Miami (CNN) -- A tropical storm watch was issued for Bermuda on Tuesday ahead of newly formed Tropical Storm Sean, forecasters said.
Sean formed early Tuesday, midway between Bermuda and the Bahamas, the Miami-based National Hurricane Center said. As of midday Tuesday, the center of Sean was located about 425 miles southwest of Bermuda.
The storm's maximum sustained winds were at 45 mph, with higher gusts, forecasters said. Some increase in strength was possible over the next 48 hours, but computer models showed Sean remaining below hurricane intensity until it dissipates this weekend over the Atlantic.
Sean had been nearly stationary earlier Thursday but was expected to begin moving slowly west-northeast later in the day, turning northwest by Wednesday and then northward Thursday.
Computer models showed the center of Sean passing north of Bermuda before heading into the Atlantic. But, forecasters said, tropical storm conditions would be possible on the island late Thursday. Tropical storm-force winds extended outward up to 380 miles, primarily to the north of the center, the Hurricane Center said.
Swells generated by Sean are forecast to affect portions of the southeastern United States over the next two days, forecasters said, and can spawn potentially life-threatening surf and rip currents.