The 2003 Pacific hurricane season was the first season to feature no major hurricanes (storms of Category 3 intensity or higher on the Saffir–Simpson hurricane wind scale) since 1977. The season officially began on May 15, 2003 in the Eastern North Pacific (east of 140°W), and on June 1 in the Central (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 tropical cyclogenesis occurs in these regions of the Pacific. The season featured 16 tropical storms, 7 of which intensified into hurricanes, which was then considered an average season. Damage across the basin reached US$129 million, and 23 people were killed by the storms.

Despite the overall lack of activity, the season produced an unusually large number of tropical cyclones that affected Mexico, with eight tropical cyclones making landfall on either side of Mexico, which was the second highest on record. Tropical Storm Carlos struck Oaxaca in late June, resulting in nine fatalities. In late August, Hurricane Ignacio struck the Baja California peninsula, killing four people and inflicting US$21 million in damage. In September, Hurricane Marty affected the same areas as Ignacio, and was responsible for 12 casualties and US$100 million in damage, making Marty the costliest and deadliest storm of the season. In October, hurricanes Olaf and Nora struck western Mexico as tropical depressions, causing slight damage and one casualty.

Activity in the Central Pacific was below average, with only one tropical depression forming in the basin and one hurricane entering the basin from the East Pacific. In mid-August, Hurricane Jimena passed just to the south of Hawaiʻi; it was the first storm to directly threaten Hawaii in several years. Also, the remnants of Tropical Storm Guillermo moved into the basin on August 12, prior dissipating the following day.

Seasonal forecasts +Predictions of tropical activity in the 2003 seasonSourceDateNamedstormsHurricanesMajorhurricanesRefEastern Average (1981–2010) 16 9 4 Eastern - SMN May 13, 2003 15 6 2 Eastern - NOAA June 12, 2003 11–15 6–9 2–5 Eastern Actual activity 16 7 0 Central Average 4–5 1 – Central - NOAA May 19, 2003 2–3 – – Central Actual activity 1 1 0

On May 16, 2003, the Servicio Meteorológico Nacional (SMN, National Meteorological Service) released their prediction for tropical cyclone activity in the eastern Pacific. A total of 15 named storms, 6 hurricanes, and 2 major hurricanes was forecast. Three later days, National Oceanic and Atmospheric Administration (NOAA) issued its Central Pacific hurricane season forecast, calling for a slightly below-average level of activity due to the expected development of La Niña. La Niña conditions generally restrict tropical cyclone development in the Northeast Pacific, which is the opposite of its effect in the Atlantic. On June 12, 2003, NOAA issued a forecast for the East Pacific hurricane season – the first time it had done so. The scientists expected that La Niña conditions would develop, and predicted a 50 percent chance of below normal activity and a 40 percent chance of near normal activity.

Seasonal summary

There were 16 named storms and 7 hurricanes during the 2003 Pacific hurricane season, which is comparable with the long-term averages. For the first time since 1977, there were no major hurricanes, where the long-term average is four. (Major hurricanes are storms of Category 3 intensity or higher on the Saffir–Simpson hurricane wind scale.) The first hurricane, Ignacio, formed on August 24. This is the latest formation of the first hurricane of a season recorded in the East Pacific since reliable satellite observation began in 1966. The accumulated cyclone energy (ACE) index for the 2003 Pacific hurricane season, at 53.4 units in the Eastern Pacific and 3.3 units in the Central Pacific, places the season among the top 10 least active seasons since 1971, when reliable records began.

While the total activity was below average, there was an unusually high number of landfalls in Mexico. Eight Pacific and North Atlantic tropical cyclones had a direct impact in Mexico in 2003, second only to 1971, when nine did so. This is well above the long-term average of 4.2 Atlantic and East Pacific storms affecting Mexico. Five Pacific storms impacted Mexico; Hurricanes Ignacio and Marty both made landfall in the state of Baja California Sur at hurricane intensity. Two other storms hit mainland Mexico as tropical storms and a third as a tropical depression. Three storms hit Mexico within a very short space of time: the Pacific hurricanes Nora and Olaf, and the Atlantic Tropical Storm Larry. As a result of the flooding caused by these storms, disaster areas were declared in 14 states.

Activity in the Central Pacific was below average, with only one tropical depression forming in the basin and one hurricane entering the basin from the East Pacific. A third system, Tropical Storm Guillermo, weakened to a remnant low just to the east of the Central Pacific Hurricane Center's area of responsibility. Although activity was generally low, Hurricane Jimena was the first direct threat to the Hawaiian Islands for several years and a hurricane watch was issued for the island of Hawaii. Jimena passed to the south, but still brought tropical-storm-force gusts and heavy rain to the island.

