Tropical Storm Harvey (2011)
Encyclopedia
Tropical Storm Harvey was a tropical storm that formed and dissipated during the 2011 Atlantic hurricane season
. Harvey was also the last in a record-breaking string of eight consecutive storms that reached only tropical storm status. Hurricane Irene, the next storm to form after Harvey, reached hurricane status. Harvey developed from a westward-moving tropical wave
that emerged off the coast of Africa
. Once within an increasingly favorable environment over the Caribbean
, the wave began to exhibit patent signs of tropical development
, and it is estimated a tropical depression formed late on August 18. It continued to move over warm waters in the vicinity of Central America
, and later that day the cyclone deepened into Tropical Storm Harvey while remaining just offshore Honduras
. Subsequent favorable conditions allowed for additional organization, and during the afternoon of August 20 Harvey moved ashore in Belize
as a strong tropical storm.
that is estimated to have passed over Dakar, Senegal, at 0000 UTC on August 11, 2011. Several hours earlier, the National Hurricane Center
(NHC) had classified the system as an "invest
", which identified it as an area of interest for potential effects on future tropical weather. By the time it had emerged over the Atlantic Ocean, the wave was already accompanied by a weak center of low pressure and patches of moderate to strong convection. In response, the NHC noted the potential for the wave to gradually develop into a tropical cyclone. The wave continued toward the west at 15 to 20 mph (24.1 to 32.2 km/h), and despite initial concerns about more immediate tropical cyclogenesis
, the wave become less vigorous over the next several days; on August 13, the wave was described as inactive, with no strong shower or thunderstorm activity. Isolated pockets of convection redeveloped over the course of the following day, and while approaching the Lesser Antilles
on August 15, the system began to show signs of broad cyclonic
turning. Early the next day, the system was analyzed as an area of low pressure between Saint Lucia
and Saint Vincent
and an inverted trough extending well to the north, terminating well to the northeast of the Lesser Antilles.
The wave progressed westward through the Caribbean Sea
and produced areas of heavy showers and thunderstorms, although convection on the northern side of the system was limited, possibly a result of excessive Saharan dust. Mid-level cyclonic turning became more pronounced by the end of the day on August 16, and although a closed center of surface low pressure was still lacking, overall conditions were becoming more favorable for the potential development of a tropical system. With increasing confidence in the forecast continued maturation of the disturbance, the NHC issued a "high chance" of the wave becoming a tropical cyclone within 48 hours. By early on August 18, surface baromatric pressures
began to fall for the first time under the system, an indication that a surface low pressure center had begun to form. A low-level circulation pattern subsequently became identifiable, and the developing center of circulation was tentatively pinpointed roughly 100 mi (160.9 km) east-northeast of Cape Gracias a Dios. At 1800 UTC on August 18, the system was designated Tropical Depression Eight, with maximum sustained winds of 35 mph (56.3 km/h) and a minimum pressure of 1006 mb.
During the morning hours of August 19, Hurricane Hunters
aircraft investigated the depression, and found a well-defined center of circulation slightly northeast of where it was originally assumed to be. Observations from the flight yielded data that suggested the depression was only slightly below tropical storm status, and with the new center location, forecasts were adjusted to allow for more time over water. As a result, more intensification than previously expected was possible. Steered by a building high pressure area
over the Gulf of Mexico, the cyclone remained on its westward course, and was expected to move west-northwestward throughout its duration. Continuing to deepen, Tropical Depression Eight attained tropical storm status during the afternoon and was named Harvey in an intermediate advisory at 1800 UTC. Harvey continued to strengthen throughout the afternoon, with an improved appearance on visible satellite imagery and good outflow across the northwestern part of the storm. Harvey's remnants continued to move southwards, slowly. A few hours later, Harvey's remnants absorbed the same tropical wave that produced it, which was located just south of Mexico, in the Pacific Ocean. During the early afternoon of August 23, the remnants crossed over Mexico and emerged into the Pacific Ocean, where they were absorbed by a monsoon trough
.
. Precipitation totals commonly exceeded 2 to 3 in (50.8 to 76.2 mm), and across the mountains of the Basse-Terre
area, up to 10 in (254 mm) of rainfall was reported. Adverse conditions on the island began on August 15 and had mostly cleared by August 18, although residual shower activity remained possible throughout the day.
