The 1988 Pacific hurricane season was the least active Pacific hurricane season since 1981. It officially began May 15, in the eastern Pacific, and June 1, in the central Pacific and lasted until November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. The first named storm, Tropical Storm Aletta, formed on June 16, and the last-named storm, Tropical Storm Miriam, was previously named Hurricane Joan in the Atlantic Ocean before crossing Central America and re-emerging in the eastern Pacific; Miriam continued westward and dissipated on November 2.
The season produced 23 tropical depressions, of which 15 attained tropical storm status. Seven storms reached hurricane status, three of which became major hurricanes. The strongest storm of the season, Hurricane Hector, formed on July 30 to the south of Mexico and reached peak winds of 145 mph (233 km/h)—Category 4 status—before dissipating over open waters on August 9; Hector was never a threat to land. Tropical Storm Gilma was the only cyclone in the season to make landfall, crossing the Hawaiian Islands, although there were numerous near-misses. Gilma's Hawaiian landfall was unusual, but not unprecedented. There were also two systems that successfully crossed over from the Atlantic: the aforementioned Joan / Miriam and Hurricane Debby, which became Tropical Depression Seventeen-E, making the 1988 season the first on record in which more than one tropical cyclone has crossed between the Atlantic and Pacific basins intact. Three systems caused deaths: Tropical Storm Aletta caused one death in southwestern Mexico, Hurricane Uleki caused two drownings off the coast of Oahu as it passed by the Hawaiian Islands, and Hurricane Kristy caused 21 deaths in the Mexican states of Oaxaca and Chiapas.
Seasonal summary
The accumulated cyclone energy (ACE) index for the 1988 Pacific hurricane season was 127.45 units (87.79 units from the Eastern Pacific and 39.66 units from the Central Pacific).
The total tropical activity in the season was below-average. There were 13 cyclones in the Eastern Pacific, as well as two in the Central. Of the 15 cyclones, one crossed from the Atlantic Ocean into the Pacific, and another moved from the Central Pacific to the Western Pacific. In the Eastern Pacific, there were seven cyclones peaking as a tropical storm, and six hurricanes, of which two reached Category 3 intensity or higher on the Saffir–Simpson scale. A tropical storm and a major hurricane occurred in the Central Pacific.
Tropical Storm Gilma made the only landfalls of the season in the Hawaiian Islands, causing some rainfall, but no direct deaths or damage occurred as a result of it. These were the only landfalls in the season that were made, which is unusual as most landfalls in the Eastern Pacific occur on the Mexican coast. This is due to the closeness of the Mexican region to the major source of tropical activity to the west of Central America. Hurricane Uleki, the strongest hurricane in the Central Pacific region during the season, caused two drownings in Oahu and heavy waves hit the coast of the Hawaiian Islands. Tropical Storm Miriam, the last storm of the season, formed as a result of Hurricane Joan from the Atlantic, and flooding resulted in parts of Central America, due to heavy rainfall.
Systems
Tropical Depression One-E
A tropical disturbance organized into the first eastern Pacific tropical depression of the season on June 15. A convective band on the north and west sides of the system became well-defined, and anticyclonic outflow allowed for initial organization. After forming, the depression tracked west-southwestward and intensified due to disrupted outflow from a large air stream disturbance. On June 16, strong convection with spiral banding developed over the depression, although it failed to strengthen further. A low-pressure l northwest of the depression in combination with Tropical Storm Aletta to the northeast caused the depression to weaken, and it dissipated on June 18.
Tropical Storm Aletta
A tropical wave moved off the coast of Africa and progressed westward through the Atlantic Ocean and Caribbean, before crossing over Central America on June 13 and emerging into the warm waters of the east Pacific on June 14. Shortly after, satellite imagery showed good upper-level outflow, although cloud banding remained disorganized. On June 16, the broad circulation better organized on the northeastern section, with deep convection developing. A tropical depression formed later that day about 200 miles (320 km) to the southeast of Acapulco, Mexico. It developed further as it moved northward toward the southwest coast of Mexico, and had organized sufficiently to be named Tropical Storm Aletta on June 17. The cyclone drifted north-northwest for the next 36 hours before turning westward, parallel to the Mexican coast. The storm began to lose its convection on June 19 and weakened into a tropical depression later that day. The depression weakened further into a weak low-level circulation before dissipating on June 21. Although Aletta approached the Acapulco area of the Mexican coast, it did not make landfall.
The portion of coast affected by Aletta received heavy rainfall; unofficial reports state that one person died as a result of the storm, and the storm produced some damage due to rainfall and flooding.
Tropical Storm Bud
Satellite imagery first detected a low-level circulation on June 20, associated with some heavy convection, 200 miles (320 km) south of the Mexico–Guatemala border, and it intensified into a tropical depression. The cyclone moved northwest then west-northwest over two days. A 40 mph (64 km/h) wind report from a ship on June 21 allowed the depression to be upgraded to Tropical Storm Bud later that day. For the next day, the low-level circulation moved away from its deep convection, dissipating near Acapulco, Mexico. A portion of Bud remaining over land may have been part of the reason for the lack of strengthening of the cyclone.
Tropical Depression Four-E
A system developed in the eastern Pacific, and later strengthened into a tropical depression on July 1, when it obtained a better defined low-level circulation. The center was exposed, with little convection on the northeast side, due to shear aloft. The system moved to the northwest, while shear continued to move the deep convection of the cyclone to the southwest of its center of circulation. The circulation completely lacked deep convection late on July 2, although it continued to have a well-defined low-level center.