Systems

Tropical Storm Andres

An area of disturbed weather developed south of Guatemala on May 10 within a broad area of low pressure. While tracking westward, the disturbance became classifiable by the Dvorak technique on May 18. Following the development of a closed low-level circulation, the disturbance was classified as a tropical depression around 18:00 UTC on May 19 roughly south-southeast of Cabo San Lucas. The depression strengthened into Tropical Storm Andres the next day. Despite increasing wind shear from an anticyclone causing the system's convection to become displaced from the circulation, overall banding features improved, and Andres obtained its peak strength with winds of by 1800 UTC on May 20. A further increase in shear, soon followed by a decrease in ocean temperatures, caused Andres to weaken on May 25. It was downgraded to a tropical depression on May 25, became a post-tropical cyclone at 12:00 UTC that day, and dissipated on May 26 without affecting land.

Tropical Storm Blanca

In mid-June, a tropical wave interacted with a lingering area of disturbed weather near the southwestern Mexican coast. Following an increase in organization, the combined disturbance was classified as a tropical depression at 00:00 UTC on June 17. The storm strengthened and became Tropical Storm Blanca 12 hours later. The storm moved slowly to the west and reached its peak on June 18 with winds; around this time, the cyclone displayed an eye-like feature on weather satellite. Under the influence of strong shear from the southeast, Blanca began to weaken and move erratically, although intermittent bursts of deep convection continued. The storm degenerated to a tropical depression on June 20 and a post-tropical cyclone by 12:00 UTC on June 22. The remnants of Blanca were tracked for an additional two days. There were no effects from Blanca on land.

Tropical Storm Carlos

Tropical Storm Carlos formed from a tropical wave that crossed Central America on June 20. After gradually organizing, the wave was designated a tropical depression at 00:00 UTC on June 26 and further upgraded to Tropical Storm Carlos after twelve hours. The system moved generally northward and developed an eye, which was visible on Puerto Ángel radar. Carlos attained peak winds of shortly before making landfall about west of Puerto Escondido, or about east-southeast of Acapulco. The storm rapidly deteriorated to a remnant low by 18:00 UTC on June 27, which persisted until dissipation on June 29.

Carlos produced heavy rainfall across portions of southern Mexico, peaking at in two locations in Guerrero. In northwestern Oaxaca, seven people were killed when the heavy rainfall triggered a mudslide. Mudslides were reported elsewhere in the state, and about 30,000 homes were damaged. Throughout its path, the storm affected about 148,000 people. Monetary damage totaled 86.7 million pesos (2003 MXN, US$8 million). In addition to the seven deaths across Oaxaca, two fishermen were reported missing.

Tropical Storm Dolores

A tropical wave entered the East Pacific on June 30 and four days later became classifiable by the Dvorak technique while south of Manzanillo, Colima. Convection coalesced around an area of low pressure as it moved west. The disturbance organized into Tropical Depression Four-E by 06:00 UTC on July 6 about to the south-southwest of Baja California Sur. It soon strengthened further, becoming Tropical Storm Dolores and reaching its peak intensity with winds of six hours later. This peak was short-lived as an increase in east-northeasterly shear stripped the storm of its convection and caused it weaken back to a tropical depression on July 7. The northwest motion caused by a mid-level ridge north and northeast of the cyclone brought it over colder water, and the system degenerated into a post-tropical remnant low around 06:00 UTC on July 8. Dissipation occurred the next day.

Tropical Storm Enrique

On July 6, a tropical wave entered the Northeastern Pacific Ocean. An area of low pressure developed and began to show signs of organization on July 9. The disturbance was designated a tropical depression around 12:00 UTC on July 10 while located about south-southeast of Baja California Sur. The storm became more organized and was named Tropical Storm Enrique 24 hours later as it tracked west-northwest. As Enrique strengthened and upper-level outflow expanded in all directions, forecasters briefly anticipated it to become a hurricane. The cyclone instead peaked with winds of early on July 12, after which point it encountered cool waters at a high latitude. Accordingly, Enrique rapidly weakened despite low wind shear. The storm degenerated into a remnant low around 00:00 UTC on July 14 and continued to move west before dissipating three days later.

Tropical Storm Felicia

A tropical wave passed over Central America on July 12 and began to show signs of organization south of the Gulf of Tehuantepec two days later, prompting Dvorak classifications on the system. As it continued to develop, the NHC designated the system a tropical depression at 18:00 UTC on July 17 about south of Manzanillo. Tracking westward on the southern periphery of a ridge, the depression became Tropical Storm Felicia twelve hours later, and forecasters anticipated further strengthening into a minimal hurricane. However, the storm remained disorganized and peaked with winds late on July 18. The storm gradually weakened under increasing shear as it headed west, weakening back to a tropical depression on July 20 and degenerating to a remnant low around 12:00 UTC on July 23. After a west-northwestward turn, the remnant low entered the Central Pacific, where it dissipated well east of Hawaii on July 24. Felicia did not impact land.

Tropical Storm Guillermo