Tropical Storm Harvey forms while 2 other systems threaten the Atlantic

With maximum sustained winds of 40 mph, Tropical Storm Harvey is moving steadily through the Caribbean on its way towards Central America and southern Mexico, the National Hurricane Center reports.

The storm is moving west at about 18 mph, and is located between Barbados and the Windward Islands. It is not expected to significantly strengthen until it enters the western Caribbean, where warmer waters might allow it to quickly gain momentum and approach hurricane strength before it makes landfall.

Air Force Reserve Hurricane Hunter aircraft flew into the storm Friday morning at sunrise.

Tropical storm warnings are in effect for the islands of Martinique, St. Lucia, St. Vincent and the Grenadines, while a watch is still in effect for Dominica. The government of Barbados has called off a warning issued there.

The NHC is tracking a second disturbance several hundred miles east of Harvey with a chance of becoming a tropical depression at some point on Friday. Upper level winds might prevent it from crossing that threshold for the time being, though. The system is moving west-northwest at around 20 mph and is given a 70 percent chance of developing into a tropical cyclone within the next two to five days.

Several hundred miles east of the second disturbance is a third system. It is given a 10 percent chance of developing into a tropical cyclone within the next two days and a 40 percent chance in the next five, though the NHC believe that conditions will become more favorable to its development early next week. It is currently moving west-northwest to northwest at about 20 mph.

This story was originally published August 18, 2017 at 11:40 AM with the headline "Tropical Storm Harvey forms while 2 other systems threaten the Atlantic."