Hurricane Franklin gains strength, takes aim at Bermuda -US NHC

(Reuters) - Hurricane Franklin is forecast to become the Atlantic's first major hurricane of the season on Monday and is on track to pass close to Bermuda on Wednesday, the U.S. National Hurricane Center (NHC) said on Sunday.

At around 11 p.m. Eastern time (0300 GMT), Franklin was about 530 miles (855 km) southwest of Bermuda with maximum sustained winds nearing 105 mph (165 kph), the Miami-based center said in an advisory.

"Additional strengthening is forecast, and Franklin is forecast to become a major hurricane on Monday," the advisory said.

A tropical storm with maximum sustained winds of above 110 mph (177 kph) or higher is considered a major hurricane.

Franklin is expected turn away from the U.S. eastern seaboard in the early part of the week but pass near the island of Bermuda on Wednesday, an NHC map shows.

The NHC said swells generated by Franklin were beginning to affect Bermuda on Sunday night.

"These swells are expected to spread toward the east coast of the United States during the next couple of days, likely resulting in life-threatening surf and rip current conditions," it said in the advisory.

This year's Atlantic hurricane season, which runs from June 1 to Nov. 30, is expected to have 18 named tropical storms, nine of which become hurricanes, four of them major, according to forecasters from Colorado State University.

A separate storm, Idalia, is expected to become a hurricane and could cause scattered flash and urban flooding across portions of the west coast of Florida, the Panhandle, and southern Georgia late Tuesday night through Wednesday, according to the NHC.

(Reporting by Simon Lewis, additional reporting by Deep Vakil in Bengaluru; Editing by Chris Reese and Lincoln Feast)