The 2024 Pacific hurricane season was a slightly below-average yet destructive season that saw 15 tropical cyclones develop overall, of which 13 developed into named storms. Among them, 5 developed into hurricanes, of which 3 intensified into major hurricanes. The season officially began on May 15 in the eastern Pacific basin (east of 140°W) and on June 1 in the central Pacific (between 140°W and the International Date Line); both ended on November 30. These dates, adopted by convention, historically describe the period in each year when most subtropical or tropical cyclogenesis occurs in these regions of the Pacific Ocean. For the third consecutive year, there were no pre-season tropical cyclones in either basin, and the season got off to the slowest start of any Pacific hurricane season on record in the satellite era, with the first eastern Pacific tropical storm, Aletta, not forming until July 4. The first (and only) central Pacific tropical cyclone, Hurricane Hone, formed on August 22, becoming the first named storm to develop in the basin since 2019. The final system of the season, Tropical Depression FourteenE, dissipated on November 7.

Several storms impacted land this year. Hurricane Hone dropped very heavy rainfall over the Big Island of Hawaii after passing just offshore at Category 1 strength. The remnants of Hurricane Gilma impacted the islands several days later, though neither cyclone caused significant damage. Tropical Storm Ileana grazed the coast of northwestern Mexico, resulting in flooding. Hurricane John made landfall on southern Mexico twice after rapidly intensifying to a Category 3 hurricane, causing 29 deaths and an estimated $2.45 billion in damage. The strongest storm of the season was Hurricane Kristy, which became the first Category 5 Pacific hurricane in a non-El Niño year since Celia in 2010. __TOC__

Seasonal forecasts Record Namedstorms Hurricanes Majorhurricanes Ref Average (1991–2020): 15 8 4 Record high activity: 1992: 27 2015: 16 2015: 11 Record low activity: 2010: 8 2010: 3 2003: 0 Date Source Namedstorms Hurricanes Majorhurricanes Ref May 6, 2024 SMN 15–18 7–9 3–4 May 23, 2024 NOAA 11–17 4–9 1–4 Area Namedstorms Hurricanes Majorhurricanes Ref Actual activity: EPAC 13 4 3 Actual activity: CPAC 1 1 0 Actual combined activity: 14 5 3

In advance of each Pacific hurricane season, forecasts of hurricane activity are issued by the United States National Oceanic and Atmospheric Administration (NOAA)'s Climate Prediction Center and Mexico's Servicio Meteorológico Nacional (SMN). These include weekly and monthly changes in significant factors that help determine the number of tropical storms, hurricanes, and major hurricanes within a particular year. According to NOAA, the average eastern Pacific hurricane season between 1991 and 2020 contained roughly 15 tropical storms, 8 hurricanes, 4 major hurricanes, with a near-normal accumulated cyclone energy (ACE) index between 80 and 115. Broadly speaking, ACE is a measure of the power of a tropical or subtropical storm multiplied by the length of time it existed. It is only calculated for full advisories on specific tropical and subtropical systems reaching or exceeding wind speeds of . NOAA typically categorizes a season as above-average, average, or below-average based on the cumulative ACE index, but the number of tropical storms, hurricanes, and major hurricanes within a hurricane season is sometimes also considered.

On May 6, 2024, SMN issued its forecast for the season, forecasting a total of 15–18 named storms developing, with 7–9 hurricanes, and 3–4 major hurricanes. On May 23, 2024, NOAA issued their outlook, calling for a below-normal season with 11–17 named storms overall, 4–9 hurricanes, 1–4 major hurricanes, and an ACE index of 50% to 110% of the median.

Seasonal summary

Officially, the 2024 Pacific hurricane season began on May 15 in the Eastern Pacific, on June 1 in the Central Pacific, and both ended on November 30. The season began unusually quiet, with several weeks of inactivity throughout the basin. The first system, short-lived Tropical Storm Aletta formed on July 4, which made it the latest first named Pacific tropical cyclone to form in the satellite era. It was followed nearly three weeks later by Tropical Storm Bud, another short-lived storm that dissipated over the open Pacific. A week later on July 31, Hurricane Carlotta formed out of a low-pressure area, later developing into the first hurricane of the season. Three more storms formed in quick succession during the first week of August: Daniel, Emilia, and Fabio; all four storms were simultaneously active in the basin on August 5. After the last of these storms, Emilia, dissipated on August 9, the basin fell into another lull in activity.

Tropical cyclogenesis resumed in late August with the formation of Hurricane Gilma on August 18. Gilma became the first major hurricane of the season on August 22. Hurricane Hone developed in the Central Pacific basin also on August 22, becoming the first tropical cyclone to form in that basin in five years. They were joined by Tropical Storm Hector on August 25 in the eastern Pacific proper. Hone would later move out of the basin into the Western Pacific. Hone and Gilma were the only Central Pacific tropical cyclones this year.

