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Tropical Storm Lester (2004)
Encyclopedia
Tropical Storm Lester was a weak tropical storm that paralleled the Mexican coastline in October 2004. The 16th tropical cyclone
and 12th named storm of the 2004 Pacific hurricane season
, Lester originated from an area of disturbed weather that persisted southwest of the Gulf of Tehuantepec
. After organizing, the system was designated as a tropical depression on October 11. The depression was upgraded to a tropical storm the next day, and moved northwestward, just off the Mexican coastline. Due to the interaction with land among other factors, the storm degenerated on October 13. The storm dropped locally heavy rainfall, which caused minor flooding and mudslides. No fatalities or significant damage were reported.
. Later that day, a surface low pressure system
developed, and convection
began to organize into slightly curved bands. The disturbance continued to in this manner, and at 1800 UTC on October 11, the low level circulation had become sufficiently organized to be designated as a tropical depression. At the time, the depression consisted of a well-defined circulation, with some deep thunderstorm activity. Despite weak steering currents, the system started what was initially thought to be a westward drift, though just a few hours later was found to be towards the northwest. A small cyclone, a burst of deep convection formed at around the same time, and was said could have produced tropical storm-force winds.
Continuing its slow, northwestward track under the weal steering currents of a weak mid-level ridge
to its north, and a broad cyclonic circulation to its southwest, it was upgraded to Tropical Storm Lester at 1800 UTC on October 12. Originally, it was unclear whether the center of circulation would remain slightly offshore, or move inland. Due to the presence of a weak upper-level anticyclone that was centered just east of the system, favorable atmospheric conditions for strengthening prevailed, and the storm reached its peak intensity with winds of 50 mph (80.5 km/h) about 6–12 hours after being upgraded to a tropical storm. Early on October 13, radar imagery from Acapulco, Mexico indicated that Lester remained a small and well-organized cyclone as it passed just offshore. At the same time, light southwesterly wind shear
began to develop. The interaction with land, combined with influence from the low to the southwest, started to weaken the storm, and it was downgraded to a tropical depression at 1200 UTC on October 13. By later that day, reports from an Air Force Reserve Unit Hurricane Hunter Aircraft indicated that the cyclone had degenerated into a trough
on the northeastern side of the larger low to the southwest.
for the coast between Punta Maldonado to Zihuatanejo
. It was upgraded to a warning later that day. It was extended to Lázaro Cárdenas
on October 13. Later that day, the warning was lifted when Lester dissipated. Lester brought rains to parts of Oaxaca
and Guerrero
, reaching 3 to 5 in (76.2 to 127 mm). The highest 24-hour total peaked at 106.5 mm (4.2 in), recorded on October 12. Localized flooding was likely caused by the storm, though no reports of deaths were received by the National Hurricane Center
. However, the storm capsized two ships, and washed two more ashore. The heavy rain caused mudslides, which buried one man in his home; he was later rescued by his family. In and around the port of Acapulco, about 14 trees were downed, and minor pooling of water was reported.
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...
and 12th named storm of the 2004 Pacific hurricane season
2004 Pacific hurricane season
The 2004 Pacific hurricane season officially started on May 15, 2004 in the eastern Pacific, and on June 1, 2004 in the central Pacific, and lasted until November 30, 2004...
, Lester originated from an area of disturbed weather that persisted southwest of the Gulf of Tehuantepec
Gulf of Tehuantepec
Gulf of Tehuantepec is a large body of water on the Pacific coast of the Isthmus of Tehuantepec, southeastern Mexico, at . Most of the hurricanes that form in the Eastern Pacific organize in or near this body of water...
. After organizing, the system was designated as a tropical depression on October 11. The depression was upgraded to a tropical storm the next day, and moved northwestward, just off the Mexican coastline. Due to the interaction with land among other factors, the storm degenerated on October 13. The storm dropped locally heavy rainfall, which caused minor flooding and mudslides. No fatalities or significant damage were reported.
