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Hurricane Ileana (2006)
Encyclopedia
Hurricane Ileana was the fourth of six major hurricanes
in the 2006 Pacific hurricane season
. Forming from a tropical wave
on August 21, Ileana tracked northwestward off the coast of Mexico throughout its duration. With favorable conditions for intensification, Ileana reached peak winds of 120 mph (195 km/h) within 48 hours of forming. Near peak intensity it passed near Socorro Island
, and subsequently began to weaken due to cooler waters. On August 27 Ileana weakened to a remnant low
, which dissipated two days later. The hurricane produced heavy rainfall along the Mexican coastline, causing flooding, and one person was killed due to strong waves.
moved off the coast of Africa on August 8, which subsequently tracked westward across the Atlantic Ocean with minimal convection. The wave crossed into the eastern Pacific Ocean on August 16, at which time convection increased along the wave axis. Three days later, a weak low pressure area
formed along the wave, and early on August 20 some broad cyclonic turning was evident within the cloud pattern. Gradually, banding features developed around the area of deep convection, and the system was expect to develop
further as it moved into an increasingly favorable environment. Convection increased late on August 20, although it initially remained disorganized; however, the thunderstorms consolidated near the low, and it is estimated the system developed into a tropical depression by 1200 UTC
on August 21, about 350 mi (560 km) south-southwest of Acapulco, Mexico.
A mid-level ridge
over Mexico caused the cyclone to track steadily northwestward. With warm water temperatures
and low vertical wind shear
, the depression quickly intensified into Tropical Storm Ileana. Convection developed and organized into a central dense overcast
, and with abundant low-level moisture, rapid deepening
was expected. An eye
formed in the center of the convection, and Ileana attained hurricane status late on August 22. On August 23, about 48 hours after forming, Ileana reached major hurricane
status and a peak intensity of 120 mph (195 km/h) about 60 mi (100 km) southeast of Socorro Island
. It also attained an atmospheric pressure
of 955 mbar
, as well as an eye diameter of 23 mi (37 km).
Initially, Ileana was forecast to intensify further to reach Category 4 status on the Saffir-Simpson scale
. After passing south of Socorro Island, the hurricane began a slow weakening trend due to cooler waters; as the winds decreased, the eye expanded and the thunderstorms waned. The ridge to its north weakened, causing the storm to slow and turn more to the west-northwest. Early on August 26, Ileana weakened to tropical storm status. Later that day, convection decreased markedly, and early on August 27 it deteriorated to tropical depression status. By late on August 27, Ileana had been without deep convection for about 18 hours, and so degenerated into a broad remnant low
. It continued slowly westward, dissipating on August 29 about 830 mi (1340 km) west-northwest of Cabo San Lucas
.
for the storm. While near peak intensity, it passed 60 mi (100 km) south of the unpopulated Socorro Island
; a station on the island recorded sustained winds of 59 mph (95 km/h), with gusts to 77 mph (125 km/h). The hurricane dropped heavy rainfall along the Mexican coastline, causing flooding in Nayarit
, Jalisco
, Colima
, Michoacán
, and Baja California Sur
. High surf from Ileana reached the coast, killing one man near Cabo San Lucas despite warnings not to swim in the ocean.
Tropical cyclone scales
Tropical systems are officially ranked on one of several tropical cyclone scales according to their maximum sustained winds and in what oceanic basin they are located...
in 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...
. Forming 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 August 21, Ileana tracked northwestward off the coast of Mexico throughout its duration. With favorable conditions for intensification, Ileana reached peak winds of 120 mph (195 km/h) within 48 hours of forming. Near peak intensity it passed near Socorro Island
Socorro Island
Socorro Island is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying some 600 kilometers off the country's western coast at 18°48'N, 110°59'W. The size is 16.5 by 11.5 km, with an area of 132 km².- Geology :...
, and subsequently began to weaken due to cooler waters. On August 27 Ileana weakened to a remnant low
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...
, which dissipated two days later. The hurricane produced heavy rainfall along the Mexican coastline, causing flooding, and one person was killed due to strong waves.
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...
moved off the coast of Africa on August 8, which subsequently tracked westward across the Atlantic Ocean with minimal convection. The wave crossed into the eastern Pacific Ocean on August 16, at which time convection increased along the wave axis. Three days later, a weak low pressure area
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...
formed along the wave, and early on August 20 some broad cyclonic turning was evident within the cloud pattern. Gradually, banding features developed around the area of deep convection, and the system was expect to develop
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...
further as it moved into an increasingly favorable environment. Convection increased late on August 20, although it initially remained disorganized; however, the thunderstorms consolidated near the low, and it is estimated the system developed into a tropical depression by 1200 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
on August 21, about 350 mi (560 km) south-southwest of Acapulco, Mexico.
