[1] Four tropical cyclones affected Mexico: first, Hurricane Flossie passed within 75 miles (121 km) of Baja California Peninsula, producing moderate winds and killing seven people.

[7] The deep convection concentrated around a low-level circulation with expanding outflow, and the system developed into Tropical Depression One-E on May 21,[8] while located about 400 mi (640 km) south of Manzanillo, Mexico.

Located in an area of warm waters, Adolph exhibited a well-defined outflow pattern, and rapidly strengthened to attain hurricane status on June 17 as a banding-type eye developed.

[12] As Adolph moved north towards Mexico while about 290 mi (470 km) off the coast, the Mexican government issued a tropical storm warning and a hurricane watch from Punta Tejupan to Cabo Corrientes, Jalisco.

[15] Although the outer rainbands warmed slightly in the hours after the formation, the convection near the center deepened further with favorable upper-level outflow,[16] and the depression strengthened into Tropical Storm Barbara early on July 8.

[14] After moving into an area of light vertical shear and warm water temperatures,[18] Barbara quickly intensified to reach major hurricane status on July 10.

After maintaining its intensity for 24 hours,[14] increased wind shear from an upper-tropospheric trough degraded the appearance of the deepest convection, and the eye became obscured from satellite images.

[19] After weakening to a 115 mph (185 km/h) hurricane, Barbara maintained its intensity for 30 hours before moving into an area with very warm waters and a favorable upper-level environment.

Barbara continued westward under the influence of a subtropical ridge to its north, and began to steadily weaken on July 14 as it moved into an area of cooler water temperatures.

As a depression with little to no convection near its center, Barbara continued west-northwestward until dissipating on July 18 while located 720 mi (1,160 km) east-southeast of Hilo, Hawaii.

As the depression was situated in an area with warm waters and moderate upper-level outflow, the system was forecast to slowly intensify to a 50 mph (80 km/h) tropical storm.

[23] The storm continued to steadily intensify, and subsequent to the development of an eye, Cosme strengthened into a hurricane late on July 19, while located 380 miles (610 km) west-southwest of the southern tip of Baja California Peninsula.

Thunderstorms along the wave axis became more concentrated a few hundred miles south of the Gulf of Tehuantepec, and the system developed into Tropical Depression Five-E on July 24 while located 500 mi (800 km) southwest of Manzanillo, Mexico.

[26] Located in an area of weak steering currents and easterly wind shear, the tropical depression drifted to the north-northeast while the convection was displaced up to 70 mi (110 km) west of the circulation.

Late on July 28, Dalila reached a peak intensity of 65 mph (105 km/h) at a position 570 mi (920 km) southwest of Cabo San Lucas.

A circulation developed, and the system organized into Tropical Depression Six-E on August 1 while located about 520 mi (840 km) south of the southern tip of Baja California Peninsula.

[29] Erick gradually strengthened as it moved to the west-northwest, and reached peak winds of 65 mph (105 km/h) on August 5 while located about 720 miles (1,160 km) southwest of Cabo San Lucas.

After maintaining its peak intensity for 18 hours and passing within 75 mi (121 km) of Baja California Peninsula, Flossie weakened over cooler waters and degenerated to a tropical storm on August 12.

The large circulation of Hurricane Flossie produced gusty winds along the west coast of Mexico and southern Baja California Peninsula.

A circulation developed within its deep convection, and the system organized into Tropical Depression Seven-E on August 19 while located about 115 mi (185 km) southeast of Acapulco.

[34] With well-defined outflow and continually developing convection, forecasters predicted Gil to strengthen more and attain hurricane status within two days of becoming a tropical storm.

[37] On August 22, the cloud pattern of Gil became better organized, though the low-level circulation was located to the northeast of the deep convection due to the wind shear.

[40] Later that day the storm attained a peak strength of 65 mph (105 km/h) while located 380 mi (610 km) southwest of the southern tip of Baja California Peninsula.

The system quickly developed deep convection and a low-level circulation, and on September 1 it organized into Tropical Depression Nine-E while located about 170 mi (270 km) off the southwest coast of Mexico.

[42] The eye became better defined the next day, and Henriette attained a peak intensity of 100 mph (160 km/h) as the northern portion of the eyewall moved over southern Baja California Peninsula.

It continued to the north, and after passing a short distance east of Baja California Peninsula it made landfall on Topolobampo in the state of Sinaloa with winds of 80 mph (130 km/h).

Based on the development of a low-level circulation, it is estimated the system organized into Tropical Depression Eleven-E on September 16 while located around 290 miles (470 km) south of Manzanillo, Mexico.

Possibly due to increased northeasterly wind shear from an upper-level trough, Juliette stopped its intensification trend, though as it turned to the west it again re-organized.

On September 20, while located 420 miles (680 km) southwest of Cabo San Lucas, Juliette attained a peak strength of 150 mph (240 km/h), the strongest tropical cyclone of the season and a Category 4 on the Saffir-Simpson Hurricane Scale.

An eastward moving trough of low pressure turned the hurricane to the north-northeast into an area of cooler water temperatures and increased wind shear.