(CNN) -- The powerful but compact Hurricane Raymond drifted toward southern Mexico's Pacific coast Monday evening as it dumped heavy rains north of Acapulco, forecasters reported.
At 8 p.m. (11 p.m. ET), Raymond was a Category 3 storm -- a major hurricane -- with top winds of 120 mph (193 kph). After sitting still for most of the day, it began moving slowly toward shore and was centered about 135 miles (217 kilometers) west-southwest of Acapulco, the U.S.-based National Hurricane Center reported.
It had weakened slightly and its worst punch remained far out to sea, since hurricane-force winds extended just 25 miles from the eye. It was moving eastward at 2 mph, and its movement over the next day was expected to be "slow and erratic," forecasters said.
The hurricane center predicts Raymond will lose steam Tuesday and turn westward into the Pacific Ocean on Wednesday. But before then, it's projected to dump 2 to 4 inches of rain on the coast, and there may be areas in Michoacan and Guerrero states that receive as much as 8 inches.
"These rains could produce life-threatening flash floods and mudslides," forecasters noted.
A hurricane warning was posted for about 140 miles of coast, from the city of Lazaro Cardenas to Tecpan de Galeana, about 65 miles north of Acapulco. The warning means winds of 74 mph or higher are expected in the next 36 hours, and the storm could produce produce "significant coastal flooding" and "large and destructive waves," the hurricane center said.
A hurricane watch and tropical storm warning was posted from Acapulco to Tecpan de Galeana, meaning hurricane conditions are possible within two days, and winds of 39 mph or higher are expected within 36 hours.
Raymond quickly strengthened overnight off the south-central coast, which was was hit hard by another storm in September. That storm, Manuel, triggered deadly mudslides and left about 40,000 tourists stranded in Acapulco, a popular tourist destination.
On the other side of the continent, meanwhile, a tropical depression in the Atlantic Ocean has become Tropical Storm Lorenzo, the hurricane center said Monday. The storm was 635 miles east-southeast of Bermuda on Monday evening, moving into the deep Atlantic.
The storm had top winds of 40 mph, and it was moving north-northeast at 7 mph. Lorenzo was expected to start fading Wednesday without reaching hurricane strength, forecasters projected.
CNN's Ed Payne contributed to this report.