Updated 10:54 a.m. ET
Hurricane Willa, an "extremely dangerous" storm heading to Mexico's Pacific coast, was upgraded to Category 5 by the National Hurricane Center on Monday.
The storm, with maximum sustained winds of 160 mph, is about 135 miles away from Cabo Corrientes, a municipality in southwest Mexico. It is moving north at 7 mph, according to the NHC's latest advisory.
NHC forecasters say the storm is expected to move over or very near Islas Marias on Tuesday and make landfall along the southwestern coast of mainland Mexico.
Just over 9,000 people live in Islas Marias, a chain of nine small islands. Around 1,000 of them are residents; thousands more are prisoners in a penitentiary.
Willa is expected to weaken after Tuesday, but will still be dangerous when it makes landfall, the NHC says.
A hurricane warning is in effect for 180 miles of Mexican Pacific coast between San Blas and Mazatlan. A tropical storm warning is in effect for an additional 190 miles of coast, from San Blas to Playa Perula.
The storm is expected to produce rainfall of 6 to 12 inches across southwestern and west-central Mexico, including western Jalisco, western Nayarit and southern Sinaloa, with 18 inches in some local areas. The NHC says this rainfall will cause storm surge and "life-threatening flash flooding and landslides."
Storm surge and large, destructive waves are likely along parts of the southwestern coast by Tuesday or Tuesday night, especially near where Willa's center will make landfall, the NHC says. Rip currents and large swells will affect beaches in Mexico's southwest.
Farther inland, Willa is expected to produce 2 to 4 inches of rainfall across parts of Zacateca, Durango, southeast Chihuahua and Coahuila, with 6 inches possible in some areas. "This rainfall could cause life-threatening flash flooding," the NHC says.
Willa is the eastern Pacific Ocean's 10th major hurricane of the 2018 season. The NHC classifies major hurricanes as those Category 3 and above.