Miami (CNN) -- As the remnants of what had been Tropical Storm Ophelia fizzled in the Caribbean, another storm -- Philippe -- continued to gain strength Sunday in the eastern Atlantic Ocean, the National Hurricane Center reported.
No coastal warnings or watches are yet in effect for Tropical Storm Philippe, which is about 500 miles (805 kilometers) west-southwest of the Cape Verde Islands and still thousands of miles from the nearest Caribbean islands.
It has grown more powerful in recent days with maximum sustained winds of 60 mph early Sunday evening, 20 mph stronger than those reported 24 hours earlier. Tropical storm-force winds of 40 mph or more extended out 60 miles from its center.
The hurricane center predicts that Philippe will become a hurricane, meaning it will have sustained winds of at least 74 mph, by late Monday.
The storm is now heading northwest at around 12 mph, with a gradual turn more northward -- and a slight slowdown -- expected "over the next couple of days," according to the center.
The threat is diminishing, meanwhile, from another system that is much closer to North and South America.
Ophelia lost its status as a tropical storm on Sunday, when it sported sustained winds of 35 mph, reports the hurricane center.
At 5 p.m. ET Sunday, its center was 145 miles east of the northern Leeward Islands.
The hurricane center noted that what had been Ophelia "is expected to weaken and dissipate" further in the coming days.