(HOUSTON) -- Hurricane Willa strengthened to a powerful Category 5 storm Monday morning, taking aim at the Mexican coast and threatening to deliver life-threatening storm surge, wind and rain.
Now packing 160 mph winds, some strengthening was still possible for the storm Monday, making Willa "potentially catastrophic" for Mexico, the National Hurricane Center warned.
The storm is moving north toward the southwest Mexican coast.
It's expected to weaken when it makes landfall Tuesday but is forecast to bring large waves, dangerous storm surge, gusty winds and heavy rain.
Mexico will begin to feel the impacts of Willa late Tuesday morning. The storm is forecast to make landfall south of Mazatlan Tuesday night as a major Category 3 hurricane or higher, potentially bringing life-threatening storm surge and flash floods farther inland.
Some regions of Mexico could see up to 18 inches of rain.
The major resort area of Puerto Vallarta is under a tropical storm warning -- as it is expected to face gusty winds, heavy rain and some flooding -- but not under a hurricane warning, because the worst part of the storm is forecast to miss the popular vacation spot.
Willa is expected to hit an underpopulated region of Southwest Mexico, staying well north of Puerto Vallarta.
Willa is then expected to weaken after passing over the Sierra Madre mountains, and the remnants of the storm will likely will bring significant rainfall to Texas.
Some portions of southern and central Texas could see as much as 4 inches of rain this week.
Heavy rain also is possible in Louisiana and Mississippi.
Copyright © 2018, ABC Radio. All rights reserved.