Hurricane Willa grows into 'potentially catastrophic' Category 5 monster near Mexico

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 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 and the storm is forecast to make landfall south of Mazatlan Tuesday night as a major Category 3 hurricane or higher.

The major resort areas of Puerto Vallarta and Mazatlan are under tropical storm warnings -- as they are expected to face gusty winds, heavy rain and some flooding -- but they are not under hurricane warnings, because the worst part of the storm is forecast to miss those popular vacation spots.

Willa is expected to hit Mexico's Pacific Coast as at least a Category 3, potentially bringing life-threatening storm surge and flash floods farther inland.

Some regions could see up to 18 inches of rain.

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.