Hurricane Sam now a Category 4 storm; Teresa dwindling

Loading Video…

This browser does not support the Video element.

Experts say hurricanes are getting stronger for several reasons

Nasty hurricanes that cause billions of dollars in damage are hitting more often.

Far from land, Hurricane Sam strengthened into a Category 4 hurricane in the Atlantic Ocean on Saturday.

No coastal watches or warnings were in effect for Sam, which was about 1,025 miles (1,655 kilometers) east-southeast of the northern Leeward Islands in the Caribbean Sea on Saturday evening. It was moving west-northwest at 10 mph (17 kph).

The U.S. National Hurricane Center in Miami said Sam had maximum sustained winds of 140 mph (220 kph). Forecasters said Sam could get even stronger Sunday morning with winds of 150 mph (240 kph).

RELATED: Subtropical Storm Teresa forms; Hurricane Sam could reach Category 4 status this weekend

Swells from the storm could cause dangerous rip current conditions off the coast of the Lesser Antilles early next week, officials said.

The U.S. National Hurricane Center in Miami says Sam has maximum sustained winds of 110 mph. (Credit: NOAA Satellites via Storyful)

Meanwhile, Teresa, which had been a subtropical storm, faded to a remnant low Saturday, about 150 miles (240 kph) north of Bermuda.