Hurricane Otis barreled into southern Mexico's Pacific coast early Wednesday morning, making landfall as a dangerous Category 5 storm before weakening over land. The National Hurricane Center warned the area around Acapulco could see "catastrophic damage." Videos posted online showed strong wind and rain lashing the popular beach resort city as the storm made landfall.

Mexico's national civil protection agency said in a tweet that parts of Guerrero state were already seeing power cuts as the storm came ashore, and it warned residents in the area to remain calm and seek shelter until authorities confirmed that the danger had passed. The agency urged people to stay away from windows, disconnect electrical devices, avoid contact with water and metallic objects and to follow updates from official sources.

Otis strengthened from a tropical storm into a major hurricane within only about 12 hours before it made landfall at 1:25 a.m. Eastern, according to the hurricane center. The storm slammed into Mexico's coast with maximum sustained winds of 165 mph and hurricane-force winds extending up to 30 miles from its center. No long after making landfall it was downgraded to a Category 4 storm, with maximum sustained winds of 130 mph.

The hurricane center warned that "catastrophic damage" was likely as the eye of the storm moved onshore.

It was forecast to bring anywhere from 8 to 20 inches of rain through Thursday across the Mexican states of Guerrero and Oaxaca, and may also cause "life-threatening coastal flooding."

The hurricane center warned of "extremely destructive winds near the core" of Otis, with powerful gusts posing a risk to the upper floors of high-rise buildings.

A storm is deemed a major hurricane when it reaches Category 3 or above on the Saffir-Simpson Hurricane Wind Scale due to the potential for "significant loss of life and damage," per the hurricane center.

A hurricane warning was in effect for Punta Maldonado west to Zihuatanejo.

Mexico's army and navy deployed more than 8,000 troops to Guerrero, an impoverished state plagued by violence linked to organized crime, with specialized equipment to aid in rescues. 

Authorities closed Acapulco's port, home to some 300 fishing boats. The beach city, which has a population of about one million, is a major tourist destination.

"We're on maximum alert," Acapulco's Mayor Abelina López said Tuesday night, according to the AP, urging residents to either stay home or seek safety in one of the shelters set up in the city. 

Danielle Banks, meteorologist for The Weather Channel, said Otis was expected to weaken after making landfall, and the hurricane center said Otis would "likely dissipate over southern Mexico" by Wednesday night.