A two-week break in activity came to an end when Tropical Storm Ileana formed on September 12. The storm grazed northwestern Mexico twice before dissipating. Hurricane John developed over a week later and rapidly intensified into the second major hurricane of the season prior to making landfall in southern Mexico. In late October, Hurricane Kristy formed off the coast of southern Mexico, in-part from the remnants of Atlantic basin Tropical Storm Nadine, and intensified to Category 5 strength out in the open ocean. It was the first Category 5 Pacific hurricane in a non-El Niño year since Celia in 2010. Tropical Storm Lane and Tropical Depression FourteenE developed in early November; both systems remained out to sea. This season's ACE index was approximately 82 units. This number represents sum of the squares of the maximum sustained wind speed (knots) for all named storms while they are at least tropical storm intensity, divided by 10,000. Therefore, tropical depressions are not included.

Systems

Tropical Storm Aletta

A tropical wave that led to the formation of Atlantic Tropical Storm Chris approached Central America from June 27–28. The southern part of this wave interacted with the monsoon trough over the far eastern Pacific, and the combined feature, as well as increased convection over the area, led to formation of a low pressure area on July 3. The low organized into a tropical depression at 06:00 UTC on July 4. The system strengthened into a tropical storm six hours later and was named Aletta, the latest-forming first named storm in the East Pacific in the satellite era. Aletta simultaneously peaked in intensity as a minimal tropical storm, retaining its strength for twelve hours. A 12:56 UTC Synthetic Aperture Radar (SAR) pass on July 4 depicted Aletta’s gale-force wind field extent to only 15 nm (28 km) in radius. Aletta eventually weakened back to a tropical depression the following day before degenerating into a remnant low by 00:00 UTC on July 6. The low subsequently dissipated later that day.

Tropical Storm Bud

A tropical wave left the coast of Africa on July 10. The wave approached Central America over a week later, interacting with the Eastern Pacific monsoon trough. The combined disturbance continued westward, and began to organize its shower and thunderstorm activity on July 23 to the southwest of Mexico. The system eventually organized into a tropical depression at 12:00 UTC on July 24, about 400 nautical miles south of Cabo San Lucas. Bud moved to the northwest, and despite being embedded in an environment of dry air, the system was able to strengthen modestly and achieved its peak intensity at 6:00 UTC on July 25, with maximum sustained winds of and a minimum barometric pressure of . Continued movement through a dry-air environment caused Bud to weaken later that day, and the storm degenerated to a post-tropical cyclone the following day. Bud's remnant low drifted to the southwest until dissipating by July 29.

Hurricane Carlotta

A fast-moving tropical wave left the coast of Africa on July 18. The wave crossed Central America just over a week later, entering the Eastern Pacific and spawning an area of low pressure. The disturbance developed sufficiently organized deep convection to become a tropical depression at 12:00 UTC on July 31, several hundred miles southwest of Manzanillo, Mexico. Favorable environmental conditions allowed the depression to intensify into Tropical Storm Carlotta six hours later. Carlotta steadily became better organized over the following days. After passing just to the north of Clarion Island early on August 2, the storm strengthened into a hurricane. Hurricane Carlotta reached its peak intensity early the following day with maximum sustained winds of maximum sustained winds of and a minimum barometric pressure of . However, Carlotta continued to move westward and encountered cooler sea surface temperatures (SSTs), causing the cyclone to weaken to a tropical storm at 12:00 UTC on August 4. Carlotta lost most of its deep convection by late that day within a stable environment over even cooler SSTs, and the storm degenerated to a remnant low late on August 5. The remnant low drifted southwestward before dissipating over open waters on August 8.

Tropical Storm Daniel

On July 26, the NHC highlighted a low-pressure area in the western portion of the basin for potential tropical development. The disturbance began to quickly organize on August 2, and the formation of a well-defined circulation and tropical-storm-force winds led to its designation as Tropical Storm Daniel the following morning. Daniel struggled to organize as it meandered within an environment of moderate wind shear and dry air. Moving northeastward around Hurricane Carlotta's larger circulation, Daniel became increasingly embedded and less distinctive from the surrounding Intertropical Convergence Zone. Daniel weakened to a tropical depression the afternoon of August 5. The storm opened up into a trough later that day.

Tropical Storm Emilia

On August 3, the NHC began monitoring a tropical disturbance well to the south of the Baja California peninsula, and to the west of another developing disturbance. The following day, the system quickly developed into Tropical Depression FiveE. The newly-formed cyclone strengthened into Tropical Storm Emilia early on August 5. The disturbance east of Emilia developed into Tropical Storm Fabio the same day, and the cyclones began to interact with one another. Emilia steadily strengthened as it became the dominant storm in its interaction with Fabio. After initially moving southward, the storm gradually turned back to the west then northward around Fabio. Emilia reached its peak intensity early on August 7 with maximum sustained winds of and a minimum central pressure of . Later that day, Emilia absorbed the remnants of Fabio as it accelerated northward. Heading over cooler waters, Emilia began to quickly weaken. The storm produced little organized convection the following day, as it crossed the isotherm towards even colder SSTs. The storm degenerated into a post-tropical remnant low by 03:00 UTC on August 9, about 980 mi (1580 km) west of the southern tip of the Baja California peninsula.

Tropical Storm Fabio