Meteorological history
By October 10, 2004, an area of disturbed weather was situated well to the southwest of the Gulf of TehuantepecGulf of Tehuantepec
Gulf of Tehuantepec is a large body of water on the Pacific coast of the Isthmus of Tehuantepec, southeastern Mexico, at . Most of the hurricanes that form in the Eastern Pacific organize in or near this body of water...
. Later that day, a surface low pressure system
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...
developed, and 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...
began to organize into slightly curved bands. The disturbance continued to in this manner, and at 1800 UTC on October 11, the low level circulation had become sufficiently organized to be designated as a tropical depression. At the time, the depression consisted of a well-defined circulation, with some deep thunderstorm activity. Despite weak steering currents, the system started what was initially thought to be a westward drift, though just a few hours later was found to be towards the northwest. A small cyclone, a burst of deep convection formed at around the same time, and was said could have produced tropical storm-force winds.
Continuing its slow, northwestward track under the weal steering currents of a weak mid-level 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 its north, and a broad cyclonic circulation to its southwest, it was upgraded to Tropical Storm Lester at 1800 UTC on October 12. Originally, it was unclear whether the center of circulation would remain slightly offshore, or move inland. Due to the presence of a weak upper-level anticyclone that was centered just east of the system, favorable atmospheric conditions for strengthening prevailed, and the storm reached its peak intensity with winds of 50 mph (80.5 km/h) about 6–12 hours after being upgraded to a tropical storm. Early on October 13, radar imagery from Acapulco, Mexico indicated that Lester remained a small and well-organized cyclone as it passed just offshore. At the same time, light southwesterly 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...
began to develop. The interaction with land, combined with influence from the low to the southwest, started to weaken the storm, and it was downgraded to a tropical depression at 1200 UTC on October 13. By later that day, reports from an Air Force Reserve Unit Hurricane Hunter Aircraft indicated that the cyclone had degenerated into a 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...
on the northeastern side of the larger low to the southwest.
Preparations and impact
On October 12, in response to Lester, the Mexican government issued a tropical storm watchTropical 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 coast between Punta Maldonado to Zihuatanejo
Zihuatanejo
Zihuatanejo or Ixtapa-Zihuatanejo, is the fourth-largest city in the Mexican state of Guerrero. Politically the city belongs to the municipality of Zihuatanejo de Azueta in the western part of Guerrero, but both are commonly referred to as Zihuatanejo...
. It was upgraded to a warning later that day. It was extended to Lázaro Cárdenas
Lázaro Cárdenas, Michoacán
Lázaro Cárdenas is a port city that with its surrounding municipality is located in the southern part of the Mexican state of Michoacán. It was formerly known as Los Llanitos, but changed its name as a tribute to Lázaro Cárdenas del Río, a Michoacán-born politician who was president of Mexico from...
on October 13. Later that day, the warning was lifted when Lester dissipated. Lester brought rains to parts of Oaxaca
Oaxaca
Oaxaca , , officially Estado Libre y Soberano de Oaxaca is one of the 31 states which, along with the Federal District, comprise the 32 federative entities of Mexico. It is divided into 571 municipalities; of which 418 are governed by the system of customs and traditions...
and 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....
, reaching 3 to 5 in (76.2 to 127 mm). The highest 24-hour total peaked at 106.5 mm (4.2 in), recorded on October 12. Localized flooding was likely caused by the storm, though no reports of deaths were received by 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...
. However, the storm capsized two ships, and washed two more ashore. The heavy rain caused mudslides, which buried one man in his home; he was later rescued by his family. In and around the port of Acapulco, about 14 trees were downed, and minor pooling of water was reported.
See also
- List of Pacific hurricanes
- Other East Pacific tropical storms
- Other tropical cyclones named Lester
- Timeline of the 2004 Pacific hurricane seasonTimeline of the 2004 Pacific hurricane seasonThe 2004 Pacific hurricane season had 17 tropical cyclones, of which 12 became named storms, 6 became hurricanes, and 3 became major hurricanes . This timeline documents all the storm formations, strengthening, weakening, landfalls, extratropical transitions, as well as dissipation...