The storm was churning northwest on Monday night from the Atlantic Ocean around 450 miles south of Bermuda, with gusts as high as 160 mph.
Although experts believe Katia may veer away from the East Coast later this week, large swells from the hurricane could still cause life-threatening coastal surf and rip currents.
The storm has now reached the second-highest level on the five-step Saffir-Simpson intensity scale as it continued its route over Bermuda and the Caribbean.
A spokesperson for the National Hurricane Center, Miami, said: 'Large swells generated by Katia are expected to affect most of the East Coast of the United States, Bermuda, the Greater Antilles and east-facing beaches of the Bahamas during the next few days. Read More