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Hurricane Sergio (2006)
Encyclopedia
Hurricane Sergio was the second strongest Pacific hurricane
in the month of November on record, just after 2011's
Kenneth. The nineteenth named storm and eleventh hurricane of the 2006 Pacific hurricane season
, Sergio developed from a tropical wave
on November 13 about 460 miles (740 km) south of Manzanillo, Mexico
, and steadily intensified as it tracked southeastward. It reached peak winds of 110 mph (175 km/h) on November 15, and subsequently began to weaken due to increased wind shear
as it turned to the north. Sergio later turned to the west, remaining well off the coast of Mexico
, and dissipated on November 20 about 320 miles (515 km) west-northwest of it originally formed.
Sergio produced light rainfall along the coast of Mexico, though its effects were minimal. The formation of Sergio marked the 2006 season as the busiest in 12 years and the first season in which more than one tropical storm formed in November. Sergio, in addition to being the strongest hurricane after November 1, was also the longest-lived Pacific tropical cyclone
in November, lasting a total of seven days.
crossed Central America
and entered the eastern Pacific Ocean
on November 7. An area of convection along the wave tracked westward to the south of Central America and Mexico
, and became more concentrated on November 12 while located about 400 miles (645 km) south of Acapulco
. Later that day, Dvorak classification
began on the disturbance, and the convection continued to organize. Early on November 13, the National Hurricane Center
indicated the possibility of the system developing into a tropical depression. Thunderstorm activity briefly decreased, though late on November 13 the system acquired enough circulation and organized convection for it to be designated Tropical Depression Twenty-One-E while located about 460 miles (740 km) south of Manzanillo, Mexico
. Operationally, the depression was not upgraded until eleven hours later.
Initially, the tropical depression tracked to the northwest, and was forecast to peak as a 50 mph (80 km/h) tropical storm while continuing on a northwest motion. Located within an area of weak wind shear
, deep convection increased near the center, and banding feature
s became more pronounced. Anticyclonic flow
aloft and a moist troposphere allowed the depression to intensity into Tropical Storm Sergio on November 14. Shortly after becoming a tropical storm, Sergio turned to the southeast, believed to be due to the flow associated with a mid- to upper-level trough
to its northeast. It steadily intensified, and Sergio attained hurricane status on November 15 while located about 420 miles (675 km) southwest of Acapulco
. With a small, distinct eye
located in the center of the deep convection, Sergio rapidly intensified to attain peak winds of 110 mph (175 km/h) about 6 hours after becoming a hurricane.
Upon reaching peak strength, forecasters at the National Hurricane Center
predicted Hurricane Sergio to intensify further to reach winds of 120 mph (195 km/h). Shortly after peaking, the hurricane turned to the north and gradually weakened as wind shear from an upper-level trough to its northwest increased. By early on November 17, the low-cloud circulation became partially exposed on the west side of the deep convection, and it is estimated that Sergio weakened to a tropical storm later that day. A ridge
to its north and northeast turned the storm to the northwest and later to the west as Sergio gradually weakened. Deep convection reformed near the center on November 18, resulting in a slight increase in winds, though vertical shear quickly weakened it again. Later that day, the storm made its closest approach to land, about 225 miles (360 km) southwest of Michoacán
. Early on November 20 it degenerated into a tropical depression, and later that day Sergio dissipated
about 360 miles (580 km) southwest of Manzanillo, Mexico
, or about 320 miles (515 km) west-northwest of where it originally formed. The remnants of Sergio continued westward for about a day before the minimal amount of convection diminished.
were issued in relation to Sergio. Several storm advisories indicated a slight threat to coastal regions of Mexico
; the National Hurricane Center
assessed a 29% probability of tropical storm-force winds affecting Barra de Navidad
in Jalisco
. From November 16 and 17, the outer rainband
s of the hurricane dropped light precipitation along the Mexican coastline, peaking at 1.97 inches (50 mm) at Tierra Colorada
in Guerrero
.
Sergio contributed to November 2006 being the most active November since Pacific hurricane records began, based on using the accumulated cyclone energy
index. After Rosa formed a few days before Sergio, November 2006 became the first since 1966
to have more than one storm in the month. The hurricane was currently the second strongest in the month, as well as the longest-lasting.
