It was initially predicted to track out to sea and remain a weak tropical storm, though it unexpectedly organized rapidly to attain peak winds of 105 mph (169 km/h) on August 24 while located a short distance southeast of southern Baja California Sur.

Land interaction weakened Ignacio to an 80 mph (130 km/h) hurricane by the time it made landfall near La Paz, and it dissipated on August 27 in the central Baja California peninsula.

Cloudiness and convection gradually increased along the wave axis and organized into a distinct area of disturbed weather on August 20 while located a short distance south of Manzanillo, Mexico.

[2] With light vertical wind shear and warm water temperatures, the convection concentrated around a developing low-level circulation,[3] and on August 22 it organized enough for the National Hurricane Center to classify it as Tropical Depression Nine-E while it was located about 115 miles (185 km) west of the Mexico mainland or about 220 miles (350 km) southeast of the southern tip of the Baja California Peninsula.

[1] With an anticyclone located over the southwestern United States and a ridge extending southward into northwestern Mexico, the National Hurricane Center initially predicted the depression to track generally west-northwestward out to sea and reach peak winds of 50 mph (80 km/h).

[3] The tropical depression moved slowly northwestward, with the slow motion persisting for its entire lifetime due to the storm being embedded within the weakness of a mid-level ridge to its north.

[1] Shortly after forming, the storm was located in a marginally favorable environment, with westerly wind shear and dry air approaching the depression[4] and leaving the center of circulation exposed from the convection.

[1] The storm quickly organized and developed well-defined banding features and very well-organized upper-level outflow, and by late on August 23 a warm spot formed in the center of the convection.

[9] However, it turned to the northwest and paralleled the Baja California Peninsula a short distance offshore, resulting in a steady weakening trend due to its interaction with the high terrain.

[2] The slow motion of Ignacio produced heavy rainfall across the southern portion of the Baja California Peninsula, including a peak 24‑hour total of 7.25 inches (184 mm) in Ciudad Constitución.

[11] Flash flooding in desert inland areas washed out roads, causing the Mexican government to restrict traffic through much of the peninsula for up to a week after the storm.

[1] Six municipalities in Baja California were declared disaster areas,[24] and by four days after landfall, the Mexican government prepared emergency funds to meet the immediate needs of the affected citizens.

[25] Due to the storm's slow movement, rainfall was high and the resulting flooding was severe,[1] and Ignacio was responsible for approximately US$21.2 million of damage.