An intense thunderstorm embedded within the developing storm passed over Saint Croix on August 16, generating a brief period of strong winds and downpours. Rohlsen Airport recorded wind gusts as high as 47 mph (75.6 km/h); simultaneously, a sensor at Salt River Bay recorded a slightly higher gust of 50 mph (80.5 km/h). The strong winds brought down at least one large tree and resulted in minor power outages, although workers quickly arrived to repair the damage. Despite the issuance of an urban and small-stream flood advisory for the island, the thunderstorm's brevity prevented significant accumulations of precipitation. Under 0.5 in (12.7 mm) of rain fell on Saint Croix, while just a trace of precipitation was recorded in nearby Saint Thomas
.
The system brushed Puerto Rico
as it passed south, buffeting portions of the island with strong winds. Gusts reportedly reached 60 mph (96.6 km/h), although as is common with squally weather, sustained winds were much lower. One resident compared a 15-minute bout of particularly strong winds to the severity of a tornado, and some damage was reported. Scattered shower and thunderstorm activity also affected parts of the Dominican Republic
, where residents were warned of the potential for flash flooding and mudslides and for the potential for rivers to rise above their banks.
and the Atlantic coast of Guatemala
. Tropical storm warnings were issued for the coast of Belize
, the southeastern coast of the Yucatán Peninsula, and the Bay Islands Department of Honduras. A "yellow alert" was declared for five departments of Honduras: Gracias a Dios, Colón, Atlantida
, Cortés, and Islas de la Bahia. Two other departments, Yoro and Olancho. As a precautionary measure, shelters were prepared in case of an evacuation. As outer rainband
s began to drop heavy precipitation in parts of northern Guatemala
, authorities issued orange alerts for high-risk areas, with a yellow alert remaining in effect nationwide.
In Mexico, heavy rains from Harvey triggered several landslides, one of which killed three people. The most significant impact took place in Veracruz
where 334 homes were damaged by the storm. In Guerrero
, significant flooding damaged a bridge and isolated the town of Xaltianguis from surrounding areas. Heavy rains in Chiapas
caused several rivers to overflow their banks, causing moderate flooding in several towns and cities. Landslides associated with the system damaged 36 homes and affected three highways in the state.
2011 Atlantic hurricane season
The 2011 Atlantic hurricane season is tied for the third most active season on record with 1887, 1995 and 2010. It began on June 1, 2011, and ended on November 30, 2011, however these dates conventionally delimit the period of each year when most tropical cyclones develop in the Atlantic basin...
. Harvey was also the last in a record-breaking string of eight consecutive storms that reached only tropical storm status. Hurricane Irene, the next storm to form after Harvey, reached hurricane status. Harvey developed from a westward-moving tropical wave
Tropical wave
Tropical waves, easterly waves, or tropical easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of...
that emerged off the coast of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Once within an increasingly favorable environment over the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
, the wave began to exhibit patent signs of tropical development
Tropical cyclogenesis
Tropical cyclogenesis is the term that describes the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which mid-latitude cyclogenesis occurs...
, and it is estimated a tropical depression formed late on August 18. It continued to move over warm waters in the vicinity of Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
, and later that day the cyclone deepened into Tropical Storm Harvey while remaining just offshore Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
. Subsequent favorable conditions allowed for additional organization, and during the afternoon of August 20 Harvey moved ashore in Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
as a strong tropical storm.
Meteorological history
The origins of Tropical Storm Harvey trace back to a westward-moving Atlantic tropical waveTropical wave
Tropical waves, easterly waves, or tropical easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of...
that is estimated to have passed over Dakar, Senegal, at 0000 UTC on August 11, 2011. Several hours earlier, the National Hurricane Center
National Hurricane Center
The National Hurricane Center , located at Florida International University in Miami, Florida, is the division of the National Weather Service responsible for tracking and predicting weather systems within the tropics between the Prime Meridian and the 140th meridian west poleward to the 30th...
(NHC) had classified the system as an "invest
Invest (meteorology)
An invest in meteorology is a designated area of disturbed weather that is being monitored for tropical cyclone development. Invests are designated by three separate forecast centers: the National Hurricane Center, Central Pacific Hurricane Center and Joint Typhoon Warning Center...
", which identified it as an area of interest for potential effects on future tropical weather. By the time it had emerged over the Atlantic Ocean, the wave was already accompanied by a weak center of low pressure and patches of moderate to strong convection. In response, the NHC noted the potential for the wave to gradually develop into a tropical cyclone. The wave continued toward the west at 15 to 20 mph (24.1 to 32.2 km/h), and despite initial concerns about more immediate tropical cyclogenesis
Tropical cyclogenesis
Tropical cyclogenesis is the term that describes the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which mid-latitude cyclogenesis occurs...
