[1] On August 20, a tropical wave became discernible about 800 miles (1300 km) off the coast of Mexico,[2] which in the next day developed a large area of convection, or thunderstorms.

With banding features becoming more prominent, the National Hurricane Center (NHC) classified the system as Tropical Depression Eleven-E about 345 miles (555 km) south-southeast of the southern tip of the Baja California Peninsula.

[6] Convection continued to develop to the west of the center,[7] and late on August 23, a ship report confirmed the depression intensified Tropical Storm Julio.

[8] Initially, the persistent shear left the center partially exposed from the thunderstorm activity, though upper level conditions gradually became more favorable for strengthening.

[10] Shortly thereafter, the center became difficult to locate,[11] and late on August 24 the storm moved ashore along the southwestern coast of the Baja California Peninsula.

[18] As Julio made landfall, it produced lightning and locally heavy rainfall,[18] which left more than a dozen communities isolated due to flooding.