The 1997 Pacific hurricane season was a very active hurricane season. With hundreds of deaths and hundreds of millions of dollars in damage, this was one of the deadliest and costliest Pacific hurricane seasons on record. This was due to the exceptionally strong 1997–98 El Niño event. The season officially started on May 15, in the eastern Pacific, and on June 1, in the central Pacific, and lasted until November 30. These dates conventionally delimit the period of each year when almost all tropical cyclones form in the northeastern Pacific Ocean.

Several storms impacted land. The first was Tropical Storm Andres which killed four people and left another two missing. In August, Tropical Storm Ignacio took an unusual path through the basin, resulting in its extratropical remnants causing minimal damage throughout the Pacific Northwest and California. Linda became the most intense east Pacific hurricane in recorded history, a record it maintained until it was surpassed by Hurricane Patricia in 2015. Although it never made landfall, it produced large surf in Southern California and as a result, five people had to be rescued. Hurricane Nora caused flooding and damage in the Southwestern United States, while Olaf made two landfalls and caused eighteen deaths and several other people were reported missing. Hurricane Pauline killed several hundred people and caused record damage in southeastern Mexico. In addition, Super Typhoons Oliwa and Paka originated in the region before crossing the International Date Line and causing significant damage in the western Pacific. There were also two Category 5 hurricanes: Linda and Guillermo.

Activity in the season was above average. The season produced 17 named storms, which was a little above normal. The average number of named storms per year is 15. The 1997 season also had 9 hurricanes, compared to the average of 8. There were also 7 major hurricanes compared to the average of 4.

Season summary

The 1997 Pacific hurricane season officially started on May 15, 1997, in the Eastern Pacific, and on June 1, 1997, in the Central Pacific, and lasted until November 30, 1997. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean. The first storm, Andres, formed on June 1. The last storm, Paka, crossed the International Date Line into the Northwestern Pacific Basin on December 6.

The 1997 Pacific hurricane season was fairly active, due to the strong El Niño that was occurring at the time. El Niño causes wind shear to be reduced and water temperatures to increase, resulting in conditions more conductive for tropical cyclones in the East Pacific. There were 24 tropical cyclones in total, including five unnamed tropical depressions. Of the 19 remaining tropical cyclones that became tropical storms, nine reached hurricane status (excluding Tropical Storms Oliwa and Paka, which attained typhoon status after crossing into the Western Pacific basin). Also, seven of the nine hurricanes reached Category 3 intensity or higher on the Saffir–Simpson hurricane scale, becoming major hurricanes.

Activity in the Central Pacific was also above average. Two tropical storms formed, as did three tropical depressions. Four tropical cyclones also moved in from the Eastern Pacific. Overall, nine tropical cyclones entered or formed in the Central Pacific in 1997, the fourth-highest number since accurate records began in 1961.

The National Hurricane Center uses accumulated cyclone energy (ACE) to rank hurricane seasons as above-normal, near-normal, and below-normal. The total ACE of this season is 160*104 kt2 in the east Pacific proper, which qualifies this season as above-normal.

Systems

Tropical Storm Andres

Toward the end of May 1997, a low-level circulation formed off the southern coast of Central America, possibly from a tropical wave that previously traversed the Atlantic Ocean. An area of convection, or thuderstorms, formed on May 31. It organized into Tropical Depression One-E early on June 1, about south of the Gulf of Tehuantepec. After its formation, another circulation developed and became the dominant center. On June 2, the depression intensified into Tropical Storm Andres. On the next day, a trough bypassed the storm to the north, which turned Andres to the southeast. The NHC described the track as "unprecedented". Andres passed about off the coast of Guatemala, before it began weakening due to interaction with the Intertropical Convergence Zone. The convection became amorphous and later shifted to the southeast of the circulation. On June 6 Andres weakened to tropical depression status. It turned northward and moved ashore near San Salvador, El Salvador on June 7, which was the first recorded landfall in the country. The low-level circulation quickly dissipated over land, although the mid-level circulation persisted across Central America. After the featured reached the western Caribbean Sea, a new surface circulation developed, bringing rainfall to Cuba, Florida, and the Bahamas before it was absorbed by a weak trough in the Gulf of Mexico.

The storm prompted tropical storm warnings issued from Punta Galera, Mexico to Champerico, Guatemala, and a tropical storm watch for Guatemala and El Salvador. Officials closed ports along the southern Mexican coastline. Andres produced rainfall along the coast of Mexico, in Guerrero, Oaxaca, and Chiapas, as well as through the Yucatán Peninsula. The highest total in the country was in Mazatán, Chiapas. Heavy rainfall and high seas spread across western Central America. In El Salvador and Nicaragua, the storm led to power outages, traffic accidents, and overflown rivers, as well as destroyed bridges and buildings in Nicaragua. Two fishermen were left missing in Nicaragua, and the storm damaged 91 houses and destroyed 82 more, leaving a total of 1,259 people homeless. There were 4 deaths in El Salvador in Usulután, due to flooding.

