Kathleen brushed the Pacific coast of the peninsula as a hurricane on September 9 and made landfall as a fast-moving tropical storm the next day.

With its circulation intact and still a tropical storm, Kathleen headed north into the United States and affected California and Arizona.

Most Pacific hurricanes are embedded in easterly winds south of the subtropical ridge, and thus move westward—away from large land masses—until they dissipate over cold waters.

[2] However, during early autumn, tropical cyclones generally form closer to the Mexican shoreline than average, making them more likely to recurve, or to curve again, northward under the influence of an approaching trough.

These troughs tend to extend farther to the south during the latter part of the Pacific hurricane season, in the period between late August and early October.

[3] However, many hurricanes that approach the southwestern United States tend to be undergoing extratropical transition as they encounter increased wind shear and markedly cooler sea surface temperatures, and as they interact with the deep troughs that caused them to recurve.

[2] Kathleen is one of only six recorded tropical cyclones in the eastern Pacific Ocean known to have brought gale-force or hurricane-force winds to the Continental United States.

Before passing 40 mi (64 km) east of Socorro Island, Kathleen reached its secondary peak with winds of 65 mph (115 km/h).

It is estimated that the storm peaked in intensity around that time, with winds of 80 mph (130 km/h) and a barometric pressure of 986 mb (986 hPa).

Tropical Storm Kathleen weakened further into a depression over southern California and shortly thereafter, moved across Death Valley.

[8] Because the village is situated atop an alluvial fan,[9] a 40 ft (12 m) wall of water exited a mountain canyon.

[12] Homeowners in Palm Desert suffered $4 million in damage from the storm; the town received more than a year's worth of rainfall in a matter of days.

[17] Flash flood warnings were also issued for parts of California, as well as nearby states Nevada and Arizona, but were dropped as the rain tampered off on September 11.

[18] The National Weather Service's forecast office in Tucson estimates that tropical storm-force winds extended as far east as Pima County, and as far north as Lake Havasu.

One man was killed when the wind blew a palm tree onto his mobile home[18] and 13 people across the state were hurt.