Pacific hurricane
A Pacific hurricane or tropical storm is a tropical cyclone that develops in the northeastern part of the Pacific Ocean. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern, , central , and western...
in the month of November on record, just after 2011's
2011 Pacific hurricane season
The 2011 Pacific hurricane season is an ongoing, annual cycle of tropical cyclone formation. The season officially started on May 15, 2011, for the eastern Pacific, and started on June 1, 2011, for the central Pacific, both of which ended on November 30, 2011. These dates conventionally...
Kenneth. The nineteenth named storm and eleventh hurricane of the 2006 Pacific hurricane season
2006 Pacific hurricane season
The 2006 Pacific hurricane season was the most active Pacific hurricane season since 2000 producing 19 tropical storms or hurricanes. Eighteen developed within the National Hurricane Center area of warning responsibility, which is east of 140ºW, and one storm formed between 140ºW and the...
, Sergio developed from a 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...
on November 13 about 460 miles (740 km) south of Manzanillo, Mexico
Manzanillo, Colima
The name Manzanillo refers to the city as well as its surrounding municipality in the Mexican state of Colima. The city, located on the Pacific Ocean, contains Mexico's busiest port. Manzanillo was the third port created by the Spanish in the Pacific during the New Spain period...
, and steadily intensified as it tracked southeastward. It reached peak winds of 110 mph (175 km/h) on November 15, and subsequently began to weaken due to increased 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...
as it turned to the north. Sergio later turned to the west, remaining well off the coast of Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and dissipated on November 20 about 320 miles (515 km) west-northwest of it originally formed.
Sergio produced light rainfall along the coast of Mexico, though its effects were minimal. The formation of Sergio marked the 2006 season as the busiest in 12 years and the first season in which more than one tropical storm formed in November. Sergio, in addition to being the strongest hurricane after November 1, was also the longest-lived Pacific tropical cyclone
Pacific hurricane
A Pacific hurricane or tropical storm is a tropical cyclone that develops in the northeastern part of the Pacific Ocean. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern, , central , and western...
in November, lasting a total of seven days.
Meteorological history
A 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...
crossed 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 entered the eastern Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
on November 7. An area of convection along the wave tracked westward to the south of Central America and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and became more concentrated on November 12 while located about 400 miles (645 km) south of Acapulco
Acapulco
Acapulco is a city, municipality and major sea port in the state of Guerrero on the Pacific coast of Mexico, southwest from Mexico City. Acapulco is located on a deep, semi-circular bay and has been a port since the early colonial period of Mexico’s history...
. Later that day, Dvorak classification
Dvorak technique
The Dvorak technique is a widely used system to subjectively estimate tropical cyclone intensity based solely on visible and infrared satellite images. Several agencies issue Dvorak intensity numbers for cyclones of sufficient intensity...
began on the disturbance, and the convection continued to organize. Early on November 13, 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...
indicated the possibility of the system developing into a tropical depression. Thunderstorm activity briefly decreased, though late on November 13 the system acquired enough circulation and organized convection for it to be designated Tropical Depression Twenty-One-E while located about 460 miles (740 km) south of Manzanillo, Mexico
Manzanillo, Colima
The name Manzanillo refers to the city as well as its surrounding municipality in the Mexican state of Colima. The city, located on the Pacific Ocean, contains Mexico's busiest port. Manzanillo was the third port created by the Spanish in the Pacific during the New Spain period...
. Operationally, the depression was not upgraded until eleven hours later.
Initially, the tropical depression tracked to the northwest, and was forecast to peak as a 50 mph (80 km/h) tropical storm while continuing on a northwest motion. Located within an area of weak 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...
, deep convection increased near the center, and banding feature
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 became more pronounced. Anticyclonic flow
Anticyclone
An anticyclone is a weather phenomenon defined by the United States' National Weather Service's glossary as "[a] large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere"...
aloft and a moist troposphere allowed the depression to intensity into Tropical Storm Sergio on November 14. Shortly after becoming a tropical storm, Sergio turned to the southeast, believed to be due to the flow associated with a mid- to upper-level trough
Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure, often associated with fronts.Unlike fronts, there is not a universal symbol for a trough on a weather chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked...
to its northeast. It steadily intensified, and Sergio attained hurricane status on November 15 while located about 420 miles (675 km) southwest of Acapulco
Acapulco
Acapulco is a city, municipality and major sea port in the state of Guerrero on the Pacific coast of Mexico, southwest from Mexico City. Acapulco is located on a deep, semi-circular bay and has been a port since the early colonial period of Mexico’s history...