Tropical Storm Blanca Tropical Depression Two-E formed from a broad area of low pressure on June 9. Six hours later the depression strengthened into Tropical Storm Blanca. This system developed a good outflow, and reached its peak intensity with winds of 45 mph (75 km/h). However, its circulation was not well-defined and a weakening trend began, and Blanca was downgraded to a depression on June 12. It lost its closed circulation shortly thereafter and was thus declared dissipated.

Blanca briefly threatened land on June 10 as warnings and watches were established by the Mexican Servicio Meteorológico Nacional. Shortly thereafter, a ridge of high pressure turned Blanca away from the coast. As Blanca moved just south of the Mexican coast, it dropped a total of of rainfall at Fincha Chayabe/Maragaritas.

Tropical Storm Carlos

On June 22, showers increased associated with a tropical wave several hundred miles away from land. Three days later, deep convection became more concentrated, and the system became a tropical depression. It intensified into Tropical Storm Carlos as banding features increased and the outflow became better defined. As it moved west, convection diminished as Carlos moved into cooler water. Shortly thereafter, increased wind shear took its toll on Carlos as the low-level center became exposed from the deep convection. Carlos weakened into a depression early on June 27, and dissipated June 28. However, a swirl of clouds remained for a couple of days. Except for Socorro Island, which the system passed close to, Carlos never threatened land.

Hurricane Dolores

In early July, shower activity increased in association with an area of disturbed weather. With surface pressures lower than normal for a tropical disturbance, deep convection increased further and Tropical Depression Six-E formed late on July 5 and reaching tropical storm status the following day and was named Dolores. Despite moderate wind shear, very cold cloud tops formed as the winds increased to , a moderate tropical storm. Moving westward, Dolores strengthened into the first hurricane of the season on July 7 as a ragged eye formed.

Dolores continued to intensify and it reached a peak windspeed of , a strong Category 1 hurricane, two days later. Meanwhile, Dolores became the first hurricane in over two years to cross longitude 125°W. Shortly thereafter, the hurricane started losing strength as it moved over cooler waters. The eye dissipated from satellite imagery while the associated thunderstorm activity became sheared. Dolores weakened back into a tropical storm on July 10 and a tropical depression the next day. The cyclone then crossed into the Central Pacific Hurricane Center's area of responsibility (west of longitude 140°W) while producing minimal shower activity. It dissipated on July 12.

Hurricane Enrique

The first major hurricane of the season originated from a broad area of low pressure on July 8 near the Gulf of Tehuantepec. The thunderstorms gradually became more concentrated and a tropical depression formed on July 12. It strengthened into a tropical storm twelve hours later, and then began to rapidly intensify as convection increased further near the center. It became a hurricane on July 13. Enrique continued to steadily intensify and became a Category 2 hurricane on July 14. The next day, Enrique reached its peak intensity of and peak pressure 960 mbar (hPa) on July 14. Shortly thereafter, the hurricane outflow became asymmetrical and it began to weaken over cool waters. It weakened fairly quickly and was downgraded into a Category 2 hurricane on July 15. It then lost hurricane intensity later that day. On July 16 the winds had decreased further to . Enrique weakened into a depression the next day, and degenerated into a swirl of clouds shortly thereafter.

Hurricane Felicia

A large area of disturbed weather formed on July 13. It then organized into a depression south of Manzanillo, Colima, on July 14. Intensification was delayed by wind shear due to its proximity to Enrique for about two days. However, it became a tropical storm late July 15 as it moved west-northwestward. Continuing to intensify, an eye formed. Based on this, Felicia was upgraded into a hurricane on July 17. Its development was again halted by increased wind shear, and as such it leveled off in intensity. After the shear decreased, Felicia began to intensify and the hurricane's winds reached and its pressure fell to 948 mbar (hPa), making it a moderate low-end Category 4 hurricane. Shear increased for the third time, and then moved into cooler waters. It began to weaken as it moved west-northwest. On July 20, it lost major hurricane intensity. Shortly before being downgraded to a tropical storm, it crossed 140°W. A strong wind shear took toll on Felicia and it was downgraded into a tropical depression July 22.

Hurricane Guillermo

A tropical wave emerged into the Pacific Ocean on July 27. It organized into a depression July 30 and was named Tropical Storm Guillermo the next day. It quickly intensified, reaching hurricane status on August 1. Guillermo became a major hurricane on August 2. It reached Category 4 intensity on August 3. Continuing to rapidly intensify, Guillermo attained Category 5 strength August 4. It reached its peak intensity the next day, with 919 mbar (hPa) minimum central pressure and maximum sustained winds.