Photo: The Canadian Press

Hurricane Willa has grown rapidly into an "extremely dangerous" near-Category 5 storm in the eastern Pacific, on a path to smash into Mexico's western coast between Mazatlan and Puerto Vallarta by Wednesday.

The governments of Sinaloa and Nayarit states ordered coastal region schools to close on Monday and began preparing emergency shelters ahead of the onslaught.

The U.S. National Hurricane Center said that Willa could "produce life-threatening storm surge, wind and rainfall over portions of southwestern and west-central Mexico beginning on Tuesday." It predicted that Willa could become a Category 5 hurricane later Monday, generating life-threatening surf and rip tide conditions.

A hurricane warning was posted for Mexico's western coast between San Blas and Mazatlan, including the Islas Marias, a nature reserve and federal prison directly in the forecast track of the storm.

Tropical storm warnings ranged from Playa Perula north to San Blas and from Mazatlan north to Bahia Tempehuaya. The centre said Willa is expected make landfall late Tuesday or early Wednesday.

By early Monday, Willa had maximum sustained winds of 155 mph and was centred about 200 miles south-southwest of the Islas Marias. It was moving north at 7 mph.

The hurricane centre said 6 to 12 inches of rain should fall — and some places could see up to 18 inches — on parts of western Jalisco, western Nayarit and southern Sinaloa states. It warned of the danger of flash flooding and landslides in mountainous areas.

Farther to the south, Tropical Storm Vicente weakened but was still expected to produce heavy rainfall and flooding over parts of southern and southwestern Mexico.

By early Monday, its core was about 195 miles southeast of Acapulco. The hurricane centre said it could produce 3 to 6 inches of rain in parts of Guerrero, Michoacan, Colima and Jalisco states.