are...
s also rose at this time; the JMA assessed the storm to have peaked with winds of 110 km/h (70 mph 10-minute winds) as a severe tropical storm; however, the JTWC assessed Chanthu to have peaked as a Category 1 typhoon on the Saffir–Simpson Hurricane Scale with winds of 140 km/h (85 mph 1-minute winds). Chanthu made landfall
Landfall (meteorology)
Landfall is the event of a tropical cyclone or a waterspout coming onto land after being over water. When a waterspout makes landfall it is reclassified as a tornado, which can then cause damage inland...
around 1200 UTC on June 12 near Qui Nhon, Vietnam at this intensity. Due to the interaction with land, the storm rapidly weakened, with the JMA classifying it as a tropical depression early on June 13. The remnants of the storm persisted over Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
until June 15 at which time it dissipated.
Impact and aftermath
As a tropical storm, Chanthu passed through the PhilippinesPhilippines
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...
, producing moderate rainfall across several islands. The highest total was recorded at Roxas where 150.2 mm (5.9 in) of rain fell. In Vietnam, Chanthu dropped up to 238.9 mm (9.4 in), triggering flooding that killed 38 people. At least 180 homes were completely destroyed and numerous others were damaged. Tens of thousands of hectares of agricultural land was inundated by the storm. Damage from the storm were estimated at 125 billion VND ($7.9 million USD). In Thailand, the remnants of Chanthu produced widespread rainfall between June 13 and 16. Daily rainfall totals peaked at 216.7 mm (8.5 in) in Nan, Thailand
Nan, Thailand
Nan is a town in Northern Thailand. It is located some 668 km north of Bangkok. Its population exceeds 24.000. It is situated in the centre of the province which bears its name, and of which it is the administrative capital. It covers the whole tambon Nai Wiang of Mueang Nan district, an area...
. Storm totals are not known but likely surpassed 400 mm (15.7 in). Throughout the country, only one person perished as a result of the storm.
Following the storm, the Government of Vietnam allocated 36 billion Vietnamese dong ($2 million USD) in recovery funds. Twenty of the fatalities were from one ship which went missing during the storm, on June 24, search attempts were called off. The families of the fishermen were each given 10 million VND ($560 USD) in cash and gifts by National Assembly Deputy Chairman Truong Quang Duoc.