Mexican authorities have placed four southern coastal states on high alert ahead of Tuesday's expected arrival of Jova, a major hurricane barreling in from the Pacific.
The Miami-based US National Hurricane Center said in a 0300 GMT bulletin that Jova was packing maximum sustained winds of 195 kilometers (120 miles) per hour and was 255 kilometers (158 miles) southwest of the busy port city of Manzanillo, in Colima state.
It was moving north-northeast at 11 km/h (7 mph).
Jova has strengthened to a category three storm on the five-level Saffir-Simpson scale and was forecast to become a category four before weakening as it makes landfall on Tuesday.
"On the forecast track, the center of the hurricane will be near the coast of Mexico in the hurricane warning area by Tuesday afternoon or evening," the NHC said.
"Some fluctuations in strength could occur during the next day or so but Jova is still expected to reach the coast of Mexico as a major hurricane."
Mexican authorities issued hurricane alerts for large swaths of the Pacific coastline.
The zone stretched north from the port of Lazaro Cardenas in Michoacan for almost 480 kilometers (298 miles), encompassing the popular tourist cape of Cabo Corrientes in Jalisco, Mexico's meteorological institute said.
Colima, Jalisco, Michoacan and Nayarit state to the north were all put on guard for possible landslides from heavy rain expected to be dumped by the ninth Pacific hurricane of the season.
"A dangerous storm surge is expected to produce significant coastal flooding near and to the east of where the center makes landfall," the NHC warned.
The surge, said the hurricane center, "will be accompanied by large and destructive waves" as well as torrential rainfall with accumulations of up to 20 inches (50 centimeters) in some areas.
Several major storms or hurricanes have buffeted Mexico's Pacific coast in recent months but most have remained offshore.
The season's first named storm, Arlene, left at least 16 people dead and drenched much of the country in July.
Tropical storms and hurricanes last year caused flooding and mudslides in Mexico that killed 125 people, left hundreds of thousands homeless and caused more than $4 billion in damage.