A mid-level ridge
Ridge (meteorology)
A ridge is an elongated region of relatively high atmospheric pressure, the opposite of a trough....
over Mexico caused the cyclone to track steadily northwestward. With warm water temperatures
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...
and low vertical 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...
, the depression quickly intensified into Tropical Storm Ileana. Convection developed and organized into a central dense overcast
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...
, and with abundant low-level moisture, rapid deepening
Rapid deepening
Rapid deepening, also known as rapid intensification, is a meteorological condition that occurs when the minimum sea-level atmospheric pressure of a tropical cyclone decreases drastically in a short period of time. The National Weather Service describes rapid deepening as a decrease of...
was expected. 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...
formed in the center of the convection, and Ileana attained hurricane status late on August 22. On August 23, about 48 hours after forming, Ileana reached major hurricane
Tropical cyclone scales
Tropical systems are officially ranked on one of several tropical cyclone scales according to their maximum sustained winds and in what oceanic basin they are located...
status and a peak intensity of 120 mph (195 km/h) about 60 mi (100 km) southeast of Socorro Island
Socorro Island
Socorro Island is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying some 600 kilometers off the country's western coast at 18°48'N, 110°59'W. The size is 16.5 by 11.5 km, with an area of 132 km².- Geology :...
. It also attained an atmospheric pressure
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...
of 955 mbar
Bar (unit)
The bar is a unit of pressure equal to 100 kilopascals, and roughly equal to the atmospheric pressure on Earth at sea level. Other units derived from the bar are the megabar , kilobar , decibar , centibar , and millibar...
, as well as an eye diameter of 23 mi (37 km).
Initially, Ileana was forecast to intensify further to reach Category 4 status on the Saffir-Simpson scale
Saffir-Simpson Hurricane Scale
The Saffir–Simpson Hurricane Scale , or the Saffir–Simpson Hurricane Wind Scale , classifies hurricanes — Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms — into five categories distinguished by the intensities of their sustained winds...
. After passing south of Socorro Island, the hurricane began a slow weakening trend due to cooler waters; as the winds decreased, the eye expanded and the thunderstorms waned. The ridge to its north weakened, causing the storm to slow and turn more to the west-northwest. Early on August 26, Ileana weakened to tropical storm status. Later that day, convection decreased markedly, and early on August 27 it deteriorated to tropical depression status. By late on August 27, Ileana had been without deep convection for about 18 hours, and so degenerated into a broad remnant low
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...
. It continued slowly westward, dissipating on August 29 about 830 mi (1340 km) west-northwest of Cabo San Lucas
Cabo San Lucas
Cabo San Lucas , commonly called Cabo, is a city at the southern tip of the Baja California peninsula, in the municipality of Los Cabos in the Mexican state of Baja California Sur. As of the 2010 census, the population was 68,463 people...
.
Preparations and impact
Hurricane Ileana never significantly impacted land, and 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...
for the storm. While near peak intensity, it passed 60 mi (100 km) south of the unpopulated Socorro Island
Socorro Island
Socorro Island is a small volcanic island in the Revillagigedo Islands, a Mexican possession lying some 600 kilometers off the country's western coast at 18°48'N, 110°59'W. The size is 16.5 by 11.5 km, with an area of 132 km².- Geology :...
; a station on the island recorded sustained winds of 59 mph (95 km/h), with gusts to 77 mph (125 km/h). The hurricane dropped heavy rainfall along the Mexican coastline, causing flooding in Nayarit
Nayarit
Nayarit officially Estado Libre y Soberano de Nayarit is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 20 municipalities and its capital city is Tepic.It is located in Western Mexico...
, 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...
, Colima
Colima
Colima is one of the 31 states which, with the Federal District, make up the 32 Federal Entities of Mexico. It shares its name with its capital and main city, Colima....
, 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...
, and Baja California Sur
Baja California Sur
Baja California Sur , is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. Before becoming a state on October 8, 1974, the area was known as the South Territory of Baja California. It has an area of , or 3.57% of the land mass of Mexico and comprises...
. High surf from Ileana reached the coast, killing one man near Cabo San Lucas despite warnings not to swim in the ocean.
See also
- Other storms named Ileana
- 2006 Pacific hurricane season2006 Pacific hurricane seasonThe 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...
- List of Baja California 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 NHCNational Hurricane CenterThe 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...
's archive on Hurricane Ileana .