, the wave become less vigorous over the next several days; on August 13, the wave was described as inactive, with no strong shower or thunderstorm activity. Isolated pockets of convection redeveloped over the course of the following day, and while approaching the Lesser Antilles
Lesser Antilles
The Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...
on August 15, the system began to show signs of broad cyclonic
Cyclone
In meteorology, a cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale...
turning. Early the next day, the system was analyzed as an area of low pressure between Saint Lucia
Saint Lucia
Saint Lucia is an island country in the eastern Caribbean Sea on the boundary with the Atlantic Ocean. Part of the Lesser Antilles, it is located north/northeast of the island of Saint Vincent, northwest of Barbados and south of Martinique. It covers a land area of 620 km2 and has an...
and Saint Vincent
Saint Vincent (island)
Saint Vincent is a volcanic island in the Caribbean. It is the largest island of the chain called Saint Vincent and the Grenadines. It is located in the Caribbean Sea, between Saint Lucia and Grenada. It is composed of partially submerged volcanic mountains...
and an inverted trough extending well to the north, terminating well to the northeast of the Lesser Antilles.
The wave progressed westward through the Caribbean Sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....
and produced areas of heavy showers and thunderstorms, although convection on the northern side of the system was limited, possibly a result of excessive Saharan dust. Mid-level cyclonic turning became more pronounced by the end of the day on August 16, and although a closed center of surface low pressure was still lacking, overall conditions were becoming more favorable for the potential development of a tropical system. With increasing confidence in the forecast continued maturation of the disturbance, the NHC issued a "high chance" of the wave becoming a tropical cyclone within 48 hours. By early on August 18, surface baromatric pressures
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
began to fall for the first time under the system, an indication that a surface low pressure center had begun to form. A low-level circulation pattern subsequently became identifiable, and the developing center of circulation was tentatively pinpointed roughly 100 mi (160.9 km) east-northeast of Cape Gracias a Dios. At 1800 UTC on August 18, the system was designated Tropical Depression Eight, with maximum sustained winds of 35 mph (56.3 km/h) and a minimum pressure of 1006 mb.
During the morning hours of August 19, Hurricane Hunters
Hurricane Hunters
The Hurricane Hunters are aircraft that fly into tropical cyclones in the North Atlantic Ocean and Northeastern Pacific Ocean for the specific purpose of directly measuring weather data in and around those storms. In the United States, the Air Force, Navy, and NOAA units have all participated in...
aircraft investigated the depression, and found a well-defined center of circulation slightly northeast of where it was originally assumed to be. Observations from the flight yielded data that suggested the depression was only slightly below tropical storm status, and with the new center location, forecasts were adjusted to allow for more time over water. As a result, more intensification than previously expected was possible. Steered by a building high pressure area
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...
over the Gulf of Mexico, the cyclone remained on its westward course, and was expected to move west-northwestward throughout its duration. Continuing to deepen, Tropical Depression Eight attained tropical storm status during the afternoon and was named Harvey in an intermediate advisory at 1800 UTC. Harvey continued to strengthen throughout the afternoon, with an improved appearance on visible satellite imagery and good outflow across the northwestern part of the storm. Harvey's remnants continued to move southwards, slowly. A few hours later, Harvey's remnants absorbed the same tropical wave that produced it, which was located just south of Mexico, in the Pacific Ocean. During the early afternoon of August 23, the remnants crossed over Mexico and emerged into the Pacific Ocean, where they were absorbed by a monsoon trough
Monsoon 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...
.
Caribbean Sea
Prior to becoming a tropical cyclone, Harvey's precursor disturbance produced squally conditions, including intermittent torrents and gusty winds, to much of the Lesser Antilles. Coinciding with the typical rainy season, which lasts from July to October and is characterized by frequent tropical waves, the wave triggered heavy rainfall on the island of GuadeloupeGuadeloupe
Guadeloupe is an archipelago located in the Leeward Islands, in the Lesser Antilles, with a land area of 1,628 square kilometres and a population of 400,000. It is the first overseas region of France, consisting of a single overseas department. As with the other overseas departments, Guadeloupe...
. Precipitation totals commonly exceeded 2 to 3 in (50.8 to 76.2 mm), and across the mountains of the Basse-Terre
Basse-Terre
Basse-Terre is the prefecture of Guadeloupe, an overseas region and department of France located in the Lesser Antilles...
area, up to 10 in (254 mm) of rainfall was reported. Adverse conditions on the island began on August 15 and had mostly cleared by August 18, although residual shower activity remained possible throughout the day.