. With a small, distinct 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...
located in the center of the deep convection, Sergio rapidly intensified to attain peak winds of 110 mph (175 km/h) about 6 hours after becoming a hurricane.
Upon reaching peak strength, forecasters at 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...
predicted Hurricane Sergio to intensify further to reach winds of 120 mph (195 km/h). Shortly after peaking, the hurricane turned to the north and gradually weakened as wind shear from an upper-level trough to its northwest increased. By early on November 17, the low-cloud circulation became partially exposed on the west side of the deep convection, and it is estimated that Sergio weakened to a tropical storm later that day. A ridge
Ridge (meteorology)
A ridge is an elongated region of relatively high atmospheric pressure, the opposite of a trough....
to its north and northeast turned the storm to the northwest and later to the west as Sergio gradually weakened. Deep convection reformed near the center on November 18, resulting in a slight increase in winds, though vertical shear quickly weakened it again. Later that day, the storm made its closest approach to land, about 225 miles (360 km) southwest of Michoacán
Michoacán
Michoacán officially Estado Libre y Soberano de Michoacán de Ocampo is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 113 municipalities and its capital city is Morelia...
. Early on November 20 it degenerated into a tropical depression, and later that day Sergio dissipated
Dissipation
In physics, dissipation embodies the concept of a dynamical system where important mechanical models, such as waves or oscillations, lose energy over time, typically from friction or turbulence. The lost energy converts into heat, which raises the temperature of the system. Such systems are called...
about 360 miles (580 km) southwest of Manzanillo, Mexico
Manzanillo, Colima
The name Manzanillo refers to the city as well as its surrounding municipality in the Mexican state of Colima. The city, located on the Pacific Ocean, contains Mexico's busiest port. Manzanillo was the third port created by the Spanish in the Pacific during the New Spain period...
, or about 320 miles (515 km) west-northwest of where it originally formed. The remnants of Sergio continued westward for about a day before the minimal amount of convection diminished.
Impact and records
No tropical cyclone warnings or watchesTropical cyclone warnings and watches
Warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate...
were issued in relation to Sergio. Several storm advisories indicated a slight threat to coastal regions of Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
; 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...
assessed a 29% probability of tropical storm-force winds affecting Barra de Navidad
Barra de Navidad
Barra de Navidad is a small town located on the western coast-line of the Mexican state of Jalisco.The town of Barra de Navidad with a population of 7000+ is a small farming and fishing community located on the east end of the Bahía de Navidad, 60 km north of Manzanillo...
in Jalisco
Jalisco
Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...
. From November 16 and 17, the 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 of the hurricane dropped light precipitation along the Mexican coastline, peaking at 1.97 inches (50 mm) at Tierra Colorada
Tierra Colorada
Tierra Colorada is a city and seat of the municipality of Juan R. Escudero, in the state of Guerrero, south-western Mexico....
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....
.
Sergio contributed to November 2006 being the most active November since Pacific hurricane records began, based on using the accumulated cyclone energy
Accumulated cyclone energy
Accumulated cyclone energy is a measure used by the National Oceanic and Atmospheric Administration to express the activity of individual tropical cyclones and entire tropical cyclone seasons, particularly the North Atlantic hurricane season. It uses an approximation of the energy used by a...
index. After Rosa formed a few days before Sergio, November 2006 became the first since 1966
1966 Pacific hurricane season
The 1966 Pacific hurricane season started on May 15, 1966 and ended November 30, 1966. The season was of little note. Hurricane Blanca traveled 4,300 miles, setting a new record. During September and October of the year, Hurricane Helga and Tropical Storms Kirsten, Lorraine, and Maggie hitting Mexico...
to have more than one storm in the month. The hurricane was currently the second strongest in the month, as well as the longest-lasting.
See also
- List of Pacific hurricanes
- Timeline of the 2006 Pacific hurricane seasonTimeline of the 2006 Pacific hurricane seasonThe 2006 Pacific hurricane season was the most active since the 2000 season, producing produced 21 tropical depressions; 19 of which became tropical storms or hurricanes...
- List of storms in the 2006 Pacific hurricane season
External links
- The NHC's archive on Hurricane Sergio.