Hurricane Max was a rapidly-forming tropical cyclone that made landfall in southwestern Mexico, causing minor damage. The sixteenth tropical cyclone, thirteenth named storm, and seventh hurricane of the 2017 Pacific hurricane season, Max developed from a trough of low pressure near the southwestern coast of Mexico on September 13. The storm tracked northeastward under the influence of a mid-level ridge and rapidly strengthened as a result of warm ocean temperatures in its path. Max strengthened into a hurricane on September 14 and peaked as a high-end Category 1 hurricane on the Saffir–Simpson scale shortly before making landfall in the Mexican state of Guerrero. Rapid weakening ensued as Max moved over the mountainous terrain of Mexico, and it weakened below hurricane strength early on September 15. At 12:00 UTC that day, Max dissipated over the mountains of southern Mexico.
The Government of Mexico issued numerous tropical storm and hurricane watches and warnings in anticipation of Max's arrival. Due to the small size of the cyclone, effects were relatively localized and confined to a small area. Regardless, large waves, flooding, mudslides, and sinkholes caused by Max caused moderate damage in the state of Guerrero. Over 1,500 residences suffered flood damage, and numerous roads across the state, including Mexican Federal Highway 200, were closed due to landslides and sinkholes. The storm exacerbated the effects of the 2017 Chiapas earthquake, which killed 98 people. Four deaths were associated with Max: two in Guerrero and two in Chiapas. Damage from the storm and another earthquake that followed shortly was estimated at MX$1.35 billion (US$76.4 million).
Meteorological history
A tropical wave – the same that spawned Hurricane Jose in the Atlantic – crossed Central America and entered the Pacific Ocean on September 11. Vorticity associated with the wave soon became intertwined within a broad cyclonic gyre in the lower levels of the atmosphere. On September 13, a large area of convection, or thunderstorms, associated with this system began to organize a few hundred miles southwest of the coast of Mexico. Satellite imagery indicated that a well-defined center of circulation had formed, and at 12:00 UTC that day, the disturbance was upgraded to a tropical depression while located west-southwest of Acapulco, Mexico. Initially, the depression was not forecast to intensify, due to a portion of the circulation already interacting with land. Six hours later, the depression strengthened into a tropical storm, receiving the name Max, while being steered east-northeastward by a mid-level ridge. The cloud pattern of the cyclone continued to consolidate, with a well-defined curved rain band wrapping around the center. Located over water temperatures as warm as , and under a divergent upper-level environment, Max underwent a period of rapid intensification.
A microwave pass on the afternoon of September 13 revealed that Max developed a mid-level eye, signifying that the storm had formed an inner core. Radar from Acapulco showed that the structure of the storm continued to improve, with a well-defined eye surrounded by a closed eyewall. Based on these signals, it was estimated that Max strengthened into a hurricane just before 12:00 UTC on September 14. Around this time, Max's forward direction turned to the east, moving right offshore the shoreline of Mexico. Max continued to strengthen throughout the day, with an eye becoming distinct for a few hours on both visible and infrared satellite imagery. Max reached its peak intensity with maximum sustained winds of shortly before making landfall in Guerrero, Mexico at 18:00 UTC on September 14. The eye subsequently disappeared, and the radar and satellite presentations deteriorated significantly while moving inland. Located over the mountainous terrain of Mexico, Max rapidly weakened to a tropical depression at 06:00 UTC on September 15. The circulation of Max completely dissipated at 12:00 UTC.