The first named storm of the year has formed off the southeastern U.S. coast, more than three weeks ahead of the official start of the Atlantic hurricane season.
The National Hurricane Center in Miami says subtropical storm Andrea has top sustained winds of around 72 kilometers per hour and does not appear to be strengthening significantly.
But the center has issued a tropical storm watch for parts of the southern states of Georgia and Florida, meaning that tropical storm conditions are possible within the watch area within the next 36 hours.
Subtropical storms are usually weaker than hurricanes and tropical storms, which get their power from warm ocean water at their centers.
The hurricane center says the most significant impact for land areas will be gusty winds and high surf along beaches.
Some information for this report was provided by AP.