Tropical Storm Agatha (1992)
Encyclopedia
Tropical Storm Agatha was the deadliest tropical cyclone
to form during the 1992 Pacific hurricane season
. Developing as a tropical depression off the Pacific coast of Mexico
on June 1, the storm gradually organized over the next several hours. As it moved northward, the depression intensified into Tropical Storm Agatha later that day. After reaching its peak winds as a strong tropical storm, Agatha steadily weakened while turning to the west. The system was downgraded to a tropical depression on June 5, and subsequently lost its tropical characters the next day. Although Agatha never made landfall
, the storm's outer raindbands
triggered widespread flooding that killed ten people.
—or a quasi-equator
ward area of low pressure—moved off the Central America
n coast into the east Pacific. Over the subsequent days the system produced a broad area of convection
, which began to show sings of organization on May 29. Early on June 1, the disturbance became better defined, and shortly thereafter the National Hurricane Center
(NHC) classified it as a tropical depression while located 460 mi (740.3 km) southwest of Acapulco
. At the time, the depression maintained good outflow
aloft; it was forecast to strengthen into a minimal hurricane after three days. Based on a combination of ship data
and Dvorak
intensity estimates, the system was upgraded into Tropical Storm Agatha on June 2.
For the first two days of its duration, Agatha steered toward the north while embedded within a deep southerly flow. Steady intensification continued, and the storm reached winds of 50 mph (90 km/h) six hours after being upgraded as it neared the coast of Mexico
. By the afternoon of June 2, the center exhibited an elongated appearance within its associated central dense overcast, a large area of organized mid-tropospheric convection. Around 1800 UTC that same day, the storm peaked in intensity with winds of 70 mph (110 km/h) and a minimum pressure of 990 mbar (hPa; 29.23 inHg).
Maintaining its peak intensity for 30 hours, Agatha gradually decelerated as it passed within 100 mi (160.9 km) southwest of the Mexican coast. Although specialists at the NHC had anticipated a Category 1-hurricane landfall on the territory, the storm defied predictions and stayed at sea. The center of the storm promptly became ill-defined on infrared satellite imagery
, simultaneously recurving to the west. Agatha continued to degenerate quickly into the morning of June 4, with a ragged appearance observed on satellite imagery. By 0600 UTC June 5, the storm was downgraded back into tropical depression status prior to dissipating the next day.
anticipated Agatha to make landfall
in Mexico
near hurricane strength. In light of this, a tropical storm warning
and hurricane watch
were issued for the Pacific coast of Mexico
between Tenexpa to Cabo Corrites around 2100 UTC
that day. Additionally, heavy rains from the system prompted concerns over mudslides and flash flood
s. Following Agatha's turn towards the west early on June 3, the watches and warnings were discontinued. Roughly 1,500 people evacuated from coastal areas of Michoacan
due to the threat of damaging winds and flooding.
Although the center of Agatha remained offshore, heavy rains within the system's outer rainbands
impacted southwestern and central Mexico. Widespread flooding and mudslides killed ten people and left thousands homeless. Along the coast, waves reportedly reached heights of 16 ft (4.9 m).
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
to form during the 1992 Pacific hurricane season
1992 Pacific hurricane season
The 1992 Pacific hurricane season was the most active Pacific hurricane season on record. The most notable storm was Hurricane Iniki, which caused billions of dollars of damage to the Hawaiian Islands. Hurricanes Lester, Virgil, Winifred, and Orlene also made landfall and killed several people, but...
. Developing as a tropical depression off the Pacific 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...
on June 1, the storm gradually organized over the next several hours. As it moved northward, the depression intensified into Tropical Storm Agatha later that day. After reaching its peak winds as a strong tropical storm, Agatha steadily weakened while turning to the west. The system was downgraded to a tropical depression on June 5, and subsequently lost its tropical characters the next day. Although Agatha never 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...
, the storm's outer raindbands
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...
triggered widespread flooding that killed ten people.
Meteorological history
On May 26, 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...
