Tropical Storm Rafael strengthening, headed toward Bermuda

(CNN) -- Tropical Storm Rafael churned in the central Atlantic early Monday as it neared hurricane strength, forecasters said.

The storm packed powerful 70 mph winds Monday morning and was centered about 290 miles (467 kilometers) north-northeast of San Juan, Puerto Rico, according to the National Hurricane Center in Miami. It was swirling north-northwest at 9 mph, forecasters said.

"Strengthening is forecast ... and Rafael is expected to become a hurricane today," the hurricane center said.

A projection map shows Rafael headed toward Bermuda later this week.

Officials there issued a tropical storm watch Sunday and told residents that they expected the storm to affect the British territory Tuesday.

The island's top emergency official warned that strong winds and rough seas were likely.

"The storm is expected to strengthen to a Category 1 hurricane as it passes the island, so I urge residents to be prepared and monitor the storm for any change in strength and direction," said Wayne Perinchief, chairman of Bermuda's Emergency Measures Organization.

A tropical storm watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

While the National Hurricane Center predicted Rafael would stay well to the east of the Bahamas through Monday night, it did warn of life-threatening surf conditions and rip currents on the eastward-facing beaches of the Bahamas over the next few days.

Forecasters expect Rafael to bring between 1 and 3 additional inches of rain over the northern Leeward Islands, with some pockets getting as much as 12 inches.

"These rains could cause life-threatening flash floods and mudslides, especially in areas of mountainous terrain," the hurricane center said.

CNN's Chandler Friedman contributed to this report.
 
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