The depression drifted slowly northward, located south of Baja California, before dissipating just south of the peninsula on July 4, with no circulation or deep convection detected. A small amount of associated rainfall affected Baja California, as the cyclone passed near the peninsula.
Hurricane Carlotta
A tropical wave moved off the western coast of Africa on June 23, and for the next two weeks, moved through the tropical waters of the Atlantic Ocean and later crossed Central America. It began developing further when it entered the Pacific Ocean and became a dense area of moisture and cloudiness. The wave developed into a disturbance on July 8, and attained tropical depression status in the afternoon on July 8, south of Mexico. After entering a favorable area of warm waters, the depression strengthened to Tropical Storm Carlotta on July 9. Carlotta continued to develop, reached peak strength, and developed into Hurricane Carlotta on July 11. During the duration of the storm, Carlotta was not considered a hurricane, however after post-season reanalysis Carlotta's strength was upgraded to minimal hurricane status. As it moved into less favorable conditions it lost strength and weakened to a tropical storm on July 12. Carlotta began to lose its deep convection, and weakened into a tropical depression on July 13 as it moved into cooler waters. It later moved west-southwest and dissipated on July 15.
Tropical Storm Daniel
A tropical wave moved off the coast of northwestern Africa on July 4, and moved through tropical regions of the northern Atlantic and Caribbean without the indication of development. The tropical disturbance crossed Central America on July 14, and from then until July 18, the westward motion decreased, as convection and organization increased over warm waters. It developed into a tropical depression on July 19, and into Tropical Storm Daniel 600 miles (970 km) southwest of the southern tip of Baja California on July 20. A high pressure system over the western United States and northern Mexico forced Daniel and an upper-level low on parallel west-northwest paths. Daniel stayed generally the same strength for the next few days, reaching peak strength on July 23. Daniel declined into a tropical depression on July 25 and dissipated on July 26.
Tropical Storm Emilia
On July 15, a tropical wave exited Africa and crossed the Atlantic Ocean. It crossed into the Pacific Ocean on July 24, developing convection and outflow. On July 27, it organized into a tropical depression off the southwest coast of Mexico. Continuing generally westward, the thunderstorm activity fluctuated, and slowly developing, it intensified into Tropical Storm Emilia on July 29. The storm attained peak winds of 70 mph (110 km/h) on July 30, although wind shear and interaction with nearby Tropical Storm Fabio prevented further intensification; the low-level circulation was located along the northwest edge of the deepest convection. It became disorganized and difficult to locate on satellite imagery, and soon the circulation was exposed from the thunderstorms. On August 1, Emilia weakened to tropical depression status, and late on August 2, the last advisory was issued as the system had become very disorganized with minimal convection. Its remnants were tracked for the next few days, and although some deep convection returned momentarily, the system's convection soon disappeared.
Hurricane Fabio
A well-organized ITCZ disturbance with deep convection organized further over the northeastern Pacific Ocean on July 28. It developed into a tropical depression later that day, while 1,000 miles (1,600 km) southwest of the southern tip of Baja California. The position of Fabio's formation was much further south and west than where most tropical cyclones form during the same time period. The depression moved westward while gradually strengthening and it developed into Tropical Storm Fabio on July 29. It intensified further over the next few days and it intensified into a hurricane on July 31. The system increased its speed as it steadily strengthened further. A trough turned the storm west-northwestward on August 3. Satellite estimates indicated that Fabio reached its maximum intensity later on August 3, with a well-defined eye with very deep convection surrounding it. The Central Pacific Hurricane Center issued a tropical storm watch for the Big Island on August 4, due to the threatening west-northwest turn towards it. However, the retreat of a trough later turned Fabio back to the west and the CPHC discontinued the tropical storm watch on August 5. Fabio's good upper-level conditions later weakened and began to lose its convection over cooler waters. Fabio quickly weakened and it weakened into a tropical storm again later on August 5, and back to a depression on August 6. The depression turned west-northwestward again on August 8, but Fabio dissipated on August 9. As the cyclone moved near the Hawaiian islands, heavy rainfall fell across the chain, peaking at 18.75 in (476 mm) near Pāpa'ikou on the island of Hawaii.
Tropical Depression Nine-E
A tropical depression developed in the eastern Pacific on July 28, forecast to be absorbed by a very close nearby depression, later Tropical Storm Gilma. The depression moved northward, although in unfavorable conditions.
The cyclone weakened as the depression to the southwest strengthened further. Limited deep convection developed with the system, although the cyclone continued in unfavorable conditions with shearing. Visible satellite imagery later showed a very weak system, and the storm dissipated on July 29.
Tropical Storm Gilma
A wave that previously moved through the Atlantic from the northwest coast of Africa, crossed over Central America into the Pacific on July 17 or July 18. On July 19, this disturbance was 700 miles (1,100 km) to the southeast of the developing Tropical Storm Daniel. The system moved westward for the following week without any signs of intensification. However, on July 26 and 27, the system appeared to be strengthening due to a banding pattern. By July 28, the convection underwent further organization with some weak outflow high in the storm. It developed into a tropical depression later on July 28, much further west then most east Pacific storms develop at. For the next day the cyclone remained fairly stationary, but began to strengthen over warm waters. On July 29 the depression strengthened into Tropical Storm Gilma, based on satellite imagery. Limited intensification followed, due to shear high in the storm. It weakened a tropical depression again on July 30, due to weakness depicted in satellite imagery. Gilma then moved west-northwestward through the northeast Pacific. The depression skirted the Hawaiian Islands, but dissipated near Oahu on August 3. On the Hawaiian Islands there were no direct damage or deaths, although some rainfall occurred on the islands.