—or a quasi-equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
ward area of low pressure—moved off the 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...
n coast into the east Pacific. Over the subsequent days the system produced a broad area of convection
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...
, which began to show sings of organization on May 29. Early on June 1, the disturbance became better defined, and shortly thereafter 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) classified it as a tropical depression while located 460 mi (740.3 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...
. At the time, the depression maintained good 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...
aloft; it was forecast to strengthen into a minimal hurricane after three days. Based on a combination of ship data
Weather ship
A weather ship was a ship stationed in the ocean as a platform for surface and upper air meteorological observations for use in weather forecasting. They were primarily located in the north Atlantic and north Pacific oceans, reporting via radio...
and Dvorak
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...
intensity estimates, the system was upgraded into Tropical Storm Agatha on June 2.
For the first two days of its duration, Agatha steered toward the north while embedded within a deep southerly flow. Steady intensification continued, and the storm reached winds of 50 mph (90 km/h) six hours after being upgraded as it neared 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...
. By the afternoon of June 2, the center exhibited an elongated appearance within its associated central dense overcast, a large area of organized mid-tropospheric convection. Around 1800 UTC that same day, the storm peaked in intensity with winds of 70 mph (110 km/h) and a minimum pressure of 990 mbar (hPa; 29.23 inHg).
Maintaining its peak intensity for 30 hours, Agatha gradually decelerated as it passed within 100 mi (160.9 km) southwest of the Mexican coast. Although specialists at the NHC had anticipated a Category 1-hurricane landfall on the territory, the storm defied predictions and stayed at sea. The center of the storm promptly became ill-defined on infrared satellite imagery
Satellite imagery
Satellite imagery consists of photographs of Earth or other planets made by means of artificial satellites.- History :The first images from space were taken on sub-orbital flights. The U.S-launched V-2 flight on October 24, 1946 took one image every 1.5 seconds...
, simultaneously recurving to the west. Agatha continued to degenerate quickly into the morning of June 4, with a ragged appearance observed on satellite imagery. By 0600 UTC June 5, the storm was downgraded back into tropical depression status prior to dissipating the next day.
Preparations and Impact
On June 2, forecasters at the National Hurricane CenterNational 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...
anticipated Agatha to make 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 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...
near hurricane strength. In light of this, a tropical storm warning
Tropical 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...
and hurricane watch
Tropical 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 for the Pacific coast of Mexico
Mexican Riviera
The Mexican Riviera refers collectively to twenty cities and lagoons lying on the western coast of Mexico. Although there are long distances between these cities, they are often referred to as the Mexican Riviera because of their popularity among tourists. Cruise ships often visit three or four of...
between Tenexpa to Cabo Corrites around 2100 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...
that day. Additionally, heavy rains from the system prompted concerns over mudslides and flash flood
Flash flood
A flash flood is a rapid flooding of geomorphic low-lying areas—washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a storm, hurricane, or tropical storm or meltwater from ice or snow flowing over ice sheets or snowfields...
s. Following Agatha's turn towards the west early on June 3, the watches and warnings were discontinued. Roughly 1,500 people evacuated from coastal areas of Michoacan
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...
due to the threat of damaging winds and flooding.
Although the center of Agatha remained offshore, heavy rains within the system's outer rainbands
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...
impacted southwestern and central Mexico. Widespread flooding and mudslides killed ten people and left thousands homeless. Along the coast, waves reportedly reached heights of 16 ft (4.9 m).
See also
- Other storms with the same nameHurricane AgathaThe name Agatha has been used for nine tropical cyclones in the Eastern Pacific Ocean.* Tropical Storm Agatha , stayed well away from land* Hurricane Agatha , made landfall in the Mexican state of Michoacán, causing moderate damage...
- 1992 Pacific hurricane season1992 Pacific hurricane seasonThe 1992 Pacific hurricane season was the most active Pacific hurricane season on record. The most notable storm was Hurricane Iniki, which caused billions of dollars of damage to the Hawaiian Islands. Hurricanes Lester, Virgil, Winifred, and Orlene also made landfall and killed several people, but...