Tropical Storm Otto strengthened into a hurricane Friday as it moved northeastward over the open Atlantic, posing no immediate threat to land, the National Hurricane Center said.
Otto, the 15th named storm of the busy 2010 Atlantic hurricane season and the eighth hurricane, was packing top sustained winds of 80 miles per hour by late Friday afternoon, making it a Category 1 hurricane on the five-step Saffir-Simpson scale of intensity.
It was located about 410 miles southeast of Bermuda, heading to the northeast over the open sea well away from the East Coast.
The Miami-based center said Otto was likely to gain more strength before weakening by Sunday.
Although far from land, the storm could still cause heavy rains in the Caribbean's north Leeward Islands, the Virgin Islands, Puerto Rico and the Dominican Republic.
"These rains could produce life-threatening flash floodsand mudslides," the center said.
The six-month Atlantic hurricane season that ends Nov. 30 has seen five major hurricanes so far out of the eight which have formed, but the United States has so far escaped a significant landfall impact.
On Wednesday, raging floodwaters from Otto overturned cars, toppled power lines and washed out roads in the northeastern Caribbean.
The Associated Press and Reuters contributed to this report.