An intense thunderstorm embedded within the developing storm passed over Saint Croix on August 16, generating a brief period of strong winds and downpours. Rohlsen Airport recorded wind gusts as high as 47 mph (75.6 km/h); simultaneously, a sensor at Salt River Bay recorded a slightly higher gust of 50 mph (80.5 km/h). The strong winds brought down at least one large tree and resulted in minor power outages, although workers quickly arrived to repair the damage. Despite the issuance of an urban and small-stream flood advisory for the island, the thunderstorm's brevity prevented significant accumulations of precipitation. Under 0.5 in (12.7 mm) of rain fell on Saint Croix, while just a trace of precipitation was recorded in nearby Saint Thomas
Saint Thomas, U.S. Virgin Islands
Saint Thomas is an island in the Caribbean Sea and with the islands of Saint John, Saint Croix, and Water Island a county and constituent district of the United States Virgin Islands , an unincorporated territory of the United States. Located on the island is the territorial capital and port of...
.
The system brushed Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
as it passed south, buffeting portions of the island with strong winds. Gusts reportedly reached 60 mph (96.6 km/h), although as is common with squally weather, sustained winds were much lower. One resident compared a 15-minute bout of particularly strong winds to the severity of a tornado, and some damage was reported. Scattered shower and thunderstorm activity also affected parts of the Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
, where residents were warned of the potential for flash flooding and mudslides and for the potential for rivers to rise above their banks.
Central America and Mexico
With the storm expected to continue on its westward track, tropical storm watches were posted for the northern coast of HondurasHonduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
and the Atlantic coast of Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
. Tropical storm warnings were issued for the coast of Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
, the southeastern coast of the Yucatán Peninsula, and the Bay Islands Department of Honduras. A "yellow alert" was declared for five departments of Honduras: Gracias a Dios, Colón, Atlantida
Atlántida (department)
Atlántida is a department located on the north Caribbean shore of Honduras, Central America. The capital is the port city of La Ceiba.In the past decades the tourism took over to become the most important legitimate economic source for the coastal area. In 2005 it had an estimated population of...
, Cortés, and Islas de la Bahia. Two other departments, Yoro and Olancho. As a precautionary measure, shelters were prepared in case of an evacuation. As outer rainband
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...
s began to drop heavy precipitation in parts of northern Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
, authorities issued orange alerts for high-risk areas, with a yellow alert remaining in effect nationwide.
In Mexico, heavy rains from Harvey triggered several landslides, one of which killed three people. The most significant impact took place in Veracruz
Veracruz
Veracruz, formally Veracruz de Ignacio de la Llave officially Estado Libre y Soberano de Veracruz de Ignacio de la Llave , is one of the 31 states that, along with the Federal District, comprise the 32 federative entities of Mexico. It is divided in 212 municipalities and its capital city is...
where 334 homes were damaged by the storm. In Guerrero
Guerrero
Guerrero officially Estado Libre y Soberano de Guerrero is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 81 municipalities and its capital city is Chilpancingo....
, significant flooding damaged a bridge and isolated the town of Xaltianguis from surrounding areas. Heavy rains in Chiapas
Chiapas
Chiapas officially Estado Libre y Soberano de Chiapas is one of the 31 states that, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 118 municipalities and its capital city is Tuxtla Gutierrez. Other important cites in Chiapas include San Cristóbal de las...
caused several rivers to overflow their banks, causing moderate flooding in several towns and cities. Landslides associated with the system damaged 36 homes and affected three highways in the state.
See also
- Hurricane DeanHurricane DeanThe name Dean was used for five tropical cyclones in the Northern Atlantic Ocean:*1983's Tropical Storm Dean, which struck the coast of Virginia, causing minor erosion and flooding...
- Hurricane RichardHurricane Richard (2010)Hurricane Richard was the seventeenth named storm and the tenth hurricane of the 2010 Atlantic hurricane season. Richard developed from an area of low pressure that stalled in the Caribbean Sea in mid-October...
- 2011 Atlantic hurricane season2011 Atlantic hurricane seasonThe 2011 Atlantic hurricane season is tied for the third most active season on record with 1887, 1995 and 2010. It began on June 1, 2011, and ended on November 30, 2011, however these dates conventionally delimit the period of each year when most tropical cyclones develop in the Atlantic basin...
- Other storms with the name
External links
- Advisory archive from the National Hurricane Center
- Latest satellite images from the National Environmental Satellite, Data, and Information Service