Two days later, a new tropical depression developed offshore Guatemala, which became Hurricane Juliette by September 22 as it rapidly intensified off western Mexico.

On September 24 it strengthened into a Category 4 hurricane on the Saffir-Simpson scale, only to weaken due to an eyewall replacement cycle, then re-intensified a day later to attain maximum sustained winds of 230 km/h (145 mph), with a minimum barometric pressure of 923 mbar (27.3 inHg).

At 18:00 UTC on September 19, Tropical Depression Nine developed in the southwestern Caribbean Sea, located about 60 mi (95 km) north-northwest of San Andrés.

[1] Upon its formation, the depression already had a circular upper-level outflow, which National Hurricane Center (NHC) forecaster Stacy Stewart described as "impressive... more indicative of a mature tropical cyclone."

The NHC anticipated that the westward track would continue, ultimately resulting in a significant tropical cyclone in the eastern Pacific Ocean.

The system quickly reorganized, and at 06:00 UTC on September 21, a small tropical depression developed about 165 km (105 mi) south of Guatemala.

Despite the proximity to land, the small system quickly intensified due to warm water temperatures and light wind shear.

At 18:00 UTC on September 21, the NHC initiated advisories on the system, naming it Tropical Storm Juliette, based on observations from the Hurricane Hunters.

[5] Although the thunderstorms temporarily decreased near its center, Juliette developed good outflow by September 22, a sign of a maturing tropical cyclone.

[7] Later that day, an eye developed in the center of the convection, and by 12:00 UTC, Juliette attained hurricane status, with maximum sustained winds reaching 120 km/h (75 mph).

NHC forecaster Stacy Stewart noted that "this type of erratic motion is not unusual for tropical cyclones that undergo rapid deepening."

At 06:00 UTC on September 24, the hurricane attained an initial peak intensity of 215 km/h (130 mph), making Juliette a Category 4 on the Saffir-Simpson scale.

[10][3] However, the hurricane underwent an eyewall replacement cycle, in which the small inner eye dissipated, causing the winds to drop to 175 km/h (110 mph) by late September 24.

[3][12] Shortly after its peak, Juliette's path turned more to the northwest toward the Baja California peninsula, drawn northward by an eastward-moving trough off the west coast of the United States.

[14][3] Early on September 28, the hurricane passed about 110 km (70 mi) west of Cabo San Lucas along the southern tip of the Baja California peninsula.

[15][3][16] The combination of land interaction and cooler temperatures caused the hurricane to weaken further, and Juliette briefly dropped to tropical storm status late on September 28.

[3][17] The thunderstorms redeveloped over the center early on September 29, and Juliette re-intensified to hurricane status for about 12 hours, only to weaken again due to land interaction.

[3] Soon after moving over land, Juliette weakened into a tropical depression and became disorganized, as stronger wind shear stripped the thunderstorms from the circulation.

Instead, the circulation continued to the northwest over water, and the NHC resumed advisories on October 2, after Juliette generated enough thunderstorms to be re-designated a tropical depression.

The government of Mexico issued tropical storm warnings for the southern Baja California peninsula on September 26, two days before Juliette's closest approach to the region.

[26] A large cyclone, Juliette affected much of the Pacific coast of Mexico with clouds, rainfall, and high waves, particularly the states of Baja California Sur and Sonora.

[13] The heaviest rainfall occurred along the southern tip of the Baja California peninsula, with a maximum precipitation total of 1,011 mm (39.80 in) recorded at Santiago.

The floodwater exceeded the capacity of water systems, causing landslides and road damage, including along Mexican Federal Highway 15.

In California, the thunderstorms produced a dust storm, and a wind gust of 39 mph (63 km/h) recorded at Palm Springs International Airport.

[44][3][45] Following the significant damage across southern states, Mexico deployed its military to deliver 50 tons of food and water to the Los Cabos region.

[48] Due to the road damage, supplies were unable to be driven into Los Cabos, which required food and fuel to be transported there by ship.

[26] The damage and disruptions caused a 50% reduction in tourism activity in Los Cabos for about 20 days, a lull in travel also partly attributable to the September 11 attacks in the United States earlier in the month.